How rice defeats the floodwaters Deepwater rice varieties grow taller when flooded, in a growth response driven by the plant hormones gibberellin and ethylene. This keeps the leaves above the water. Kuroha et al. identified the genes underlying this phenotype, which encode a component of the gibberellin biosynthetic pathway and its regulatory ethylene-responsive transcription factor. This genetic relay drives growth of the plant stem internodes in response to flooding. Modern cultivated deepwater rice, which has been domesticated for adaptation to the monsoon season of Bangladesh, emerged from the genetic variation found in wild rice strains over a broader geographic region. Science, this issue p. 181 Ethylene-inducible activation of gibberellin biosynthesis helps rice survive long periods of submersion in flooded plots. Most plants do poorly when flooded. Certain rice varieties, known as deepwater rice, survive periodic flooding and consequent oxygen deficiency by activating internode growth of stems to keep above the water. Here, we identify the gibberellin biosynthesis gene, SD1 (SEMIDWARF1), whose loss-of-function allele catapulted the rice Green Revolution, as being responsible for submergence-induced internode elongation. When submerged, plants carrying the deepwater rice–specific SD1 haplotype amplify a signaling relay in which the SD1 gene is transcriptionally activated by an ethylene-responsive transcription factor, OsEIL1a. The SD1 protein directs increased synthesis of gibberellins, largely GA4, which promote internode elongation. Evolutionary analysis shows that the deepwater rice–specific haplotype was derived from standing variation in wild rice and selected for deepwater rice cultivation in Bangladesh.

中文翻译：

---

乙烯-赤霉素信号是水稻适应周期性洪水的基础

水稻如何抵御洪水 深水水稻品种在被洪水淹没时长得更高，这是由植物激素赤霉素和乙烯驱动的生长反应。这使叶子保持在水面之上。黑羽等人。鉴定了这种表型背后的基因，这些基因编码赤霉素生物合成途径的一个组成部分及其调节乙烯反应转录因子。这种遗传中继驱动植物茎节间的生长以响应洪水。现代栽培深水水稻已被驯化以适应孟加拉国的季风季节，它是从更广泛的地理区域野生稻品种中发现的遗传变异中出现的。科学，这个问题 p。181 赤霉素生物合成的乙烯诱导激活有助于水稻在水淹地块中长时间浸没。大多数植物在被洪水淹没时表现不佳。某些被称为深水水稻的水稻品种通过激活茎的节间生长以保持在水面之上，从而在周期性洪水和随之而来的缺氧中幸存下来。在这里，我们确定了赤霉素生物合成基因 SD1 (SEMIDWARF1)，其功能丧失等位基因引发了水稻绿色革命，负责淹没诱导的节间伸长。当淹没时，携带深水水稻特异性 SD1 单倍型的植物会放大信号中继，其中 SD1 基因被乙烯响应转录因子 OsEIL1a 转录激活。SD1 蛋白指导赤霉素的合成增加，主要是 GA4，从而促进节间伸长。