2016 Vol. 34 No. 3
2016, 34(3): 325-339.
DOI: 10.11913/PSJ.2095-0837.2016.30325
Abstract：
Many doubts and difficulties still exist in regards to the taxonomic treatment of the species complex in the genus Epimedium. For example, the E. franchetii species complex consists of four taxa difficult to distinguish, namely, E. franchetii Stearn, E. baojingense Q.L. Chen et B.M. Yang, E. zhushanense K.F. Wu et S.X. Qian, and E. lishihchenii Stearn. To understand the morphological characters and variation patterns of the E. franchetii species complex, a comprehensive herbarium specimen inspection and field investigation (during flowering periods) were carried out based on the "population" concept. Results showed that E. zhushanense was the most unique species due to its purple spur, making it the easiest to distinguish. However, the remaining taxa were very similar in flower and inflorescence characters, and key features among taxa were complex and unclear. For example, the contrast between the compact rhizome of E. franchetii and the long-creeping rhizome of E. lishihchenii appeared to be neither stable nor reliable. In the present study, 20% of individuals from the population collected from Lushan (type locality) had compact rhizomes. Although closely resembling E. franchetii in flower, inflorescence and rhizome, E. lishihchenii diverged by having different hairs on the underside of the leaflets. Specifically, E. franchetii had leaflets with short bristle-like hairs, while E. lishihchenii had multicellular long hairs. An interesting population (JXJA) distributed near Lushan had the hair of E. lishihchenii, but rhizome of E. franchetii. This population was defined as a transition type. In addition, E. baojingense was closely allied to E. franchetii, but differed in the petiolule, petiole and flowering stem, with pubescent hairs densest at the nodes and with long multicellular hairs on the leaflets. According to our field investigations, however, the density of hairs depended on the individuals and/or populations, and was often densest when young and gradually thinned in old age. The color of the pubescent hairs was not confined to dark yellow, but ranged from white on young twigs, to yellow when mature, and dark yellow when old. In addition, two populations (HBMP and HBFX), which were transition types between E. baojingense and E. franchetii, were observed with sparse hairs on the petioles, petiolules and flowering stems. A high-morphology-population structure, estimated by the unweighted pair group method with averaging (UPGMA) cluster analysis, was observed. This method allowed for the separation of the populations into three groups. The results suggested that E. zhushanense was a good and independent species, but the rest were complicated and close. Therefore, E. zhushanense should be removed from the E. franchetii species complex. Both E. franchetii and E. lishihchenii were originally described from cultivated plants by Stearn, which appeared to have fairly narrow species concepts. As far as E. franchetii and E. baojingense are concerned, they are geographically sympatrically distributed, with the fundamental difference being their leaf hairs. Therefore, E. baojingense should be treated as E. franchetii var. baojingense (ecological race). Both E. lishihchenii and E. franchetii have isolated distribution, with definite differences in leaf hair and rhizome styles. Thus, E. lishihchenii should be treated as E. franchetii ssp. lishihchenii (geographical race).
Many doubts and difficulties still exist in regards to the taxonomic treatment of the species complex in the genus Epimedium. For example, the E. franchetii species complex consists of four taxa difficult to distinguish, namely, E. franchetii Stearn, E. baojingense Q.L. Chen et B.M. Yang, E. zhushanense K.F. Wu et S.X. Qian, and E. lishihchenii Stearn. To understand the morphological characters and variation patterns of the E. franchetii species complex, a comprehensive herbarium specimen inspection and field investigation (during flowering periods) were carried out based on the "population" concept. Results showed that E. zhushanense was the most unique species due to its purple spur, making it the easiest to distinguish. However, the remaining taxa were very similar in flower and inflorescence characters, and key features among taxa were complex and unclear. For example, the contrast between the compact rhizome of E. franchetii and the long-creeping rhizome of E. lishihchenii appeared to be neither stable nor reliable. In the present study, 20% of individuals from the population collected from Lushan (type locality) had compact rhizomes. Although closely resembling E. franchetii in flower, inflorescence and rhizome, E. lishihchenii diverged by having different hairs on the underside of the leaflets. Specifically, E. franchetii had leaflets with short bristle-like hairs, while E. lishihchenii had multicellular long hairs. An interesting population (JXJA) distributed near Lushan had the hair of E. lishihchenii, but rhizome of E. franchetii. This population was defined as a transition type. In addition, E. baojingense was closely allied to E. franchetii, but differed in the petiolule, petiole and flowering stem, with pubescent hairs densest at the nodes and with long multicellular hairs on the leaflets. According to our field investigations, however, the density of hairs depended on the individuals and/or populations, and was often densest when young and gradually thinned in old age. The color of the pubescent hairs was not confined to dark yellow, but ranged from white on young twigs, to yellow when mature, and dark yellow when old. In addition, two populations (HBMP and HBFX), which were transition types between E. baojingense and E. franchetii, were observed with sparse hairs on the petioles, petiolules and flowering stems. A high-morphology-population structure, estimated by the unweighted pair group method with averaging (UPGMA) cluster analysis, was observed. This method allowed for the separation of the populations into three groups. The results suggested that E. zhushanense was a good and independent species, but the rest were complicated and close. Therefore, E. zhushanense should be removed from the E. franchetii species complex. Both E. franchetii and E. lishihchenii were originally described from cultivated plants by Stearn, which appeared to have fairly narrow species concepts. As far as E. franchetii and E. baojingense are concerned, they are geographically sympatrically distributed, with the fundamental difference being their leaf hairs. Therefore, E. baojingense should be treated as E. franchetii var. baojingense (ecological race). Both E. lishihchenii and E. franchetii have isolated distribution, with definite differences in leaf hair and rhizome styles. Thus, E. lishihchenii should be treated as E. franchetii ssp. lishihchenii (geographical race).
