Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
National Key Facility of Crop Gene Resources and Genetic Improvement, Beijing 100081, China.
Plant Cell. 2024 May 29;36(6):2393-2409. doi: 10.1093/plcell/koae083.
Optimizing the root architecture of crops is an effective strategy for improving crop yields. Soil compaction is a serious global problem that limits crop productivity by restricting root growth, but the underlying molecular mechanisms are largely unclear. Here, we show that ethylene stimulates rice (Oryza sativa) crown root development in response to soil compaction. First, we demonstrate that compacted soil promotes ethylene production and the accumulation of ETHYLENE INSENSITIVE 3-LIKE 1 (OsEIL1) in rice roots, stimulating crown root primordia initiation and development, thereby increasing crown root number in lower stem nodes. Through transcriptome profiling and molecular analyses, we reveal that OsEIL1 directly activates the expression of WUSCHEL-RELATED HOMEOBOX 11 (OsWOX11), an activator of crown root emergence and growth, and that OsWOX11 mutations delay crown root development, thus impairing the plant's response to ethylene and soil compaction. Genetic analysis demonstrates that OsWOX11 functions downstream of OsEIL1. In summary, our results demonstrate that the OsEIL1-OsWOX11 module regulates ethylene action during crown root development in response to soil compaction, providing a strategy for the genetic modification of crop root architecture and grain agronomic traits.
优化作物根系结构是提高作物产量的有效策略。土壤板结是一个全球性的严重问题，它通过限制根系生长来限制作物生产力，但其中的潜在分子机制在很大程度上还不清楚。在这里，我们表明乙烯会刺激水稻（Oryza sativa）冠根的发育，以应对土壤板结。首先，我们证明紧实的土壤会促进乙烯的产生和 ETHYLENE INSENSITIVE 3-LIKE 1（OsEIL1）在水稻根系中的积累，刺激冠根原基的起始和发育，从而增加下部茎节点的冠根数量。通过转录组分析和分子分析，我们揭示了 OsEIL1 直接激活 WUSCHEL-RELATED HOMEOBOX 11（OsWOX11）的表达，OsWOX11 是冠根出现和生长的激活因子，而 OsWOX11 的突变会延迟冠根的发育，从而损害植物对乙烯和土壤板结的反应。遗传分析表明，OsWOX11 是 OsEIL1 的下游作用因子。总之，我们的研究结果表明，OsEIL1-OsWOX11 模块在响应土壤板结的冠根发育过程中调节乙烯的作用，为作物根系结构和谷物农艺性状的遗传改良提供了策略。
