Institute of Basic Biological Problems, Russian Academy of Sciences, Institutskaya Street 2, Pushchino, Moscow Region 142290, Russia.
K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow 127276, Russia.
Biochim Biophys Acta Bioenerg. 2021 Aug 1;1862(8):148445. doi: 10.1016/j.bbabio.2021.148445. Epub 2021 Apr 30.
The effects of high-intensity light (HIL, 4 and 24 h) and UV-B (1 h) on the net photosynthesis rate, activity of photosystem II (PSII), content of photosynthetic pigments, anthocyanin and UV-absorbing pigments as well as the expression of certain light-responsive genes (HY5,CAB1) chalcone synthase (CHS) and main antioxidants enzyme genes (APX1, GPX and GR) in the leaves of phyB and phyA mutant A. thaliana plants were studied. Both UV-B and 4 and 24 h HIL decreased the PSII maximum quantum yield (F/F), PSII performance index (PI), photosynthesis and respiration rates in plants. Moreover, all stress treatments increased the dissipation of the absorbed energy (DI/RC) as well as the flux of absorbed energy per RC (ABS/RC). The maximal changes in photosynthesis and chlorophyll fluorescence parameters were observed in the phyB mutant. The WT and the phyA mutant showed similar responses. In addition, the phyB mutant exhibited decreases in the expression of genes encoding enzyme CHS, the transcription factor HY5 and the antioxidant enzymes APX1 and GPX. One of the possible mechanisms protecting the photosynthetic apparatus from light excess or UV radiation is the elevated content of various pigments that can act as antioxidants or optical filters. We assume that the greater decrease in photosynthetic activity in the phyB mutant under HIL and UV-B conditions was due to the decreased content of carotenoids and UV-absorbing pigments in this mutant.
研究了高强度光（HIL，4 和 24 小时）和 UV-B（1 小时）对 phyB 和 phyA 突变体拟南芥叶片净光合速率、光合系统 II（PSII）活性、光合色素、花青素和 UV 吸收色素含量、某些光响应基因（HY5、CAB1）、查尔酮合酶（CHS）和主要抗氧化酶基因（APX1、GPX 和 GR）表达的影响。UV-B 和 4 和 24 小时 HIL 均降低了 PSII 最大光量子产量（F/F）、PSII 性能指数（PI）、植物光合作用和呼吸速率。此外，所有胁迫处理均增加了吸收能量的耗散（DI/RC）以及 RC 每吸收能量的通量（ABS/RC）。光合作用和叶绿素荧光参数的最大变化发生在 phyB 突变体中。WT 和 phyA 突变体表现出相似的反应。此外，phyB 突变体表现出编码酶 CHS、转录因子 HY5 和抗氧化酶 APX1 和 GPX 的基因表达下降。一种可能的机制是通过增加各种可以作为抗氧化剂或光学过滤器的色素来保护光合作用器官免受光过量或 UV 辐射的伤害。我们假设 phyB 突变体在 HIL 和 UV-B 条件下光合作用活性下降更大，是由于该突变体中类胡萝卜素和 UV 吸收色素含量降低所致。