2016, 34(3): 340-351.
DOI: 10.11913/PSJ.2095-0837.2016.30340
Abstract：
With many lakes, rivers, and marshes, the middle-lower Yangtze and Sanjiang plains are the two largest alluvial floodplains in China. After extensive surveys of the two areas, wild species of Trapa were found to be abundant in the two plains, and included 42 populations consisting of nine species (T. maximowiczii, T. incisa, T. quadrispinosa, T. bispinosa, T. japonica, T. manshurica, T. macropoda, T. octotuberculata, and T. mammillifer) and three variants (T. natans var . pumila, T. quadrispinosa var. yongxiuensis,and T. pseudoincisa var. nanchangensis). The morphological plasticity and taxonomic significance of the wild species of Trapa were evaluated using 16 classification characters. Results showed that: (1) the species and variants of Trapa were divided into two groups based on nut size and snout. Group A contained two species, T. maximowiczii and T. incisa; the remaining seven species and three variants were included in Group B; (2) for the five species and two variants with pseudohorns, cluster analysis of the morphological characters showed that T. maximowiczii and T. incisa were clustered together and separated from the other species and variants; and, (3) low taxonomic values were found for the characters of tubercles on nuts, leaves and petiole swellings. In conclusion, nut size and the morphology of the snout and pseudohorn offered the best diagnostic criteria for the classification of Trapa.
With many lakes, rivers, and marshes, the middle-lower Yangtze and Sanjiang plains are the two largest alluvial floodplains in China. After extensive surveys of the two areas, wild species of Trapa were found to be abundant in the two plains, and included 42 populations consisting of nine species (T. maximowiczii, T. incisa, T. quadrispinosa, T. bispinosa, T. japonica, T. manshurica, T. macropoda, T. octotuberculata, and T. mammillifer) and three variants (T. natans var . pumila, T. quadrispinosa var. yongxiuensis,and T. pseudoincisa var. nanchangensis). The morphological plasticity and taxonomic significance of the wild species of Trapa were evaluated using 16 classification characters. Results showed that: (1) the species and variants of Trapa were divided into two groups based on nut size and snout. Group A contained two species, T. maximowiczii and T. incisa; the remaining seven species and three variants were included in Group B; (2) for the five species and two variants with pseudohorns, cluster analysis of the morphological characters showed that T. maximowiczii and T. incisa were clustered together and separated from the other species and variants; and, (3) low taxonomic values were found for the characters of tubercles on nuts, leaves and petiole swellings. In conclusion, nut size and the morphology of the snout and pseudohorn offered the best diagnostic criteria for the classification of Trapa.
2016, 34(3): 352-360.
DOI: 10.11913/PSJ.2095-0837.2016.30352
Abstract：
Exploring the spatial patterns and niche characteristics of desert plant populations is helpful in elucidating the community dynamic mechanisms and vegetation restoration in desert-oasis ecotones. Based on vegetation investigation data of three transects (50 m wide and 900 m length), the spatial distribution patterns, interspecific associations, and niche characteristics of the main plant populations in the desert-oasis ecotone of Tarim basin were analyzed using spatial point pattern analysis and niche indexes. Results showed that Populus euphratica Oliv., Tamarix ramosissima Ledeb., and Glycyrrhiza inflate Bat.had higher importance values and niche widths, indicating better ability to compete for resources against other species with narrow niches, stronger ecological adaptability, and dominance of community structure dynamics and the environment. The values of niche overlap among the main plant populations were generally high, especially among herbaceous species. The distribution pattern indicated that desert plants in drought habitats had convergent adaptation, a low tendency of niche differentiation and intense interspecific competition for resources. The spatial patterns of dominant populations were different; T. ramosissima and G. inflate populations showed random distribution and aggregation distribution at the 0-25 m scale, respectively; P. euphratica populations showed an aggregated distribution at short distances (≤ 5 m) and random distribution with scale increase; P. euphratica vs T. ramosissima, P. euphratica vs G. inflate, and T. ramosissima vs G. inflate showed significantly negative spatial associations at the < 4 m, ≤ 16 m, and ≤ 25 m scales, respectively, and interspecific competition exclusion was significant. Convergent adaptation and interspecific competition were the main driving factors for community succession and restricted species coexistence under the condition of scarce resources.
Exploring the spatial patterns and niche characteristics of desert plant populations is helpful in elucidating the community dynamic mechanisms and vegetation restoration in desert-oasis ecotones. Based on vegetation investigation data of three transects (50 m wide and 900 m length), the spatial distribution patterns, interspecific associations, and niche characteristics of the main plant populations in the desert-oasis ecotone of Tarim basin were analyzed using spatial point pattern analysis and niche indexes. Results showed that Populus euphratica Oliv., Tamarix ramosissima Ledeb., and Glycyrrhiza inflate Bat.had higher importance values and niche widths, indicating better ability to compete for resources against other species with narrow niches, stronger ecological adaptability, and dominance of community structure dynamics and the environment. The values of niche overlap among the main plant populations were generally high, especially among herbaceous species. The distribution pattern indicated that desert plants in drought habitats had convergent adaptation, a low tendency of niche differentiation and intense interspecific competition for resources. The spatial patterns of dominant populations were different; T. ramosissima and G. inflate populations showed random distribution and aggregation distribution at the 0-25 m scale, respectively; P. euphratica populations showed an aggregated distribution at short distances (≤ 5 m) and random distribution with scale increase; P. euphratica vs T. ramosissima, P. euphratica vs G. inflate, and T. ramosissima vs G. inflate showed significantly negative spatial associations at the < 4 m, ≤ 16 m, and ≤ 25 m scales, respectively, and interspecific competition exclusion was significant. Convergent adaptation and interspecific competition were the main driving factors for community succession and restricted species coexistence under the condition of scarce resources.
