Comparative Analysis of Heat-Tolerant and Heat-Susceptible Rice Highlights the Role of OsNCED1 Gene in Heat Stress Tolerance.

Zhou H, Wang Y, Zhang Y, Xiao Y, Liu X, Deng H, Lu X, Tang W, Zhang G.

Plants (Basel). 2022 Apr 13;11(8):1062. doi: 10.3390/plants11081062.

Abstract

To elucidate the mechanism underlying the response of rice to heat stress (HS), the transcriptome profile of panicles was comparatively analyzed between the heat-tolerant line 252 (HTL252) and heat-susceptible line 082 (HSL082), two rice recombinant inbred lines (RILs). Our differentially expressed gene (DEG) analysis revealed that the DEGs are mainly associated with protein binding, catalysis, stress response, and cellular process. The MapMan analysis demonstrated that the heat-responsive (HR) genes for heat shock proteins, transcription factors, development, and phytohormones are specifically induced in HTL252 under HS. Based on the DEG analysis, the key gene OsNCED1 (Os02g0704000), which was induced under HS, was selected for further functional validation. Moreover, 9-cis-epoxycarotenoid dioxygenase (NCED) is a key rate-limiting enzyme in the ABA biosynthetic pathway. Overexpression of OsNCED1 improved the HS tolerance of rice at the heading and flowering stage. OsNCED1-overexpression plants exhibited significant increases in pollen viability, seed setting rate, superoxide dismutase (SOD) and peroxidase (POD) activities, while significantly lower electrolyte leakage and malondialdehyde (MDA) content relative to the wild type (WT). These results suggested that OsNCED1 overexpression can improve the heat tolerance of rice by enhancing the antioxidant capacity. Overall, this study lays a foundation for revealing the molecular regulatory mechanism underlying the response of rice to prolonged HS.

See https://pubmed.ncbi.nlm.nih.gov/35448790/

Figure 1

(A) Venn diagram of DEGs in HTL252 and HSL082 under HS. HTL252_up indicates the upregulated genes in HTL252, HSL082_up represents the upregulated genes in HSL082, HTL252_down indicates the downregulated genes in HTL252, and HSL082_down stands for the downregulated genes in HSL082. (B) Distribution of DEGs according to fold-changes F. Negative log base 2 changes in fold indicate repression, while positive values represent induction. Y-axis indicates the number of upregulated or downregulated DEGs. The part of Y-axis above 0 stands for upregulation, and that below 0 represents downregulation. X-axis indicates the range of variation of F.