Frontiers Science Center for Molecular Design Breeding (MOE), Department of Plant Genetics and Breeding, China Agricultural University, Beijing, 100193, China.
Plant J. 2024 Oct;120(2):429-444. doi: 10.1111/tpj.16948. Epub 2024 Jul 25.
The tiller angle is an important agronomic trait that determines plant architecture and grain yield in rice (Oryza sativa L.). However, the molecular regulation mechanism of the rice tiller angle remains unclear. Here, we identified a rice tiller angle gene, LARGE TILLER ANGLE 1 (LATA1), using the MutMap approach. LATA1 encodes a C3H2C3-type RING zinc finger E3 ligase and the conserved region of the RING zinc finger is essential for its E3 activity. LATA1 was highly expressed in the root and tiller base and LATA1-GFP fusion protein was specifically localized to the nucleus. The mutation of LATA1 significantly reduced indole-3-acetic acid content and attenuated lateral auxin transport, thereby resulting in defective shoot gravitropism and spreading plant architecture in rice. Further investigations found that LATA1 may indirectly affect gravity perception by modulating the sedimentation rate of gravity-sensing amyloplasts upon gravistimulation. Our findings provide new insights into the molecular mechanism underlying the rice tiller angle and new genetic resource for the improvement of plant architecture in rice.
分蘖角度是决定水稻（Oryza sativa L.）株型和产量的一个重要农艺性状。然而，水稻分蘖角度的分子调控机制尚不清楚。本研究利用 MutMap 方法鉴定了一个水稻分蘖角度基因 LARGE TILLER ANGLE 1（LATA1）。LATA1 编码一个 C3H2C3 型 RING 锌指 E3 连接酶，其 RING 锌指的保守区域对于其 E3 活性是必需的。LATA1 在根和分蘖基部高表达，LATA1-GFP 融合蛋白特异性定位于细胞核。LATA1 的突变显著降低了吲哚-3-乙酸的含量，并减弱了侧生生长素的运输，从而导致水稻的 shoot 向地性缺陷和展开的株型。进一步的研究发现，LATA1 可能通过调节重力刺激下重力感受淀粉体的沉降速率，间接影响重力感知。本研究结果为水稻分蘖角度的分子机制提供了新的见解，并为水稻株型改良提供了新的遗传资源。
