Responses of Physiology,Photosynthesis and Related genes to Saline Stress in Cornus.hongkongensis subsp.tonkinensis
Responses of Physiology,Photosynthesis and Related genes to Saline Stress in Cornus.hongkongensis subsp.tonkinensis
Cornus.hongkongensis subsp.tonkinensis is a native evergreen species with high ornamental values for abundant variations in color of leaf,bract,fruit and the gesture of tree.To broaden its cultivation in coastal saline soil,salt damage and survival rate,physiology responses,photosynthetic performance and related genes were evaluated for annual seedlings exposed to 0.3%salt(ST)concentrations for 60 days.Syndromes of salt damage aggravated and survival rate descend with the prolonged stress duration;all stressed seedlings displayed salt damage,and 58.3%survived finally.Under short-term saline stress(5 d),the marked increase in malondialdehyde(MDA)and relative electrical conductivity(REC),decreases in superoxide dismutase(SOD),photosynthetic rate(Pn),stomatal conductance(gs),and internal carbon dioxide concentration(Ci)were recorded.The stable leaf water use efficiency(WUE)and chlorophyll content were the positive physiological responses to ensure water balance and photosynthetic performance.Meantime,the expression level of genes related to photosystem II(psbA)and photorespiration(SGAT and GGAT)were upregulated,indicating the role of photorespiration in protecting photosynthesis from photoinhibition.After 30 days of stress,the significant increasing tends in malondialdehyde(MDA),relative electrical conductivity(REC),soluble sugar(SS),soluble protein(SP)and Ci,whereas the descending patterns in Pn,gs,WUE,the maximal photochemical efficiency of photosystem II(Fv/Fm),and potential activities of PSII(Fv/F0)occurred in salt-stressed seedlings,when compared with CK.Meanwhile,the expression levels of the genes related to photosynthesis(psbA and LFNR),photorespiratory pathway(GGAT and GLYK),and calvin cycle(PGK)significantly dropped,leading to photoinhibition and worse photosynthetic performance.Hence,these results provide a framework for better understanding the photosynthetic responses C.tonkinensis to salt stress.
Jia-Qiu Yuan;Qiang Lu;Ling Yang;Da-Wei Sun;Xiang-Xiang Fu;
College of Forestry,Nanjing Forestry University,210037 Nanjing,China;Co-Innovation Center for Sustainable Forestry in Southern China,Nanjing Forestry University,210037 Nanjing,China##College of Forestry,Nanjing Forestry University,210037 Nanjing,China;Co-Innovation Center for Sustainable Forestry in Southern China,Nanjing Forestry University,210037 Nanjing,China##College of Forestry,Nanjing Forestry University,210037 Nanjing,China;Co-Innovation Center for Sustainable Forestry in Southern China,Nanjing Forestry University,210037 Nanjing,China##College of Forestry,Nanjing Forestry University,210037 Nanjing,China;Co-Innovation Center for Sustainable Forestry in Southern China,Nanjing Forestry University,210037 Nanjing,China##College of Forestry,Nanjing Forestry University,210037 Nanjing,China;
Cornus.hongkongensis subsp.tonkinensis osmotic regulators photorespiration photosynthesis salinity tolerance
1004-1004 / 1
评论