The study led by Dr. Xiangsong Chen (Wuhan University) and Dr. Haiya Cai (Hubei Academy of Agricultural Sciences) analyzed the transcriptomes of two rice cultivars, Nagina22 and 93-11, under high-temperature stress. It was found that the expression of JAZ genes specifically increased significantly in N22 at the early stage of heat stress, accompanied by a significant decrease in the expression of downstream response genes of the Jasmonic acid (JA) signaling pathway. Additionally, exogenous application of JA significantly reduced the heat tolerance of N22, indicating that the suppression of JA signaling at the early stage of heat stress may be one of the reasons for the high heat-tolerance of N22.
They further explored the reasons for the specific upregulation of JAZ genes in N22 under high-temperature stress from the perspective of epigenetic regulation. DNA methylation analysis revealed that during heat treatment, N22 exhibited more drastic whole-genome DNA methylation fluctuations, mainly manifested as genome-wide DNA demethylation at the early stage of heat stress, especially CHH demethylation, while the changes in 93-11 were very slight. The analysis found that MITEs transposons were significantly enriched in the regions of CHH demethylation, and the surrounding regions of the JAZ genes were rich in MITEs transposons, suggesting that that the DNA demethylation of MITEs transposons in N22 under heat stress might be the reason for the upregulated expression of JAZ genes. Given the widespread distribution of MITEs transposons in the genome, the findings of this study suggested that MITEs may regulate gene expression through their own DNA methylation modifications, thereby helping plants better adapt to environmental changes.
See the article:
Epigenetic regulation of Jasmonate ZIM-domain genes contributes to heat tolerance in the heat-tolerant rice cultivar Nagina 22
https://link.springer.com/article/10.1007/s42994-025-00229-0
