Abstract

The effect of drought on the morphophysiological, biochemical, and molecular genetic parameters of plants Sedobassia sedoides (Pall.) Freitag & G. Kadereit with an intermediate C₃–C₄-type of photosynthesis and Bassia prostrata (L.) A.J. Scott with a C₄-NADP type of photosynthesis grown at different temperatures (25 and 30°C) was studied. A decrease in the biomass, water content, and effective quantum yield (Φ_PSII) of PSII, as well as an increase in the expression of the psbA gene encoding the PSII D1 protein under the action of drought, was observed in both species regardless of the growing temperature. Both species showed a decrease in the content of photosynthetic enzymes ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and phosphoenolpyruvate carboxylase (PEPC) under drought conditions at 25°С, which was accompanied by a significant increase in the expression of the rbcL and PPDK genes in S. sedoides. Acclimation of S. sedoides plants to elevated temperatures led to an increase in the activity of cyclic electron transport around PSI, to mitigation of the negative effect of drought on the light reactions of photosynthesis (reduction in NPQ) and the content of the PEPC enzyme, as well as to a shift in the ionic balance caused by a decrease in the potassium content. B. prostrata showed greater drought resistance and was characterized by greater thermolability of photosynthetic enzymes, changes in the content and ratio of which allowed this species to maintain growth in drought conditions at different temperatures.

中文翻译：

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高温驯化对不同光合作用物种耐旱机制的影响：Sedobassia sedoides (C3–C4) 和 Bassia prostrata (C4-NADP)

摘要

干旱对具有中间 C ₃ –C _{4型光合作用的植物}Sedobassia sedoides (Pall.) Freitag & G. Kadereit 和具有中间型光合作用的Bassia prostrata (L.) AJ Scott的形态生理、生化和分子遗传参数的影响研究了在不同温度（25和30°C）下生长的C _{4 -NADP类型的光合作用。PSII 的生物量、含水量和有效量子产率 (Φ PSII} )降低，以及 psbA 表达增加无论生长温度如何，在干旱作用下，在这两个物种中都观察到编码 PSII D1 蛋白的基因。在 25°С 干旱条件下，这两个物种均表现出光合酶核酮糖-1,5-二磷酸羧化酶/加氧酶 (Rubisco) 和磷酸烯醇丙酮酸羧化酶 (PEPC) 的含量下降，同时伴随着S. sedoides中的rbcL和PPDK基因。S. sedoides的驯化将植物置于高温下会导致 PSI 周围循环电子传递活性的增加，减轻干旱对光合作用光反应（NPQ 减少）和 PEPC 酶含量的负面影响，以及钾含量减少导致离子平衡发生变化。B. prostrata表现出较强的抗旱性，其特点是光合酶具有较高的热稳定性，其含量和比例的变化使得该物种能够在不同温度的干旱条件下保持生长。