Department of Agronomy, Iowa State University, Ames, Iowa 50011.
Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, Iowa 50011.
Plant Physiol. 2020 Dec;184(4):1927-1940. doi: 10.1104/pp.20.00632. Epub 2020 Oct 22.
A "smart canopy" ideotype has been proposed with leaves being upright at the top and more horizontal toward the bottom of the plant to maximize light interception and conversion efficiencies, and thus increasing yield. The genetic control of leaf angle has, to date, been studied on one or two leaves, or data have been merged from multiple leaves to generate average values. This approach has limited our understanding of the diversity of leaf angles across layers and their genetic control. Genome-wide association studies and quantitative trait loci mapping studies in sorghum () were performed using layer-specific angle data collected manually and via high-throughput phenotyping strategies. The observed distribution of angles in indoor and field settings is opposite to the ideotype. Several genomic regions were associated with leaf angle within layers or across the canopy. The expression of the brassinosteroid-related transcription factor / and the auxin-transporter were found to be highly correlated with the distribution of angles at different layers. The application of a brassinosteroid biosynthesis inhibitor could not revert the undesirable overall angle distribution. These discoveries demonstrate that the exploitation of layer-specific quantitative trait loci/genes will be instrumental to reversing the natural angle distribution in sorghum according to the "smart canopy" ideotype.
已经提出了一种“智能冠层”理想型，其叶片在植株顶部保持直立，而在植株下部更加水平，以最大限度地提高光捕获和转化效率，从而提高产量。迄今为止，对叶片角度的遗传控制已经在一片或两片叶片上进行了研究，或者从多片叶片中合并数据以生成平均值。这种方法限制了我们对不同层次叶片角度多样性及其遗传控制的理解。使用手动和高通量表型策略收集的分层角度数据，对高粱进行了全基因组关联研究和数量性状位点作图研究。在室内和田间环境中观察到的角度分布与理想型相反。几个基因组区域与叶片内部或冠层内的叶片角度相关。发现油菜素内酯相关转录因子 / 和生长素转运蛋白 的表达与不同层之间角度的分布高度相关。应用油菜素内酯生物合成抑制剂不能使不理想的整体角度分布恢复正常。这些发现表明，根据“智能冠层”理想型，利用分层的数量性状基因座/基因将有助于改变高粱的自然角度分布。
