Influence of high light stress on the photosynthesis of flag leaves of indica subspecies (cv. “Shanyou 63', sensitive to photoinhibition) and japonica subspecies (cv. “Wuyujing', resistant to photoin...Influence of high light stress on the photosynthesis of flag leaves of indica subspecies (cv. “Shanyou 63', sensitive to photoinhibition) and japonica subspecies (cv. “Wuyujing', resistant to photoinhibition) of rice ( Oryza sativa L.) was comparatively investigated. In both cultivars of rice, the excitation energy distribution between two photosystems was altered and the excitation energy transfer from light harvesting chlorophyll protein complexes to PSⅡ was inhibited by high light stress. These decreases were more pronounced in indica rice cultivar as compared to japonica one. The analysis of mild SDS_PAGE showed that in indica rice, high light stress almost disaggregated the trimer of light harvesting chlorophyll protein complexes of PSⅡ (LHC Ⅱ 1). The stress reduced the contents of internal antennae chlorophyll protein complexes of PSⅡ (CPa), light harvesting chlorophyll protein of PSⅠ (CPⅠa) and Chl a protein complex of PSⅠ reaction center (CPⅠ) as well as dimer of LHCⅡ (LHCⅡ 2) in indica rice. In japonica subspecies, however, high light stress depressed the contents of LHCⅡ 1, CPa and CPⅠa, but slightly impacted on CPⅠ content. Moreover, the increase in the contents of monomer of LHCⅡ by high light stress was found in both subspecies. In consistent with above results, analysis of polypeptide indicated that the amounts of 27 kD and 25 kD polypeptide of LHCⅡ in particular, as well as that of 21 kD polypeptide of CPⅠa were reduced by high light stress in both subspecies. It was found that, comparing with japonica rice, the stress pronouncedly diminished 43 kD and 47 kD proteins of CPa and 23 kD extrisic protein in indica rice.展开更多
[Objective] The aim was to study the effects of drought stress on contents of endogenous hormones in leaves of different clones of Liriodendron chinense×L. tulipifera. Drought-resistant Liriodendron chinense×...[Objective] The aim was to study the effects of drought stress on contents of endogenous hormones in leaves of different clones of Liriodendron chinense×L. tulipifera. Drought-resistant Liriodendron chinense×L. tulipifera clones NE25,NE78 and drought-sensitive Liriodendron chinense×L. tulipifera clones NE04,NE23 were selected as experimental materials to study the content changes of four kinds of endogenous hormones such as abscisic acid (ABA),indoleacetic acid (IAA),ribosylzeatin (ZR) and jasmonic acid (JA) in leaves of different clones under drought stress. [Result] Under drought stress,ABA was accumulated I leaves of different clones,however,the content changes in drought-resistant clones were not obvious; IAA content showed a decreasing trend,and the content changes n drought-resistant clones during later period of drought stress was decreased; JA content showed an increasing trend in leaves of drought-sensitive clones,indicating that drought-sensitive clones had to maintain higher contents of JA to resist drought stress. [Conclusion] The result of this study had provided scientific basis for the screening,planting and application of drougt-resistant clones of Liriodendron chinense×L. tulipifera.展开更多
A pot experiment was conducted in lath house to study the response of six month-old seedlings of sour orange (Citrus aurantium L.) irrigated with salinity water (1, 2 or 4 ds/m) for four month. The seedling was sp...A pot experiment was conducted in lath house to study the response of six month-old seedlings of sour orange (Citrus aurantium L.) irrigated with salinity water (1, 2 or 4 ds/m) for four month. The seedling was sprayed with putrescine at 0, 150 or 300 mg/L concentrations for three times with month interval, for investigation the effects of putrrescine spraying on hormonal changes in sour orange seedlings under salt stress. One month after the last putrescine application, the leaves of the vegetative shoots were picked for endogenous plant hormone determination. The results indicate that increasing level of irrigation water salinity to 4 ds/m significantly increased ABA, Put and SA; whereas, decreasing IAA and GA in leave. Spraying vegetative canopy with putreseine at 300 mg/L increased 1AA, SA, ABA and Put, while decreased GA. It can be concluded that the adverse effects of high salinity irrigated water on endogenous plant hormone can be ameliorated, to some extent, by exogenous application of Put at 150 mg/L or 300 mg/L concentration.展开更多
Tocopherols synthesized exclusively by photosynthetic organisms are major antioxidants in biomembranes.In plants,tocopherol cyclase(TC/VTE1) catalyzes the conversion of 2,3-dimethyl-5-phytyl-1,4-benzoquinone(DMPBQ) to...Tocopherols synthesized exclusively by photosynthetic organisms are major antioxidants in biomembranes.In plants,tocopherol cyclase(TC/VTE1) catalyzes the conversion of 2,3-dimethyl-5-phytyl-1,4-benzoquinone(DMPBQ) to γ-tocopherol.In the present study,OsVTE1,which encodes a rice tocopherol cyclase ortholog,was cloned and characterized.OsVTE1 was induced significantly by abiotic stresses such as high salt,H2O2,drought,cold and by the plant hormones ABA and salicylic acid.The tissue-specific expression pattern and OsVTE1-promoter GUS activity assay showed that OsVTE1 was mainly expressed in the leaf,and also could be detected in the root,stem and panicle.Compared with control plants,transgenic plants with OsVTE1 RNA interference(OsVTE1-RNAi) were more sensitive to salt stress whereas,in contrast,transgenic plants overexpressing OsVTE1(OsVTE1-OX) showed higher tolerance to salt stress.The DAB in vivo staining showed that OsVTE1-OX plants accumulated less H2O2 than did control plants.展开更多