2016, 34(3): 361-370.
DOI: 10.11913/PSJ.2095-0837.2016.30361
Abstract：
Straddling the Henan and Hubei Provinces of China, Jigong Mountain National Nature Reserve (JMNNR) (31°46'~ 31°52' N, 114°01' ~ 114°06' E) of Xinyang has a forest ecosystem characteristic of north sub-tropical to warm temperate transitional zones. The average temperature of Xinyang has risen significantly between 1951 and 2010, accompanied by widely oscillating annual precipitation that exhibited no discernible trend. Between 1994 and 2014, the number of alien invasive plants (AIPs) increased from 49 to 60 in JMNNR, with the newly arrived species consisting of four species of Compositae, two species of Leguminosae, and one species each of Amaranthaceae, Cruciferae, Euphorbiaceae, Oxalidaceae, and Pontederiaceae. The invasive species mostly originated from America, Europe, Asia, and Africa, with those of American origin accounting for more than 50.0% of total invasive species in both 1994 and 2014. More than 95% of the invasive species in JMNNR were terrestrial. In both 1994 and 2014, annuals outnumbered biennials, which in turn outnumbered perennials. Intentional introduction has been the most damaging invasion pathway, followed by unintentional introduction and then naturalization. Of the newly invasive plants, nine reproduced via seed dispersal. To protect the biodiversity of the nature reserve, it is important to strengthen the monitoring and management of terrestrial alien herbaceous plants, especially those from the America and those that use seeds for reproduction.
Straddling the Henan and Hubei Provinces of China, Jigong Mountain National Nature Reserve (JMNNR) (31°46'~ 31°52' N, 114°01' ~ 114°06' E) of Xinyang has a forest ecosystem characteristic of north sub-tropical to warm temperate transitional zones. The average temperature of Xinyang has risen significantly between 1951 and 2010, accompanied by widely oscillating annual precipitation that exhibited no discernible trend. Between 1994 and 2014, the number of alien invasive plants (AIPs) increased from 49 to 60 in JMNNR, with the newly arrived species consisting of four species of Compositae, two species of Leguminosae, and one species each of Amaranthaceae, Cruciferae, Euphorbiaceae, Oxalidaceae, and Pontederiaceae. The invasive species mostly originated from America, Europe, Asia, and Africa, with those of American origin accounting for more than 50.0% of total invasive species in both 1994 and 2014. More than 95% of the invasive species in JMNNR were terrestrial. In both 1994 and 2014, annuals outnumbered biennials, which in turn outnumbered perennials. Intentional introduction has been the most damaging invasion pathway, followed by unintentional introduction and then naturalization. Of the newly invasive plants, nine reproduced via seed dispersal. To protect the biodiversity of the nature reserve, it is important to strengthen the monitoring and management of terrestrial alien herbaceous plants, especially those from the America and those that use seeds for reproduction.
2016, 34(3): 371-380.
DOI: 10.11913/PSJ.2095-0837.2016.30371
Abstract：
Based on field investigation and morphological taxonomy, the species composition and diversity characteristics of medicinal plants in the Beita Mountains of Xinjiang were studied. Our results showed there were 60 species of medicinal plants in the Beita Mountains belonging to 44 genera and 24 families, and included 16 rare and endangered medicinal plants. The 60 species were predominantly distributed in single-family or single-genus. The flora characteristics exhibited obvious temperate floristic elements, and were close with Mediterranean, western Asian and central Asian elements. Tropical elements were rare. Perennial herb species were dominant in terms of plant life type, with 29 species of perennial medicinal herbs accounting for 48.33% of total medicinal plants in the Beita Mountains. According to ecotype of the medicinal plants, Mesophytes were the most common, while Xeromorphic structure was the most obvious. The use of the whole plant, root and stem and leaf as the medicinal organ material accounted for 43.33%, 15%, and 11.66% of the total number of medicinal plants, respectively. The results of this study not only provide important background information for the protection of medicinal plants, but also provide a scientific basis for research on the biodiversity of the Beita Mountains.
Based on field investigation and morphological taxonomy, the species composition and diversity characteristics of medicinal plants in the Beita Mountains of Xinjiang were studied. Our results showed there were 60 species of medicinal plants in the Beita Mountains belonging to 44 genera and 24 families, and included 16 rare and endangered medicinal plants. The 60 species were predominantly distributed in single-family or single-genus. The flora characteristics exhibited obvious temperate floristic elements, and were close with Mediterranean, western Asian and central Asian elements. Tropical elements were rare. Perennial herb species were dominant in terms of plant life type, with 29 species of perennial medicinal herbs accounting for 48.33% of total medicinal plants in the Beita Mountains. According to ecotype of the medicinal plants, Mesophytes were the most common, while Xeromorphic structure was the most obvious. The use of the whole plant, root and stem and leaf as the medicinal organ material accounted for 43.33%, 15%, and 11.66% of the total number of medicinal plants, respectively. The results of this study not only provide important background information for the protection of medicinal plants, but also provide a scientific basis for research on the biodiversity of the Beita Mountains.
2016, 34(3): 381-390.
