To explore the differences of sensitivities to chilling and strong light in indica and japonica rice (Oryza sativa L), the changes in unsaturation of thylakoid membrane lipids and xanthophyll cycle were studied under ...To explore the differences of sensitivities to chilling and strong light in indica and japonica rice (Oryza sativa L), the changes in unsaturation of thylakoid membrane lipids and xanthophyll cycle were studied under chilling condition and strong light. The contents of unsaturated fatty acids of thylakoid membrane lipids decreased and that of the saturated ones increased with the time of chilling and strong light treatment, resulting in the reduction of the index of unsaturation of fatty acids (IUFA). The activity of violaxanthin deepoxidase (VDE), a key enzyme of xanthophyll cycle, also reduced. The content of violaxanthin (V) increased, and the contents of antheraxanthin (A) and zeaxanthin M decreased, the ratio of (A+Z)/ (A+Z+V) decreased correspondingly. Arrhenius analysis showed that VDE was sensitive to both chilling and unsaturation level of thylakoid membrane lipids. Correlation analysis showed that there was distinctly positive relationships between IUFA of thylakoid membrane lipids and the activity of VDE, Fv/Fm, and D, protein content. Lower IUFA values, less fluidity and stability of thylakoid membrane lipids, lower VDE activity and (A+Z)/(A+Z+V) ratio were found in indica rice cv. Shanyou 63 than in japonica rice cv. 9516 under chilling and strong light.展开更多
Wheat(Triticum aestivum L.) lines T1, T4, and T6 were genetically modified to increase glycine betaine(GB) synthesis by introduction of the BADH(betaine aldehyde dehydrogenase, BADH)gene from mountain spinach(Atriplex...Wheat(Triticum aestivum L.) lines T1, T4, and T6 were genetically modified to increase glycine betaine(GB) synthesis by introduction of the BADH(betaine aldehyde dehydrogenase, BADH)gene from mountain spinach(Atriplex hortensis L.). These transgenic lines and WT of wheat(T. aestivum L.) were used to study the effect of increased GB synthesis on wheat tolerance to salt stress. Salt stress due to 200 mmol L-1Na Cl impaired the photosynthesis of the four wheat lines, as indicated by declines in net photosynthetic rate(Pn), stomatal conductance(Gs),maximum photochemical efficiency of PSII(Fv/Fm), and actual photochemical efficiency of PSII(ФPSII) and an increase in intercellular CO2concentration(Ci). In comparison with WT, the effect of salinity on the three transgenic lines was mild. Salt stress caused disadvantageous changes in lipids and their fatty acid compositions in the thylakoid membrane of the transgenic lines and WT. Under salt stress, the three transgenic lines showed slightly higher chlorophyll and carotenoid contents and higher Hill reaction activities and Ca2+-ATPase activity than WT. All the results suggest that overaccumulation of GB resulting from introduction of the BADH gene can enhance the salt tolerance of transgenic plants, especially in the protection of the components and function of thylakoid membranes, thereby making photosynthesis better. Changes in lipids and fatty acid compositions in the thylakoid membrane may be involved in the increased salt stress tolerance of the transgenic lines.展开更多
The chloroplast NAD(P)H dehydrogenase(NDH)complex,as one of the most important photosynthesis protein complexes in thylakoid membrane,is involved in photosystem I(PSI)cyclic electron transport(CEF).Under abiotic envir...The chloroplast NAD(P)H dehydrogenase(NDH)complex,as one of the most important photosynthesis protein complexes in thylakoid membrane,is involved in photosystem I(PSI)cyclic electron transport(CEF).Under abiotic environmental stress,the photosynthetic apparatus is susceptible to the damage caused by the strong light illumination.However,the enhancement of NDHdependent CEF could facilitate the alleviation of the damage to the photosynthetic apparatus.The NdhB subunit encoded by chloroplast genome is one of most important subunits of NDH complex and consists of 510 amino acids.Here,according to cloning ndhB from Melrose(cultivated soybean),ACC547(wild salt-tolerant soybean),S113-6 and S111-9(hybrid descendant),based on the comparison and analysis of the sequences of NdhB subunits,we found that there is a novel thylakoid transit peptide of NdhB subunit in S111-9.In addition,crosslink immunoprecipitation,immunogold labeling and co-expression of GFP fusion protein indicated that the novel thylakoid transit peptide is favorable to the expression and localization of NdhB subunit in chloroplast.Therefore,we suggest that this novel thylakoid transit peptide plays the same role as chaperonin and contributes to facilitating the expression and localization of NdhB subunit.展开更多
文摘To explore the differences of sensitivities to chilling and strong light in indica and japonica rice (Oryza sativa L), the changes in unsaturation of thylakoid membrane lipids and xanthophyll cycle were studied under chilling condition and strong light. The contents of unsaturated fatty acids of thylakoid membrane lipids decreased and that of the saturated ones increased with the time of chilling and strong light treatment, resulting in the reduction of the index of unsaturation of fatty acids (IUFA). The activity of violaxanthin deepoxidase (VDE), a key enzyme of xanthophyll cycle, also reduced. The content of violaxanthin (V) increased, and the contents of antheraxanthin (A) and zeaxanthin M decreased, the ratio of (A+Z)/ (A+Z+V) decreased correspondingly. Arrhenius analysis showed that VDE was sensitive to both chilling and unsaturation level of thylakoid membrane lipids. Correlation analysis showed that there was distinctly positive relationships between IUFA of thylakoid membrane lipids and the activity of VDE, Fv/Fm, and D, protein content. Lower IUFA values, less fluidity and stability of thylakoid membrane lipids, lower VDE activity and (A+Z)/(A+Z+V) ratio were found in indica rice cv. Shanyou 63 than in japonica rice cv. 9516 under chilling and strong light.
