Sukhov Vladimir, Gaspirovich Vladimir, Mysyagin Sergey, Vodeneev Vladimir
Department of Biophysics, N.I. Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia.
Front Physiol. 2017 Sep 29;8:763. doi: 10.3389/fphys.2017.00763. eCollection 2017.
It is known that numerous stimuli induce electrical signals which can increase a plant's tolerance to stressors, including high temperature. However, the physiological role of local electrical responses (LERs), i.e., responses in the zone of stimulus action, in the plant's tolerance has not been sufficiently investigated. The aim of a current work is to analyze the connection between parameters of LERs with the thermal tolerance of photosynthetic processes in pea. Electrical activity and photosynthetic parameters in pea leaves were registered during transitions of air temperature in a measurement head (from 23 to 30°C, from 30 to 40°C, from 40 to 45°C, and from 45 to 23°C). This stepped heating decreased a photosynthetic assimilation of CO and induced generation of LERs in the heated leaf. Amplitudes of LERs, quantity of responses during the heating and the number of temperature transition, which induced the first generation of LERs, varied among different pea plants. Parameters of LERs were weakly connected with the photosynthetic assimilation of CO during the heating; however, a residual photosynthetic activity after a treatment by high temperatures increased with the growth of amplitudes and quantity of LERs and with lowering of the number of the heating transition, inducing the first electrical response. The effect was not connected with a photosynthetic activity before heating; similar dependences were also observed for effective and maximal quantum yields of photosystem II after heating. We believe that the observed effect can reflect a positive influence of LERs on the thermal tolerance of photosynthesis. It is possible that the process can participate in a plant's adaptation to stressors.
众所周知，多种刺激会诱发电信号，这些电信号可增强植物对包括高温在内的应激源的耐受性。然而，局部电反应（LERs），即刺激作用区域内的反应，在植物耐受性方面的生理作用尚未得到充分研究。当前这项工作的目的是分析豌豆中局部电反应参数与光合过程耐热性之间的联系。在测量头中的空气温度发生转变期间（从23℃升至30℃、从30℃升至40℃、从40℃升至45℃以及从45℃降至23℃），记录了豌豆叶片中的电活动和光合参数。这种阶梯式加热降低了CO的光合同化作用，并在受热叶片中诱发出局部电反应。不同豌豆植株的局部电反应幅度、加热过程中的反应数量以及诱发第一代局部电反应的温度转变次数各不相同。加热过程中局部电反应参数与CO的光合同化作用之间的联系较弱；然而，高温处理后的残余光合活性随着局部电反应幅度和数量的增加以及诱发首次电反应的加热转变次数的减少而增加。这种效应与加热前的光合活性无关；加热后光系统II的有效量子产率和最大量子产率也观察到了类似的相关性。我们认为，观察到的这种效应可能反映了局部电反应对光合作用耐热性的积极影响。该过程有可能参与植物对应激源的适应。