DOI: 10.11913/PSJ.2095-0837.2016.30381
Abstract：
Phellodendron amurense Rupr. is an endangered species and common medicinal plant with a long history in China. However, wild resources suffered severe damage from the 1960s to 1990s, and have, thus far, exhibited poor recovery. In this study, we researched population density and structure based on an extensive survey of 38 wild populations in the Yanshan, Qianshan, Changbaishan, Zhangguangcailing and Xiaoxing'anling mountains in norther and northeastern China, and applied HPLC to research the regional characteristics of alkaloid composition, including that of berberine, palmatine, phellodendrine, magnoflorine, and jatrorrhizine. The population structure of P. amurense showed a spindle shape, with the percentage of young and adult individuals being 13.9% and 68.0%, respectively. Overall, this showed a severe recession trend and seriously threatened condition due to the low numbers of young plants and insufficient natural regeneration. Chemical data showed that berberine, palmatine, phellodendrine, and total alkaloid content in P. amurense was the highest in Qianshan Mountain and the lowest in Xiaoxing'anling Mountain, with both showing significant differences compared with contents from the other three mountains. We conclud that the wild population distribution area of P. amurense is declining in China. Furthermore, the population age structure shows a decreasing trend and populations with few individuals have not managed self-restoration. The alkaloid content of P. amurense from low latitude areas, such as Qianshan Mountain, is significantly higher, which should be taken into consideration in regards to medicinal production.
Phellodendron amurense Rupr. is an endangered species and common medicinal plant with a long history in China. However, wild resources suffered severe damage from the 1960s to 1990s, and have, thus far, exhibited poor recovery. In this study, we researched population density and structure based on an extensive survey of 38 wild populations in the Yanshan, Qianshan, Changbaishan, Zhangguangcailing and Xiaoxing'anling mountains in norther and northeastern China, and applied HPLC to research the regional characteristics of alkaloid composition, including that of berberine, palmatine, phellodendrine, magnoflorine, and jatrorrhizine. The population structure of P. amurense showed a spindle shape, with the percentage of young and adult individuals being 13.9% and 68.0%, respectively. Overall, this showed a severe recession trend and seriously threatened condition due to the low numbers of young plants and insufficient natural regeneration. Chemical data showed that berberine, palmatine, phellodendrine, and total alkaloid content in P. amurense was the highest in Qianshan Mountain and the lowest in Xiaoxing'anling Mountain, with both showing significant differences compared with contents from the other three mountains. We conclud that the wild population distribution area of P. amurense is declining in China. Furthermore, the population age structure shows a decreasing trend and populations with few individuals have not managed self-restoration. The alkaloid content of P. amurense from low latitude areas, such as Qianshan Mountain, is significantly higher, which should be taken into consideration in regards to medicinal production.
2016, 34(3): 391-396.
DOI: 10.11913/PSJ.2095-0837.2016.30391
Abstract：
The relationship between seed germination characteristics and seed shape (three-dimensional variance of length, width, and height), seed volume, and surface/volume ratio were studied. We discussed the influence of seed shape and size on seed germination. The results showed that: (1) germination percentage and germination rate were both significantly positively correlated with variances in dimension and surface/volume ratio, and significantly negatively correlated with seed volume; (2) mean seed germination time was significantly negatively correlated with seed volume, but significantly positively correlated with seed surface/volume ratio, and the variances in dimension and seed volume had no obvious effects on mean germination time. Accordingly, small, elongated seeds had higher germination percentages and rates, while large, compact seeds showed a delay in germination. The small seeds had a larger surface/volume ratio, which might explain their higher germination percentage and rate. Our study provides a theoretical basis for the formation mechanism of a soil seed bank.
The relationship between seed germination characteristics and seed shape (three-dimensional variance of length, width, and height), seed volume, and surface/volume ratio were studied. We discussed the influence of seed shape and size on seed germination. The results showed that: (1) germination percentage and germination rate were both significantly positively correlated with variances in dimension and surface/volume ratio, and significantly negatively correlated with seed volume; (2) mean seed germination time was significantly negatively correlated with seed volume, but significantly positively correlated with seed surface/volume ratio, and the variances in dimension and seed volume had no obvious effects on mean germination time. Accordingly, small, elongated seeds had higher germination percentages and rates, while large, compact seeds showed a delay in germination. The small seeds had a larger surface/volume ratio, which might explain their higher germination percentage and rate. Our study provides a theoretical basis for the formation mechanism of a soil seed bank.
2016, 34(3): 397-405.
DOI: 10.11913/PSJ.2095-0837.2016.70001
Abstract：
A glycosyltransferase gene (LhsUGT) was cloned from Leonurus heterophyllus Sweet using rapid amplification of cDNA ends (RACE). The full length cDNA of LhsUGT was 1562 bp, with a 1368 bp open reading frame (ORF) encoding a 455 amino-acid protein (LhsUGT) and a molecular weight of 50.47 kD and isoelectric point of 5.52. By bioinformatics analysis, three secondary structures were discovered in LhsUGT, including 43.1% helix, 17.5% β-sheet and 39.4% random coil structural elements. There was a conserved PSPG domain at the C-terminal of LhsUGT, demonstrating that the enzyme encoded by LhsUGT belonged to the glucosyltransferase super family. Homology analysis by BLAST showed that the sequence similarities of glycosyltransferase between L. heterophyllus and other plants were 26.4% - 68.0%. Phylogenetic tree analysis indicated that LhsUGT might glycosylate simple phenolic compounds as it was found to be clustered with group L in Arabidopsis thaliana. SDS-PAGE analysis showed recombinant LhsUGT with approximate molecular weight of 69 kD was successfully expressed by a prokaryotic expression system, which contained His tags of 17.9 kD at the N-terminal and reached maximum expression level until 5 h after induction by IPTG (Isopropyl β-D-1-thiogalactopyranoside). The results in the study will lay the foundation for future studies on the biological functions of LhsUGT by enzymatic reactions in vitro.
