Yudina Lyubov, Gromova Ekaterina, Grinberg Marina, Popova Alyona, Sukhova Ekaterina, Sukhov Vladimir
Department of Biophysics, N.I. Lobachevsky State University of Nizhny Novgorod, 603950 Nizhny Novgorod, Russia.
Plants (Basel). 2022 Feb 17;11(4):534. doi: 10.3390/plants11040534.
Local damage to plants can induce fast systemic physiological changes through generation and propagation of electrical signals. It is known that electrical signals influence numerous physiological processes including photosynthesis; an increased plant tolerance to actions of stressors is a result of these changes. It is probable that parameters of electrical signals and fast physiological changes induced by these signals can be modified by the long-term actions of stressors; however, this question has been little investigated. Our work was devoted to the investigation of the parameters of burning-induced electrical signals and their influence on photosynthesis under soil water shortage in pea seedlings. We showed that soil water shortage decreased the amplitudes of the burning-induced depolarization signals (variation potential) and the magnitudes of photosynthetic inactivation (decreasing photosynthetic CO assimilation and linear electron flow and increasing non-photochemical quenching of the chlorophyll fluorescence and cyclic electron flow around photosystem I) caused by these signals. Moreover, burning-induced hyperpolarization signals (maybe, system potentials) and increased photosynthetic CO assimilation could be observed under strong water shortage. It was shown that the electrical signal-induced increase of the leaf stomatal conductance was a potential mechanism for the burning-induced activation of photosynthetic CO assimilation under strong water shortage; this mechanism was not crucial for photosynthetic response under control conditions or weak water shortage. Thus, our results show that soil water shortage can strongly modify damage-induced electrical signals and fast physiological responses induced by these signals.
植物局部损伤可通过电信号的产生和传播诱导快速的系统生理变化。已知电信号会影响包括光合作用在内的众多生理过程；这些变化导致植物对应激源作用的耐受性增强。应激源的长期作用可能会改变电信号参数以及由这些信号诱导的快速生理变化；然而，这一问题鲜有研究。我们的工作致力于研究豌豆幼苗在土壤缺水情况下，燃烧诱导的电信号参数及其对光合作用的影响。我们发现，土壤缺水会降低燃烧诱导的去极化信号（变异电位）的幅度，以及由这些信号引起的光合失活程度（光合CO同化和线性电子流降低，叶绿素荧光的非光化学猝灭以及光系统I周围的循环电子流增加）。此外，在严重缺水情况下，可观察到燃烧诱导的超极化信号（可能是系统电位）以及光合CO同化增加。结果表明，电信号诱导的叶片气孔导度增加是严重缺水情况下燃烧诱导光合CO同化激活的潜在机制；该机制在对照条件或轻度缺水情况下对光合响应并不关键。因此，我们的结果表明，土壤缺水可强烈改变损伤诱导的电信号以及由这些信号诱导的快速生理反应。
