中国农业大学Feng Tian和Jigang Li共同合作，近期取得重要工作进展。他们研究提出，玉米智能冠层结构在高密度下可提高产量。相关研究成果2024年6月12日在线发表于《自然》杂志上。

据介绍，增加种植密度是提高玉米产量的关键策略。密集种植的理想模式需要一个“智能冠层”，不同冠层的叶角经过不同的优化，以最大限度地提高截光和光合作用等功能。

研究人员鉴定了智能冠层1（lac1）的叶角结构，它是一种天然突变体，具有直立的上部叶片、较少直立的中部叶片和相对平坦的下部叶片。在密植条件下，lac1提高了光合能力，减弱了避荫反应。lac1编码一种主要调节上叶角的油菜素甾体C-22羟化酶。光敏色素A光感受器在阴凉处积累，并与转录因子RAVL1相互作用，通过26S蛋白酶体促进其降解，从而减弱RAVL1对lac1的激活并降低油菜素甾体水平。这最终会降低密集田地的上部叶角。大规模田间试验表明，lac1能在高密度条件下提高玉米产量。为了快速将lac1引入育种种质，研究人员转化了单倍体诱导物，并从20个不同的自交系中恢复了纯合的lac1编辑。测试的双单倍体一致获得了智能的类似冠层的植物结构。

总之，这一研究为开发高密度耐受品种提供了一个重要的目标和加速策略，其中lac1可作为玉米智能冠层进一步工程化的遗传基础。

附：英文原文

Title: Maize smart-canopy architecture enhances yield at high densities

Author: Tian, Jinge, Wang, Chenglong, Chen, Fengyi, Qin, Wenchao, Yang, Hong, Zhao, Sihang, Xia, Jinliang, Du, Xian, Zhu, Yifan, Wu, Lishuan, Cao, Yan, Li, Hong, Zhuang, Junhong, Chen, Shaojiang, Zhang, Huayuan, Chen, Qiuyue, Zhang, Mingcai, Deng, Xing Wang, Deng, Dezhi, Li, Jigang, Tian, Feng

Issue&Volume: 2024-06-12

Abstract: Increasing planting density is a key strategy to enhance maize yields1-3. An ideotype for dense planting requires a ‘smart canopy’ with leaf angles at different canopy layers differentially optimized to maximize light interception and photosynthesis4-6, amongst other features. Here, we identified leaf angle architecture of smart canopy 1 (lac1), a natural mutant possessing upright upper leaves, less erect middle leaves and relatively flat lower leaves. lac1 has improved photosynthetic capacity and weakened shade-avoidance responses under dense planting. lac1 encodes a brassinosteroid C-22 hydroxylase that predominantly regulates upper leaf angle. Phytochrome A photoreceptors accumulate in shade and interact with the transcription factor RAVL1 to promote its degradation via the 26S proteasome, thereby attenuating RAVL1 activation of lac1 and reducing brassinosteroid levels. This ultimately decreases upper leaf angle in dense fields. Large-scale field trials demonstrate lac1 boosts maize yields under high densities. To quickly introduce lac1 into breeding germplasm, we transformed a haploid inducer and recovered homozygous lac1 edits from 20 diverse inbred lines. The tested doubled haploids uniformly acquired smart-canopy-like plant architecture. We provide an important target and an accelerated strategy for developing high-density-tolerant cultivars, with lac1 serving as a genetic chassis for further engineering of a smart canopy in maize.

DOI: 10.1038/s41586-024-07669-6

Source: https://www.nature.com/articles/s41586-024-07669-6