A glycosyltransferase gene (LhsUGT) was cloned from Leonurus heterophyllus Sweet using rapid amplification of cDNA ends (RACE). The full length cDNA of LhsUGT was 1562 bp, with a 1368 bp open reading frame (ORF) encoding a 455 amino-acid protein (LhsUGT) and a molecular weight of 50.47 kD and isoelectric point of 5.52. By bioinformatics analysis, three secondary structures were discovered in LhsUGT, including 43.1% helix, 17.5% β-sheet and 39.4% random coil structural elements. There was a conserved PSPG domain at the C-terminal of LhsUGT, demonstrating that the enzyme encoded by LhsUGT belonged to the glucosyltransferase super family. Homology analysis by BLAST showed that the sequence similarities of glycosyltransferase between L. heterophyllus and other plants were 26.4% - 68.0%. Phylogenetic tree analysis indicated that LhsUGT might glycosylate simple phenolic compounds as it was found to be clustered with group L in Arabidopsis thaliana. SDS-PAGE analysis showed recombinant LhsUGT with approximate molecular weight of 69 kD was successfully expressed by a prokaryotic expression system, which contained His tags of 17.9 kD at the N-terminal and reached maximum expression level until 5 h after induction by IPTG (Isopropyl β-D-1-thiogalactopyranoside). The results in the study will lay the foundation for future studies on the biological functions of LhsUGT by enzymatic reactions in vitro.
2016, 34(3): 406-419.
DOI: 10.11913/PSJ.2095-0837.2016.30406
Abstract：
Arabidopsis thaliana DnaJ homolog 3 (AtJ3), an Arabidopsis chaperone, interacts with SOS2-like protein kinase 5 (PKS5) to form the AtJ3-PKS5 complex and achieves its function through repressing activity of PKS5 in vivo. Moreover, the AtJ3-PKS5 complex positively regulates plasma membrane H+-ATPase activity and is involved in exogenous ABA response in Arabidopsis. In this study, salt- and ABA-treated Arabidopsis AtJ3 and PKS5 mutants were explored to elucidate the function and mechanism of the AtJ3-PKS5 complex in the simultaneous regulation of membrane H+-ATPase activity and ABA response. Results showed that the AtJ3-PKS5 complex not only led to changes in the cytosolic pH value via regulation of plasma membrane H+-ATPase activity, but also activated expression of the ABA-related responsive genes under the two treatments. Additionally, exogenous application of ABA induced trafficking of AtJ3 from the nucleus to the cytoplasm to enhance H+-ATPase activity, indicating that the AtJ3-PKS5 complex functions in ABA-meditated pH homeostasis. Taken together, our results suggest that the AtJ3-PKS5 complex might serve as a key regulator in a crosstalk metabolic pathway of H+-ATPase activity regulation and exogenous ABA response.
Arabidopsis thaliana DnaJ homolog 3 (AtJ3), an Arabidopsis chaperone, interacts with SOS2-like protein kinase 5 (PKS5) to form the AtJ3-PKS5 complex and achieves its function through repressing activity of PKS5 in vivo. Moreover, the AtJ3-PKS5 complex positively regulates plasma membrane H+-ATPase activity and is involved in exogenous ABA response in Arabidopsis. In this study, salt- and ABA-treated Arabidopsis AtJ3 and PKS5 mutants were explored to elucidate the function and mechanism of the AtJ3-PKS5 complex in the simultaneous regulation of membrane H+-ATPase activity and ABA response. Results showed that the AtJ3-PKS5 complex not only led to changes in the cytosolic pH value via regulation of plasma membrane H+-ATPase activity, but also activated expression of the ABA-related responsive genes under the two treatments. Additionally, exogenous application of ABA induced trafficking of AtJ3 from the nucleus to the cytoplasm to enhance H+-ATPase activity, indicating that the AtJ3-PKS5 complex functions in ABA-meditated pH homeostasis. Taken together, our results suggest that the AtJ3-PKS5 complex might serve as a key regulator in a crosstalk metabolic pathway of H+-ATPase activity regulation and exogenous ABA response.
2016, 34(3): 420-429.
DOI: 10.11913/PSJ.2095-0837.2016.30420
Abstract：
Cell wall invertase gene promoter, EhcwINVP (1727 bp), was amplified from the genomic DNA of Elsholtzia haichowensis Sun by hiTAIL-PCR and genome walking PCR. Bioinformatics analysis showed that the promoter fragment contained multiple cis-acting elements involved in the regulation of hormones including abscisic acid, gibberellin, cytokinin, and tolerance to drought, low temperature, and heavy metals such as copper. The pCAMBIA1301 binary vector was digested with restriction enzymes to remove the 35S promoter that drove GUS expression and replaced with EhcwINVP sequences to generate the construct EhNcwINVP::GUS. Histochemical analyses of transgenic Arabidopsis thaliana L. plants indicated that the EhcwINVP promoter was capable of driving GUS expression, and GUS activity in the leaves and roots of transgenic A. thaliana plants increased by about 1.7 and 1.5 times that of the control under copper stress, respectively.
Cell wall invertase gene promoter, EhcwINVP (1727 bp), was amplified from the genomic DNA of Elsholtzia haichowensis Sun by hiTAIL-PCR and genome walking PCR. Bioinformatics analysis showed that the promoter fragment contained multiple cis-acting elements involved in the regulation of hormones including abscisic acid, gibberellin, cytokinin, and tolerance to drought, low temperature, and heavy metals such as copper. The pCAMBIA1301 binary vector was digested with restriction enzymes to remove the 35S promoter that drove GUS expression and replaced with EhcwINVP sequences to generate the construct EhNcwINVP::GUS. Histochemical analyses of transgenic Arabidopsis thaliana L. plants indicated that the EhcwINVP promoter was capable of driving GUS expression, and GUS activity in the leaves and roots of transgenic A. thaliana plants increased by about 1.7 and 1.5 times that of the control under copper stress, respectively.
2016, 34(3): 430-438.
