State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, 85 Minglun Street, Kaifeng 475001, China.
State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, 85 Minglun Street, Kaifeng 475001, China.
Int J Mol Sci. 2021 Dec 24;23(1):194. doi: 10.3390/ijms23010194.
The chloroplast is a key organelle for photosynthesis and perceiving environmental information. GENOME UNCOUPLED 4 (GUN4) has been shown to be required for the regulation of both chlorophyll synthesis, reactive oxygen species (ROS) homeostasis and plastid retrograde signaling. In this study, we found that growth of the mutant was significantly improved under medium strong light (200 μmol photons ms) compared to normal light (100 μmol photons ms), in marked contrast to wild-type (WT). Further analysis revealed that GUN4 interacts with SIGNAL RECOGNITION PARTICLE 54 KDA SUBUNIT (SRP43) and SRP54. RNA-seq analysis indicated that the expression of genes for light signaling and the circadian clock is altered in compared with (WT). qPCR analysis confirmed that the expression of the clock genes (), (), () and () is significantly changed in the and mutants under normal and medium strong light conditions. These results suggest that GUN4 may coordinate the adaptation of plants to changing light conditions by regulating the biological clock, although it is not clear whether the effect is direct or indirect.
叶绿体是光合作用和感知环境信息的关键细胞器。已经表明，GENOME UNCOUPLED 4（GUN4）对于叶绿素合成、活性氧（ROS）稳态和质体逆行信号的调节都是必需的。在这项研究中，我们发现与正常光照（100 μmol 光子 ms）相比，突变体在中等强光（200 μmol 光子 ms）下的生长明显得到改善，与野生型（WT）形成鲜明对比。进一步的分析表明，GUN4 与 SIGNAL RECOGNITION PARTICLE 54 KDA SUBUNIT（SRP43）和 SRP54 相互作用。RNA-seq 分析表明，与 WT 相比，中强光下突变体的光信号和生物钟基因的表达发生改变。qPCR 分析证实，在正常和中等强光条件下，时钟基因 ()、()、()和 ()在突变体中的表达明显改变。这些结果表明，GUN4 可能通过调节生物钟来协调植物对不断变化的光照条件的适应，尽管尚不清楚这种影响是直接的还是间接的。
