National Key Laboratory for Tropical Crop Breeding, School of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), Key Laboratory of Biotechnology of Salt Tolerant Crops of Hainan Province, School of Tropical Agriculture and Forestry, Hainan University, Sanya, Hainan Province 572025, China.
Hainan Yazhou Bay Seed Laboratory, Sanya, Hainan Province 572025, China.
Plant Physiol. 2024 Mar 29;194(4):2724-2738. doi: 10.1093/plphys/kiae009.
Global warming is an adverse environmental factor that threatens crop yields and food security. 2C-type protein phosphatases (PP2Cs), as core protein phosphatase components, play important roles in plant hormone signaling to cope with various environmental stresses. However, the function and underlying mechanism of PP2Cs in the heat stress response remain elusive in tropical crops. Here, we report that MePP2C1 negatively regulated thermotolerance in cassava (Manihot esculenta Crantz), accompanied by the modulation of reactive oxygen species (ROS) accumulation and the underlying antioxidant enzyme activities of catalase (CAT) and ascorbate peroxidase (APX). Further investigation found that MePP2C1 directly interacted with and dephosphorylated MeCAT1 and MeAPX2 at serine (S) 112 and S160 residues, respectively. Moreover, in vitro and in vivo assays showed that protein phosphorylation of MeCAT1S112 and MeAPX2S160 was essential for their enzyme activities, and MePP2C1 negatively regulated thermotolerance and redox homeostasis by dephosphorylating MeCAT1S112 and MeAPX2S160. Taken together, this study illustrates the direct relationship between MePP2C1-mediated protein dephosphorylation of MeCAT1 and MeAPX2 and ROS accumulation in thermotolerance to provide insights for adapting to global warming via fine-tuning thermotolerance of the tropical crop cassava.
全球变暖是一种不利的环境因素，威胁着作物产量和粮食安全。2C 型蛋白磷酸酶（PP2Cs）作为核心蛋白磷酸酶成分，在植物激素信号转导中发挥重要作用，以应对各种环境胁迫。然而，PP2Cs 在热带作物热应激响应中的功能和潜在机制仍不清楚。在这里，我们报道 MePP2C1 负调控木薯（Manihot esculenta Crantz）的耐热性，伴随着活性氧（ROS）积累的调节和过氧化氢酶（CAT）和抗坏血酸过氧化物酶（APX）的潜在抗氧化酶活性。进一步的研究发现，MePP2C1 可直接与 MeCAT1 和 MeAPX2 相互作用，并使它们在丝氨酸（S）112 和 S160 残基上发生去磷酸化。此外，体外和体内试验表明，MeCAT1S112 和 MeAPX2S160 的蛋白磷酸化对其酶活性至关重要，而 MePP2C1 通过去磷酸化 MeCAT1S112 和 MeAPX2S160 负调控耐热性和氧化还原稳态。综上所述，本研究说明了 MePP2C1 介导的 MeCAT1 和 MeAPX2 的蛋白去磷酸化与耐热性中 ROS 积累之间的直接关系，为通过微调热带作物木薯的耐热性来适应全球变暖提供了见解。
