Zhang Ya, Qiao Dan, Zhang Zhe, Li Yaping, Shi Shuqian, Yang Yingli
School of Life Science, College of Life Science, Northwest Normal University, Lanzhou, 730070 Gansu People's Republic of China.
Physiol Mol Biol Plants. 2024 Jan;30(1):123-136. doi: 10.1007/s12298-024-01413-0. Epub 2024 Feb 1.
This study aimed to explore the mechanism by which calcium (Ca) signal regulated carbohydrate metabolism and exogenous Ca alleviated salinity toxicity. Wheat seedlings were treated with sodium chloride (NaCl, 150 mM) alone or combined with 500 μM calcium chloride (CaCl), lanthanum chloride (LaCl) and/or ethylene glycol tetraacetic acid (EGTA) to primarily analyse carbohydrate starch and sucrose metabolism, as well as Ca signaling components. Treatment with NaCl, EGTA, or LaCl alone retarded wheat-seedling growth and decreased starch content accompanied by weakened ribulose-1,5-bisphosphate carboxylation/oxygenase (Rubisco) and Rubisco activase activities, as well as enhanced glyceraldehyde-3-phosphate dehydrogenase, phosphoglycerate kinase, alpha-amylase, and beta-amylase activities. However, it increased the sucrose level, up-regulated the sucrose phosphate synthase (SPS) and sucrose synthase (SuSy) activities and and expression together, but down-regulated the acid invertase (SA-Inv) and alkaline/neutral invertase (A/N-Inv) activities and and expression. Except for unchanged A/N-Inv activities and expression, adding CaCl effectively blocked the sodium salt-induced changes of these parameters, which was partially eliminated by EGTA or LaCl presence. Furthermore, NaCl treatment also significantly inhibited Ca-dependent protein kinases and Ca-ATPase activities and their gene expression in wheat leaves, which was effectively relieved by adding CaCl. Taken together, CaCl application effectively alleviated the sodium salt-induced retardation of wheat-seedling growth by enhancing starch anabolism and sucrose catabolism, and intracellular Ca signal regulated the enzyme activities and gene expression of starch and sucrose metabolism in the leaves of sodium salt-stressed wheat seedlings.
本研究旨在探究钙（Ca）信号调节碳水化合物代谢以及外源钙缓解盐胁迫毒性的机制。用氯化钠（NaCl，150 mM）单独处理或与500 μM氯化钙（CaCl）、氯化镧（LaCl）和/或乙二醇四乙酸（EGTA）联合处理小麦幼苗，以初步分析碳水化合物淀粉和蔗糖代谢以及钙信号成分。单独用NaCl、EGTA或LaCl处理会抑制小麦幼苗生长，降低淀粉含量，同时伴随1,5-二磷酸核酮糖羧化/加氧酶（Rubisco）和Rubisco活化酶活性减弱，以及甘油醛-3-磷酸脱氢酶、磷酸甘油酸激酶、α-淀粉酶和β-淀粉酶活性增强。然而，它会提高蔗糖水平，上调蔗糖磷酸合酶（SPS）和蔗糖合酶（SuSy）的活性及相关基因表达，但下调酸性转化酶（SA-Inv）和碱性/中性转化酶（A/N-Inv）的活性及相关基因表达。除A/N-Inv活性和相关基因表达不变外，添加CaCl有效阻断了钠盐诱导的这些参数变化，而EGTA或LaCl的存在可部分消除这种变化。此外，NaCl处理还显著抑制了小麦叶片中钙依赖性蛋白激酶和钙ATP酶的活性及其基因表达，添加CaCl可有效缓解这种抑制。综上所述，施加CaCl通过增强淀粉合成代谢和蔗糖分解代谢有效缓解了钠盐诱导的小麦幼苗生长迟缓，细胞内钙信号调节了盐胁迫下小麦幼苗叶片中淀粉和蔗糖代谢的酶活性及基因表达。