DOI: 10.11913/PSJ.2095-0837.2016.30430
Abstract：
MiR408 is a highly conserved miRNA in plants and responds to copper availability by targeting genes encoding copper-containing proteins. Its expression is significantly affected by plant growth and development and environmental conditions. MiR408 is critical for the HY5-SPL7 gene network in Arabidopsis, and mediates a coordinated response to light and copper, illustrating its central role in the reaction of plants to the environment. Based on the genomic survey database of Salvia miltiorrhiza established in our lab, a 366 bp miR408 precursor sequence with stable stem loop structure was cloned and named Sm-MIR408. The 723 bp promoter region upstream of Sm-MIR408 was obtained by PCR. The GenBank accession numbers of Sm-MIR408 and the promoter sequence are KU360384 and KU360385, respectively. Bioinformatic analysis showed that the promoter region of Sm-MIR408 shared the same cis-acting elements as those of Ath-MIR408 in Arabidopsis thaliana and Osa-MIR408 in Oryza sativa, and included G-box, CGTCA-motif, TGACG-motif and GTAC-motif, whereas HSE and CATT-motif elements existed only in the Sm-MIR408 promoter region. Mature miR408 is highly conserved among different species. A phylogenetic tree of miR408 from different species showed that miR408 precursor sequences from monocotyledons were clustered on one branch and those from dicotyledons were clustered on another. Real-time quantitative PCR showed that the expression of Sm-MIR408 in the roots, stems, leaves and flowers of S. miltiorrhiza was the highest in the flowers and the lowest in the roots. Expression of Sm-MIR408 could be suppressed by methyl jasmonate, wounding, and continuous light or darkness. The cloning and expression analysis of Sm-MIR408 presented in this research has laid a foundation for studying the function of miR408 in S. miltiorrhiza in the future.
MiR408 is a highly conserved miRNA in plants and responds to copper availability by targeting genes encoding copper-containing proteins. Its expression is significantly affected by plant growth and development and environmental conditions. MiR408 is critical for the HY5-SPL7 gene network in Arabidopsis, and mediates a coordinated response to light and copper, illustrating its central role in the reaction of plants to the environment. Based on the genomic survey database of Salvia miltiorrhiza established in our lab, a 366 bp miR408 precursor sequence with stable stem loop structure was cloned and named Sm-MIR408. The 723 bp promoter region upstream of Sm-MIR408 was obtained by PCR. The GenBank accession numbers of Sm-MIR408 and the promoter sequence are KU360384 and KU360385, respectively. Bioinformatic analysis showed that the promoter region of Sm-MIR408 shared the same cis-acting elements as those of Ath-MIR408 in Arabidopsis thaliana and Osa-MIR408 in Oryza sativa, and included G-box, CGTCA-motif, TGACG-motif and GTAC-motif, whereas HSE and CATT-motif elements existed only in the Sm-MIR408 promoter region. Mature miR408 is highly conserved among different species. A phylogenetic tree of miR408 from different species showed that miR408 precursor sequences from monocotyledons were clustered on one branch and those from dicotyledons were clustered on another. Real-time quantitative PCR showed that the expression of Sm-MIR408 in the roots, stems, leaves and flowers of S. miltiorrhiza was the highest in the flowers and the lowest in the roots. Expression of Sm-MIR408 could be suppressed by methyl jasmonate, wounding, and continuous light or darkness. The cloning and expression analysis of Sm-MIR408 presented in this research has laid a foundation for studying the function of miR408 in S. miltiorrhiza in the future.
2016, 34(3): 439-445.
DOI: 10.11913/PSJ.2095-0837.2016.30439
Abstract：
Four cowpea varieties, ‘E Jiangdou 2’, ‘E Jiangdou 6’, ‘E Jiangdou 7’, and ‘Meiguo Didou’, provided by the Hubei Province Engineering Research Center were selected as research materials. We sprayed cytokinin on leaves in budding stage to study its effects on the abscission of flowers and pods in the field. At 7, 14, 28 and 42 d after spraying, we analyzed the yields and abscission rates of flowers and pods, and detected the enzyme activities of polygalacturonase and cellulase in premature shedding of flowers and pods.Results showed that after spraying cytokinin, the abscission rates of flowers and pods in different cultivars were lower than those in the control, but yields in different cultivars were higher, with the differences being highly significant (P < 0.01). Furthermore, the polyga-lacturonase activities of cowpea were significantly lower than those of the control at 14 d, 28 d and 42 d after spraying (P < 0.05), and significantly lower at 7 d after spraying (P < 0.01). The cellulase activities of fallen flowers and pods were significantly (P < 0.05) lower than those of the control at 7 d and 42 d after spraying, and significantly (P < 0.01) lower at 14 d and 28 d after spraying. The above results indicated that the activities of polygalacturonase and cellulase were regulated by spraying cytokinin, which resulted in reducing the abscission rate of flowers and pods and regulating yield in cowpea.
Four cowpea varieties, ‘E Jiangdou 2’, ‘E Jiangdou 6’, ‘E Jiangdou 7’, and ‘Meiguo Didou’, provided by the Hubei Province Engineering Research Center were selected as research materials. We sprayed cytokinin on leaves in budding stage to study its effects on the abscission of flowers and pods in the field. At 7, 14, 28 and 42 d after spraying, we analyzed the yields and abscission rates of flowers and pods, and detected the enzyme activities of polygalacturonase and cellulase in premature shedding of flowers and pods.Results showed that after spraying cytokinin, the abscission rates of flowers and pods in different cultivars were lower than those in the control, but yields in different cultivars were higher, with the differences being highly significant (P < 0.01). Furthermore, the polyga-lacturonase activities of cowpea were significantly lower than those of the control at 14 d, 28 d and 42 d after spraying (P < 0.05), and significantly lower at 7 d after spraying (P < 0.01). The cellulase activities of fallen flowers and pods were significantly (P < 0.05) lower than those of the control at 7 d and 42 d after spraying, and significantly (P < 0.01) lower at 14 d and 28 d after spraying. The above results indicated that the activities of polygalacturonase and cellulase were regulated by spraying cytokinin, which resulted in reducing the abscission rate of flowers and pods and regulating yield in cowpea.