基金supported by E-conomic Forest Germplasm Improvement and Com-prehensive Utilization of Resources of Hubei KeyLaboratories(20011BLKF238 and 2011BH0030)The Natural Science Foundation of China(30971974)Outstanding Young Project of HubeiEducational Office(Q20122708)~~
文摘Influence of high light stress on the photosynthesis of flag leaves of indica subspecies (cv. “Shanyou 63', sensitive to photoinhibition) and japonica subspecies (cv. “Wuyujing', resistant to photoinhibition) of rice ( Oryza sativa L.) was comparatively investigated. In both cultivars of rice, the excitation energy distribution between two photosystems was altered and the excitation energy transfer from light harvesting chlorophyll protein complexes to PSⅡ was inhibited by high light stress. These decreases were more pronounced in indica rice cultivar as compared to japonica one. The analysis of mild SDS_PAGE showed that in indica rice, high light stress almost disaggregated the trimer of light harvesting chlorophyll protein complexes of PSⅡ (LHC Ⅱ 1). The stress reduced the contents of internal antennae chlorophyll protein complexes of PSⅡ (CPa), light harvesting chlorophyll protein of PSⅠ (CPⅠa) and Chl a protein complex of PSⅠ reaction center (CPⅠ) as well as dimer of LHCⅡ (LHCⅡ 2) in indica rice. In japonica subspecies, however, high light stress depressed the contents of LHCⅡ 1, CPa and CPⅠa, but slightly impacted on CPⅠ content. Moreover, the increase in the contents of monomer of LHCⅡ by high light stress was found in both subspecies. In consistent with above results, analysis of polypeptide indicated that the amounts of 27 kD and 25 kD polypeptide of LHCⅡ in particular, as well as that of 21 kD polypeptide of CPⅠa were reduced by high light stress in both subspecies. It was found that, comparing with japonica rice, the stress pronouncedly diminished 43 kD and 47 kD proteins of CPa and 23 kD extrisic protein in indica rice.
基金Supported by National Natural Science Foundation (30070633 )National Science and Technology Supporting Project during the Eleventh Five-year Plan(2007BAD67B02)~~
文摘[Objective] The aim was to study the effects of drought stress on contents of endogenous hormones in leaves of different clones of Liriodendron chinense×L. tulipifera. Drought-resistant Liriodendron chinense×L. tulipifera clones NE25,NE78 and drought-sensitive Liriodendron chinense×L. tulipifera clones NE04,NE23 were selected as experimental materials to study the content changes of four kinds of endogenous hormones such as abscisic acid (ABA),indoleacetic acid (IAA),ribosylzeatin (ZR) and jasmonic acid (JA) in leaves of different clones under drought stress. [Result] Under drought stress,ABA was accumulated I leaves of different clones,however,the content changes in drought-resistant clones were not obvious; IAA content showed a decreasing trend,and the content changes n drought-resistant clones during later period of drought stress was decreased; JA content showed an increasing trend in leaves of drought-sensitive clones,indicating that drought-sensitive clones had to maintain higher contents of JA to resist drought stress. [Conclusion] The result of this study had provided scientific basis for the screening,planting and application of drougt-resistant clones of Liriodendron chinense×L. tulipifera.
文摘A pot experiment was conducted in lath house to study the response of six month-old seedlings of sour orange (Citrus aurantium L.) irrigated with salinity water (1, 2 or 4 ds/m) for four month. The seedling was sprayed with putrescine at 0, 150 or 300 mg/L concentrations for three times with month interval, for investigation the effects of putrrescine spraying on hormonal changes in sour orange seedlings under salt stress. One month after the last putrescine application, the leaves of the vegetative shoots were picked for endogenous plant hormone determination. The results indicate that increasing level of irrigation water salinity to 4 ds/m significantly increased ABA, Put and SA; whereas, decreasing IAA and GA in leave. Spraying vegetative canopy with putreseine at 300 mg/L increased 1AA, SA, ABA and Put, while decreased GA. It can be concluded that the adverse effects of high salinity irrigated water on endogenous plant hormone can be ameliorated, to some extent, by exogenous application of Put at 150 mg/L or 300 mg/L concentration.
基金supported by the National Basic Research Program of China (Grant No. 2006CB100102)National High-Tech Project (Grant No. 2006AA10Z18201)
文摘Tocopherols synthesized exclusively by photosynthetic organisms are major antioxidants in biomembranes.In plants,tocopherol cyclase(TC/VTE1) catalyzes the conversion of 2,3-dimethyl-5-phytyl-1,4-benzoquinone(DMPBQ) to γ-tocopherol.In the present study,OsVTE1,which encodes a rice tocopherol cyclase ortholog,was cloned and characterized.OsVTE1 was induced significantly by abiotic stresses such as high salt,H2O2,drought,cold and by the plant hormones ABA and salicylic acid.The tissue-specific expression pattern and OsVTE1-promoter GUS activity assay showed that OsVTE1 was mainly expressed in the leaf,and also could be detected in the root,stem and panicle.Compared with control plants,transgenic plants with OsVTE1 RNA interference(OsVTE1-RNAi) were more sensitive to salt stress whereas,in contrast,transgenic plants overexpressing OsVTE1(OsVTE1-OX) showed higher tolerance to salt stress.The DAB in vivo staining showed that OsVTE1-OX plants accumulated less H2O2 than did control plants.