Jindal Sunita, Kerchev Pavel, Berka Miroslav, Černý Martin, Botta Halidev Krishna, Laxmi Ashverya, Brzobohatý Břetislav
Department of Molecular Biology and Radiobiology, Mendel University in Brno, Brno, Czechia.
National Institute of Plant Genome Research, New Delhi, India.
Front Plant Sci. 2022 Sep 23;13:968139. doi: 10.3389/fpls.2022.968139. eCollection 2022.
Besides the long-standing role of cytokinins (CKs) as growth regulators, their current positioning at the interface of development and stress responses is coming into recognition. The current evidence suggests the notion that CKs are involved in heat stress response (HSR), however, the role of CK signaling components is still elusive. In this study, we have identified a role of the CK signaling components type-A Arabidopsis response regulators (ARRs) in HSR in Arabidopsis. The mutants of multiple type-A genes exhibit improved basal and acquired thermotolerance and, altered response to oxidative stress in our physiological analyses. Through proteomics profiling, we show that the type-A mutants experience a 'stress-primed' state enabling them to respond more efficiently upon exposure to real stress stimuli. A substantial number of proteins that are involved in the heat-acclimatization process such as the proteins related to cellular redox status and heat shock, are already altered in the type-A mutants without a prior exposure to stress conditions. The metabolomics analyses further reveal that the mutants accumulate higher amounts of α-and γ-tocopherols, which are important antioxidants for protection against oxidative damage. Collectively, our results suggest that the type-A ARRs play an important role in heat stress response by affecting the redox homeostasis in Arabidopsis.
除了细胞分裂素（CKs）长期以来作为生长调节剂的作用外，它们目前在发育与应激反应界面的定位正逐渐得到认可。目前的证据表明CKs参与热应激反应（HSR），然而，CK信号成分的作用仍不明确。在本研究中，我们确定了拟南芥中CK信号成分A型拟南芥反应调节因子（ARRs）在HSR中的作用。多个A型基因的突变体在我们的生理分析中表现出增强的基础耐热性和获得性耐热性，以及对氧化应激的反应改变。通过蛋白质组学分析，我们表明A型突变体处于一种“应激预适应”状态，使它们在暴露于真实应激刺激时能够更有效地做出反应。大量参与热适应过程的蛋白质，如与细胞氧化还原状态和热休克相关的蛋白质，在A型突变体中已经发生改变，而无需事先暴露于应激条件下。代谢组学分析进一步揭示，突变体积累了更高量的α-和γ-生育酚，它们是防止氧化损伤的重要抗氧化剂。总体而言，我们的结果表明A型ARRs通过影响拟南芥中的氧化还原稳态在热应激反应中发挥重要作用。