2016, 34(3): 446-459.
DOI: 10.11913/PSJ.2095-0837.2016.30446
Abstract：
Desmodesmus insignis strain JNU24 was cultivated in BG-11 medium containing four different initial NaNO3 concentrations and dairy wastewater (DWW) diluted into four concentrations to compare its growth, starch production performance, and nitrogen and phosphorus removal capacity in DWW. Results indicated that the optimum nitrate concentrations and DWW concentration for growth were 9.0 mmol/L and 100%, respectively, in which biomass achieved was 6.23 g/L and 10.31 g/L, respectively. Compared with the BG-11 group, however, D. insignis showed a greater ability to grow and accumulate starch when cultivated with 75% DWW, in which the starch content, volumetric starch content, and productivity reached 50.9%, 4.86 g/L, and 405 mg·L-1·d-1 respectively. In addition, D. insignis removed 90.8% of nitrogen and 98.7% of phosphorus from DWW. Indoor scaled-up cultivation of D. insignis was carried out in vertical flat-plate glass photobioreactors based on optimum concentrations of BG-11 and DWW. The maximum biomass concentration, volumetric starch content, and productivity of D. insignis were obtained under 75% DWW, reaching 9.75 g/L, 4.75 g/L, and 230 mg·L-1·d-1, respectively, which were approximately two times greater than those obtained in the BG-11 group. These results showed that D. insignis could tolerant high nitrate concentrations in DWW, and could be applied on a large scale with cheap media. The D. insignis cells exhibited outstanding settling capacity, as inferred from their ability to settle within 90 min in 75% DWW after stopping aeration. In conclusion, D. insignis is a microalga that has the potential to produce starch and purify wastewater.
Desmodesmus insignis strain JNU24 was cultivated in BG-11 medium containing four different initial NaNO3 concentrations and dairy wastewater (DWW) diluted into four concentrations to compare its growth, starch production performance, and nitrogen and phosphorus removal capacity in DWW. Results indicated that the optimum nitrate concentrations and DWW concentration for growth were 9.0 mmol/L and 100%, respectively, in which biomass achieved was 6.23 g/L and 10.31 g/L, respectively. Compared with the BG-11 group, however, D. insignis showed a greater ability to grow and accumulate starch when cultivated with 75% DWW, in which the starch content, volumetric starch content, and productivity reached 50.9%, 4.86 g/L, and 405 mg·L-1·d-1 respectively. In addition, D. insignis removed 90.8% of nitrogen and 98.7% of phosphorus from DWW. Indoor scaled-up cultivation of D. insignis was carried out in vertical flat-plate glass photobioreactors based on optimum concentrations of BG-11 and DWW. The maximum biomass concentration, volumetric starch content, and productivity of D. insignis were obtained under 75% DWW, reaching 9.75 g/L, 4.75 g/L, and 230 mg·L-1·d-1, respectively, which were approximately two times greater than those obtained in the BG-11 group. These results showed that D. insignis could tolerant high nitrate concentrations in DWW, and could be applied on a large scale with cheap media. The D. insignis cells exhibited outstanding settling capacity, as inferred from their ability to settle within 90 min in 75% DWW after stopping aeration. In conclusion, D. insignis is a microalga that has the potential to produce starch and purify wastewater.
2016, 34(3): 460-468.
DOI: 10.11913/PSJ.2095-0837.2016.30460
Abstract：
Indocalamus decorus Q.H. Dai is a good ornamental and economic bamboo species, with high sensitivity to ecological variations in the environment. Different treatments of several key ecological factors, including bamboo seedling density, light, fertilization and water, were compared in regards to bamboo rhizome nutrient, mineral element, endogenous hormone and bud germination characteristic differences under various treatments, with lateral bud germination responses to ecological factors also analyzed. Results showed that: (1) Among nutritional components, mineral element and endogenous hormone content of the bamboo rhizome, protein, Mg, Fe, ABA, iPA, IAA, and Zr concentrations showed higher correlation with bamboo shoots germinating from the lateral buds, but soluble sugar and GA contents had higher correlation with bamboo rhizome germinating from the lateral buds. (2) I. decorus showed the best substance storage and bud germination characteristics under potting treatments with two rhizome sections, a matrix and fertilizer ratio of 8∶1, a 6-day watering interval, and without a shading net. (3) Different treatments resulted in complex changes in bamboo rhizome nutrients, mineral elements, and endogenous hormones, and further caused lateral bud germination differences. The differences of bamboo physiological response to environment ecological factors might also be caused by long-term environmental selection and genetic evolution. This study will be useful for the propagation and cultivation of this species.
Indocalamus decorus Q.H. Dai is a good ornamental and economic bamboo species, with high sensitivity to ecological variations in the environment. Different treatments of several key ecological factors, including bamboo seedling density, light, fertilization and water, were compared in regards to bamboo rhizome nutrient, mineral element, endogenous hormone and bud germination characteristic differences under various treatments, with lateral bud germination responses to ecological factors also analyzed. Results showed that: (1) Among nutritional components, mineral element and endogenous hormone content of the bamboo rhizome, protein, Mg, Fe, ABA, iPA, IAA, and Zr concentrations showed higher correlation with bamboo shoots germinating from the lateral buds, but soluble sugar and GA contents had higher correlation with bamboo rhizome germinating from the lateral buds. (2) I. decorus showed the best substance storage and bud germination characteristics under potting treatments with two rhizome sections, a matrix and fertilizer ratio of 8∶1, a 6-day watering interval, and without a shading net. (3) Different treatments resulted in complex changes in bamboo rhizome nutrients, mineral elements, and endogenous hormones, and further caused lateral bud germination differences. The differences of bamboo physiological response to environment ecological factors might also be caused by long-term environmental selection and genetic evolution. This study will be useful for the propagation and cultivation of this species.
