Department of Plant Anatomy and Cytology, Institute of Experimental Plant Biology and Biotechnology, Faculty of Biology, University of Warsaw, I. Miecznikowa 1, 02-096 Warsaw, Poland.
Department of Metabolic Regulation, Institute of Biochemistry, Faculty of Biology, University of Warsaw, I. Miecznikowa 1, 02-096 Warsaw, Poland.
Int J Mol Sci. 2020 Dec 28;22(1):221. doi: 10.3390/ijms22010221.
The origin of chlorophyll deficiency is a mutation () in chlorophyllide oxygenase (CAO), the enzyme responsible for Chl synthesis. Regulation of Chl synthesis is essential for understanding the mechanism of plant acclimation to various conditions. Therefore, the main aim of this study was to find the strategy in plants for compensation of low chlorophyll content by characterizing and comparing the performance and spectral properties of the photosynthetic apparatus related to the lipid and protein composition in four selected Arabidopsis mutants and two Arabidopsis ecotypes. Mutation in different loci of the CAO gene, ., NW41, , and , manifested itself in a distinct phenotype, pigment and photosynthetic protein composition. Changes in the CAO mRNA levels and chlorophyllide (Chlide ) content in ecotypes and mutants indicated their significant role in the adjustment mechanism of the photosynthetic apparatus to low-light conditions. Exposure of mutants with a lower chlorophyll content to short-term (1LL) and long-term low-light stress (10LL) enabled showing a shift in the structure of the PSI and PSII complexes via spectral analysis and the thylakoid composition studies. We demonstrated that both ecotypes, Col-1 and Ler-0, reacted to high-light (HL) conditions in a way remarkably resembling the response of mutants to normal (NL) conditions. We also presented possible ways of regulating the conversion of chlorophyll to depending on the type of light stress conditions.
叶绿素缺乏症的起源是叶绿素加氧酶（CAO）的突变（），CAO 是负责叶绿素合成的酶。对叶绿素合成的调控对于理解植物对各种条件的适应机制至关重要。因此，本研究的主要目的是通过表征和比较与脂质和蛋白质组成相关的光合作用器官在四个选定的拟南芥突变体和两个拟南芥生态型中的性能和光谱特性，找到植物补偿低叶绿素含量的策略。CAO 基因不同位点的突变，，，NW41，和，表现出明显的表型、色素和光合蛋白组成的差异。在生态型和突变体中 CAO mRNA 水平和叶绿素含量的变化表明它们在光合作用器官对低光照条件的调节机制中发挥着重要作用。对叶绿素含量较低的突变体进行短期（1LL）和长期低光照胁迫（10LL）的暴露，使我们能够通过光谱分析和类囊体组成研究显示 PSI 和 PSII 复合物结构的转变。我们证明，Col-1 和 Ler-0 这两个生态型对高光（HL）条件的反应方式与突变体对正常（NL）条件的反应方式非常相似。我们还提出了根据不同类型的光胁迫条件调节叶绿素转化为的可能方法。
