The Laboratory of Seed Science and Technology, Guangdong Key Laboratory of Plant Molecular Breeding, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, 510642, Guangzhou, China.
Nat Commun. 2023 Apr 21;14(1):2296. doi: 10.1038/s41467-023-38085-5.
Submergence stress represents a major obstacle limiting the application of direct seeding in rice cultivation. Under flooding conditions, coleoptile elongation can function as an escape strategy that contributes to submergence tolerance during seed germination in rice; however, the underlying molecular bases have yet to be fully determined. Herein, we report that natural variation of rice coleoptile length subjected to submergence is determined by the glucosyltransferase encoding gene OsUGT75A. OsUGT75A regulates coleoptile length via decreasing free abscisic acid (ABA) and jasmonic acid (JA) levels by promoting glycosylation of these two phytohormones under submergence. Moreover, we find that OsUGT75A accelerates coleoptile length through mediating the interactions between JASMONATE ZIMDOMAIN (OsJAZ) and ABSCISIC ACID-INSENSITIVE (OsABI) proteins. Last, we reveal the origin of the haplotype that contributes to coleoptile length in response to submergence and transferring this haplotype to indica rice can enhance coleoptile length in submergence conditions. Thus, we propose that OsUGT75A is a useful target in breeding of rice varieties suitable for direct seeding cultivation.
淹水胁迫是限制水稻直播应用的主要障碍。在淹水条件下，胚芽鞘伸长可以作为一种逃避策略，有助于水稻种子萌发时的耐淹；然而，其潜在的分子基础尚未完全确定。在此，我们报道了水稻胚芽鞘长度的自然变异受葡萄糖基转移酶编码基因 OsUGT75A 的控制。OsUGT75A 通过促进这两种激素的糖基化，降低游离脱落酸（ABA）和茉莉酸（JA）水平，从而调节胚芽鞘长度。此外，我们发现 OsUGT75A 通过介导 JASMONATE ZIMDOMAIN（OsJAZ）和 ABSCISIC ACID-INSENSITIVE（OsABI）蛋白之间的相互作用，加速胚芽鞘伸长。最后，我们揭示了导致胚芽鞘长度对淹水响应的单倍型的起源，并将该单倍型转移到籼稻中，可以增强籼稻在淹水条件下的胚芽鞘伸长。因此，我们认为 OsUGT75A 是培育适合直播栽培的水稻品种的一个有用目标。
