An orchestrated ethylene–gibberellin signaling cascade contributes to mesocotyl elongation and emergence of rice direct seeding

• DOI: 10.1111/jipb.13671
• Publication Date: 2024-05-16T04:33:56Z
• Authors: Yusong Lyu; Xinli Dong; Shipeng Niu; Ruijie Cao; Gaoneng Shao; Zhonghua Sheng; Guiai Jiao; Lihong Xie; Shikai Hu; Shaoqing Tang; Xiangjin Wei; Peisong Hu
• Keywords: Elongation

ABSTRACT A mechanized direct seeding of rice with less labor and water usage, has been widely adopted. However, this approach requires varieties that exhibit uniform seedling emergence. Mesocotyl elongation (ME) offers the main drive fast emergence seedlings from soils; nevertheless, its genetic basis remains unknown. Here, we identify a major quantitative trait locus Elongation1 ( qME1 ), an allele Green Revolution gene Semi‐Dwarf1 SD1 encoding GA20‐oxidase for gibberellin (GA) biosynthesis . ME1 expression is strongly induced by soil depth ethylene. When grains are direct‐seeded in soils, ethylene core signaling factor OsEIL1 directly promotes transcription, accelerating bioactive GA biosynthesis. The GAs further degrade DELLA protein SLENDER RICE 1 (SLR1), alleviating inhibition PHYTOCHROME‐INTERACTING FACTOR‐LIKE13 (OsPIL13) to activate downstream expansion OsEXPA4 ultimately promote ME ancient traits long mesocotyl strong ability wild landrace were gradually lost company dwarf breeding process, elite ‐R (D349H) found some modern Geng (long lengths) northern China, which can be used varieties. Furthermore, ectopic high driven mesocotyl‐specific promoters resulted plants could without obvious plant architecture or yield penalties. Collectively, reveal molecular mechanism ME, provide useful information new suitable direct‐seeding practice.