2016, 34(3): 469-474.
DOI: 10.11913/PSJ.2095-0837.2016.30469
Abstract：
Through two-phase culture, we studied the effects of culture time extension and volume percentages of dibutylphthalate (DBP) on growth and secondary metabolite content in the adventitious roots of Tripterygium wilfordii Hook. f.. Results showed that adventitious root growth increased 1.06-fold when the volume percentage of DBP was 6% and addition of organic solvent was on day 6. Triptolide content in the root was 1.40-fold higher when the volume percentage of DBP was 2% and addition of organic solvent was on day 8. Triptolide yield in the two-phase culture was 1.48-fold higher than that of the control when the volume percentage of DBP was 2% and addition of organic solvent was on day 2. Thus, DBP in the medium was suitable for triptolide accumulation, but alkaloid accumulation was inhibited significantly. The contents of wilforgine and wilforine in the adventitious roots and yields of wilforgine and wilforine per flask were all lower than that of the control, regardless of the concentration of DBP added to the medium or the extension of culture time.
Through two-phase culture, we studied the effects of culture time extension and volume percentages of dibutylphthalate (DBP) on growth and secondary metabolite content in the adventitious roots of Tripterygium wilfordii Hook. f.. Results showed that adventitious root growth increased 1.06-fold when the volume percentage of DBP was 6% and addition of organic solvent was on day 6. Triptolide content in the root was 1.40-fold higher when the volume percentage of DBP was 2% and addition of organic solvent was on day 8. Triptolide yield in the two-phase culture was 1.48-fold higher than that of the control when the volume percentage of DBP was 2% and addition of organic solvent was on day 2. Thus, DBP in the medium was suitable for triptolide accumulation, but alkaloid accumulation was inhibited significantly. The contents of wilforgine and wilforine in the adventitious roots and yields of wilforgine and wilforine per flask were all lower than that of the control, regardless of the concentration of DBP added to the medium or the extension of culture time.
2016, 34(3): 475-487.
DOI: 10.11913/PSJ.2095-0837.2016.30475
Abstract：
The survival of multicellular organisms depends on the functional division of different types of cells. Although specific cell types share the same genome, they have unique developmental programs, as well as different abilities to play their role during development and respond to environmental variation. Thus, a key challenge in biology is to understand how genes are expressed in the right cells at the right time and at the right level. Recently, many novel tools have been developed for single-cell-omics research using cell-type-specific methods. These innovations enable us to understand the mechanisms of gene regulation in single cells and their adaptation to environmental changes with unprecedented resolution. The isolation of single-cell samples has long been a bottleneck to relevant study; however, there are some useful techniques available. In this paper, we discuss techniques for sample labeling, isolation and collection of single cells, -omics data analysis and validation for single-cell analysis, and their application for plant research.
The survival of multicellular organisms depends on the functional division of different types of cells. Although specific cell types share the same genome, they have unique developmental programs, as well as different abilities to play their role during development and respond to environmental variation. Thus, a key challenge in biology is to understand how genes are expressed in the right cells at the right time and at the right level. Recently, many novel tools have been developed for single-cell-omics research using cell-type-specific methods. These innovations enable us to understand the mechanisms of gene regulation in single cells and their adaptation to environmental changes with unprecedented resolution. The isolation of single-cell samples has long been a bottleneck to relevant study; however, there are some useful techniques available. In this paper, we discuss techniques for sample labeling, isolation and collection of single cells, -omics data analysis and validation for single-cell analysis, and their application for plant research.
2016, 34(3): 488-495.
DOI: 10.11913/PSJ.2095-0837.2016.30488
Abstract：
Due to the limitation of appropriate methods, the vast majority of research on plant traits has concentrated on above-ground tissues rather than root systems hindered by soil. Conventional root investigation methods such as soil cores, monoliths, and in-growth cores are inherently labour intensive, time-consuming and destructive. There is, therefore, an urgent need for a non-destructive but reliable method for the estimation of the structure and function of root systems in situ. Numerous studies have shown good correlations between electrical impedance parameters (capacitance, resistance and electrical impedance spectroscopy) and root weight and morphology with the measurement of roots under an external electric field. Recently, however, other researchers have argued that the understanding of the electrical behaviour of roots is still poor. This paper introduces the basic theory and measurement of bioimpedance, reviews the different outcomes of root research using bioimpedance, and suggests several questions in regard to the application of bioimpedance. The current research will provide a reference for studies examining non-destructive root systems in situ.
Due to the limitation of appropriate methods, the vast majority of research on plant traits has concentrated on above-ground tissues rather than root systems hindered by soil. Conventional root investigation methods such as soil cores, monoliths, and in-growth cores are inherently labour intensive, time-consuming and destructive. There is, therefore, an urgent need for a non-destructive but reliable method for the estimation of the structure and function of root systems in situ. Numerous studies have shown good correlations between electrical impedance parameters (capacitance, resistance and electrical impedance spectroscopy) and root weight and morphology with the measurement of roots under an external electric field. Recently, however, other researchers have argued that the understanding of the electrical behaviour of roots is still poor. This paper introduces the basic theory and measurement of bioimpedance, reviews the different outcomes of root research using bioimpedance, and suggests several questions in regard to the application of bioimpedance. The current research will provide a reference for studies examining non-destructive root systems in situ.