基金supported by National Natural Science Foundation of China (No. 31370304)the Opening Foundation of the State Key Laboratory ofCrop Biology (No 2013KF01)funded by the Education Department of Henan Province (No. 14A180036)
文摘Wheat(Triticum aestivum L.) lines T1, T4, and T6 were genetically modified to increase glycine betaine(GB) synthesis by introduction of the BADH(betaine aldehyde dehydrogenase, BADH)gene from mountain spinach(Atriplex hortensis L.). These transgenic lines and WT of wheat(T. aestivum L.) were used to study the effect of increased GB synthesis on wheat tolerance to salt stress. Salt stress due to 200 mmol L-1Na Cl impaired the photosynthesis of the four wheat lines, as indicated by declines in net photosynthetic rate(Pn), stomatal conductance(Gs),maximum photochemical efficiency of PSII(Fv/Fm), and actual photochemical efficiency of PSII(ФPSII) and an increase in intercellular CO2concentration(Ci). In comparison with WT, the effect of salinity on the three transgenic lines was mild. Salt stress caused disadvantageous changes in lipids and their fatty acid compositions in the thylakoid membrane of the transgenic lines and WT. Under salt stress, the three transgenic lines showed slightly higher chlorophyll and carotenoid contents and higher Hill reaction activities and Ca2+-ATPase activity than WT. All the results suggest that overaccumulation of GB resulting from introduction of the BADH gene can enhance the salt tolerance of transgenic plants, especially in the protection of the components and function of thylakoid membranes, thereby making photosynthesis better. Changes in lipids and fatty acid compositions in the thylakoid membrane may be involved in the increased salt stress tolerance of the transgenic lines.
基金This work was supported by the National Natural Science Foundation of China(31801273)the Zhejiang A&F University Scientific Research and Development Fund Project(2018FR049)+1 种基金the Department of Science and Technology of Ningbo(DSTNB,Project No.2019C10008)the China Postdoctoral Foundation(2016M591984).
文摘The chloroplast NAD(P)H dehydrogenase(NDH)complex,as one of the most important photosynthesis protein complexes in thylakoid membrane,is involved in photosystem I(PSI)cyclic electron transport(CEF).Under abiotic environmental stress,the photosynthetic apparatus is susceptible to the damage caused by the strong light illumination.However,the enhancement of NDHdependent CEF could facilitate the alleviation of the damage to the photosynthetic apparatus.The NdhB subunit encoded by chloroplast genome is one of most important subunits of NDH complex and consists of 510 amino acids.Here,according to cloning ndhB from Melrose(cultivated soybean),ACC547(wild salt-tolerant soybean),S113-6 and S111-9(hybrid descendant),based on the comparison and analysis of the sequences of NdhB subunits,we found that there is a novel thylakoid transit peptide of NdhB subunit in S111-9.In addition,crosslink immunoprecipitation,immunogold labeling and co-expression of GFP fusion protein indicated that the novel thylakoid transit peptide is favorable to the expression and localization of NdhB subunit in chloroplast.Therefore,we suggest that this novel thylakoid transit peptide plays the same role as chaperonin and contributes to facilitating the expression and localization of NdhB subunit.
