National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 200032, Shanghai, China.
State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China.
Nat Commun. 2023 Jul 24;14(1):4441. doi: 10.1038/s41467-023-40176-2.
Recurrent heat stress and pathogen invasion seriously threaten crop production, and abiotic stress often antagonizes biotic stress response against pathogens. However, the molecular mechanisms of trade-offs between thermotolerance and defense remain obscure. Here, we identify a rice thermo-sensitive mutant that displays a defect in floret development under high temperature with a mutation in SUPPRESSOR OF GENE SILENCING 3a (OsSGS3a). OsSGS3a interacts with its homolog OsSGS3b and modulates the biogenesis of trans-acting small interfering RNA (tasiRNA) targeting AUXIN RESPONSE FACTORS (ARFs). We find that OsSGS3a/b positively, while OsARF3a/b and OsARF3la/lb negatively modulate thermotolerance. Moreover, OsSGS3a negatively, while OsARF3a/b and OsARF3la/lb positively regulate disease resistance to the bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo) and the fungal pathogen Magnaporthe oryzae (M. oryzae). Taken together, our study uncovers a previously unknown trade-off mechanism that regulates distinct immunity and thermotolerance through the OsSGS3-tasiRNA-OsARF3 module, highlighting the regulation of abiotic-biotic stress response trade-off in plants.
反复的热应激和病原体入侵严重威胁着作物的生产，非生物胁迫通常会拮抗生物胁迫对病原体的反应。然而，耐热性和防御之间权衡的分子机制仍不清楚。在这里，我们鉴定了一个水稻热敏突变体，该突变体在高温下小花发育缺陷，突变发生在 SUPPRESSOR OF GENE SILENCING 3a（OsSGS3a）。OsSGS3a 与同源物 OsSGS3b 相互作用，并调节靶向 AUXIN RESPONSE FACTORS（ARFs）的转座小干扰 RNA（tasiRNA）的生物发生。我们发现 OsSGS3a/b 正向，而 OsARF3a/b 和 OsARF3la/lb 负向调节耐热性。此外，OsSGS3a 负向，而 OsARF3a/b 和 OsARF3la/lb 正向调节对细菌病原体稻黄单胞菌 pv. （Xoo）和真菌病原体稻瘟病菌（M. oryzae）的抗病性。总之，我们的研究揭示了一个以前未知的权衡机制，该机制通过 OsSGS3-tasiRNA-OsARF3 模块调节不同的免疫和耐热性，突出了植物中非生物生物胁迫反应权衡的调节。
