Institute of Basic Biological Problems, FRC PSCBR RAS, Pushchino, Moscow Region 142290, Russia.
Federal State Budgetary Scientific Institution North Caucasian Regional Research Institute of Horticulture and Viticulture, Krasnodar 350072, Russia.
Biochim Biophys Acta Bioenerg. 2020 Nov 1;1861(11):148260. doi: 10.1016/j.bbabio.2020.148260. Epub 2020 Jul 14.
A comparative analysis of functional characteristics of the grapevine leaf photosynthetic apparatus (LPA) and corticular photosynthetic apparatus (CPA) in chlorenchyma tissues of first-year lignified vine was performed. Obtained results demonstrate significant differences between the functional properties of the CPA and the LPA. CPA contains an increased proportion (about 2/3) of Q-non-reducing centers of photosystem II (PSII) that is confirmed by elevated O-J phase in fluorescence kinetics, high PSIIβ content, and slower Q reoxidation. CPA and LPA use different strategies to utilize absorbed light energy and to protect itself against excessive light. CPA dissipates a significant proportion of absorbed light energy as heat (regulated and non-regulated dissipation), and only a smaller part of the excitation energy is used in the dark stages of photosynthesis. The rate constant of photoinhibition and fluorescence quenching due to photoinhibition in CPA is almost three times higher than in LPA, while high-energy state fluorescence quenching value is twice lower. The saturation of vine chlorenchyma tissue with water increases the CPA tolerance to photoinhibition and promotes the ability to restore the photosynthetic activity after photoinhibition. The electron microscopy analysis confirmed the presence of intact plastids in vine chlorenchyma tissue, the interior space of plastids is filled with large starch grains while bands of stacked thylakoid membranes are mainly localized on the periphery. Analyzes showed that corticular plastids are specialized organelles combining features of chloroplasts, amyloplasts and gerontoplasts. Distinct structural organization of photosynthetic membranes and microenvironment predetermine distinctive functional properties of CPA.
对木质一年生葡萄藤叶肉组织中叶片光合器官（LPA）和皮层光合器官（CPA）的功能特性进行了比较分析。结果表明，CPA 和 LPA 的功能特性存在显著差异。CPA 含有更多比例（约 2/3）的 PSII Q-非还原中心，这一点通过荧光动力学中的 O-J 相升高、PSIIβ 含量高和 Q 再氧化较慢得到证实。CPA 和 LPA 利用不同的策略来利用吸收的光能并保护自身免受过量光的伤害。CPA 将相当一部分吸收的光能以热量的形式耗散（调节和非调节耗散），只有较小部分的激发能用于光合作用的暗反应阶段。CPA 中由于光抑制导致的光抑制的光致猝灭和荧光猝灭的速率常数比 LPA 高近 3 倍，而高能态荧光猝灭值则低 2 倍。水对葡萄藤叶肉组织的饱和增加了 CPA 对光抑制的耐受性，并促进了光抑制后光合活性的恢复能力。电子显微镜分析证实了葡萄藤叶肉组织中存在完整的质体，质体的内部空间充满了大的淀粉粒，而堆叠的类囊体膜带主要定位于外围。分析表明，皮层质体是一种特殊的细胞器，结合了叶绿体、淀粉体和衰老质体的特征。光合膜的独特结构组织和微环境决定了 CPA 的独特功能特性。
