Abstract

Components of СО₂/Н₂О exchange (rates of apparent photosynthesis, transpiration, and dark respiration), as well as efficiency of photosystem I, growth rate, and proline content, were investigated in plants of the С₃ species (Atriplex verrucifera M. Bieb), two populations of the С₄ species (A. tatarica L.), and two populations of the intermediate С₃–С₄ species (Sedobassia sedoides (Pall.) Freitag & G. Kadereit), family Chenopodiaceae, in the course of adaptation to PEG-induced moderate osmotic stress (–0.4…–0.5 MPa). Two taken СО₂ concentrations (400 and 200 ppm) enabled the examination of stomatal and metabolic contribution to the formation of the mechanisms of drought tolerance and estimate sensitivity of stomata. Under moderate water deficit, the С₃ species showed drought tolerance and succulence and was notable for insensitive stomata. Examination of growth characteristics made it possible to reveal differences in productivity and tolerance between populations of the С₄ and С₃–С₄ species. In spite of a different nature of carbon-concentrating mechanism (aspartate in С₄ and photorespiratory in С₃–С₄), populations tolerant to water deficiency shared common features: less sensitive stomata and operation of the mechanism stabilizing water balance of the leaf cells probably due to proline and cyclic transport of electrons. Realization of such a strategy maintains coordination among parameters of СО₂/Н₂О exchange, which ensures a lower variability of dark respiration and a greater tolerance of plants to moderate osmotic stress. In nontolerant populations, adaptation mainly depends on stomatal closure, which probably results in upsetting the balance among parameters of СО₂/Н₂О exchange.

中文翻译：

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СО2 /Н2О交换组分对不同光合作用类型藜科藜科植物旱生植物适应干旱过程的比较贡献

摘要

СО的部件₂ /Н ₂ О交换，以及光系统I，生长速率，和脯氨酸含量的效率（表观光合作用，蒸腾作用，和暗呼吸速率），分别在С的植物研究₃种（滨藜疣中号。BIEB），则С的两个群体₄种（A.鞑靼L.），和中间С的两个群体₃ -С ₄种（Sedobassia sedoides（帕尔。）Freitag的＆G. Kadereit），家庭藜科，在适应PEG诱导的中等渗透压力（–0.4…–0.5 MPa）的过程。两所СО ₂浓度（400和200 ppm）能够检查气孔和代谢对干旱耐受机制形成的影响，并估计气孔的敏感性。在适度水分亏缺的С ₃种表现出耐旱性和肉质，是值得注意的是不敏感的气孔。的生长特性检验做出能够展现了С的人口之间在生产力和包容差异₄和С ₃ -С ₄种。尽管具有不同的性质的碳浓缩机制（天冬氨酸在С ₄和光呼吸中С ₃ -С ₄），耐缺水的种群共有一些共同特征：气孔敏感性较低以及稳定叶细胞水分平衡的机制可能是由于脯氨酸和电子的循环运输所致。这种策略的实现保持СО的参数之间的协调₂ /Н ₂ О交换，保证暗呼吸的低可变性和植物的更大的宽容，中度渗透胁迫。在nontolerant人群，适应主要取决于气孔关闭，这可能导致扰乱СО的参数之间的平衡₂ /Н ₂ О交流。