Recently, a research team led by Professor Qian Qian from China National Rice Research Institute (CNRRI) of Chinese Academy of Agricultural Sciences (CAAS) reported the relationship between genomic stability and reactive oxygen species (ROS) accumulation. This study has been published in New Phytologist, enhancing the understanding of the regulatory mechanism of the response to HLHT stress in higher plants.

High light and high temperature (HLHT) stress may become more frequent and severe as the climate changes, affecting crop growth and resulting in reduced production. Researchers screened a rice mutant library using HLHT conditions and isolated a HLHT-sensitive mutant, local lesions 1 (ls1), which showed decreased pigment contents, defective stomata and chloroplasts, and a local lesions phenotype under HLHT. Then, LS1 was characterized and cloned by map-based cloning and genetic complementation. LS1 encodes the A subunit of the RNase H2 complex (RNASEH2A). TUNEL and comet assays indicated that mutation of LS1 led to severe DNA damage under HLHT stress. Furthermore, researchers found excessive reactive oxygen species (ROS) accumulation in the ls1 mutant under HLHT stress. Exogenous antioxidants eased the local lesions phenotype of the ls1 mutant under HLHT. DNA damage caused by HLHT stress induces ROS accumulation, which causes the injury and apoptosis of leaf cells in the ls1 mutant.

This study was supported by The National Natural Science Foundation of China (Grant Nos. 31601284, 31661143006, 91735303); Zhejiang Province Outstanding Youth Fund (Grant No. LR16C130001)；The Transgenic Plant Research and Commercialization Project of the Ministry of Agriculture of China (Grant No. 2016ZX08001003-002); The “Collaborative Innovation Project” and“Science and technology innovation project” of the Chinese Academy of Agricultural Sciences. PhD. student Qiu Zhennan and Dr. Zhu Li are co-first authors of the study, and Prof. Qian Qian is the corresponding author. More details are available on the link below:

https://nph.onlinelibrary.wiley.com/doi/10.1111/nph.15597