State Key Laboratory for Agrobiotechnology and Key Laboratory of Crop Heterosis and Utilization (MOE) and Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China.
New Phytol. 2021 Jul;231(2):814-833. doi: 10.1111/nph.17388. Epub 2021 May 8.
Grain yield in bread wheat (Triticum aestivum L.) is largely determined by inflorescence architecture. Zang734 is an endemic Tibetan wheat variety that exhibits a rare triple spikelet (TRS) phenotype with significantly increased spikelet/floret number per spike. However, the molecular basis underlying this specific spike morphology is completely unknown. Through map-based cloning, the causal genes for TRS trait in Zang734 were isolated. Furthermore, using CRISPR/Cas9-based gene mutation, transcriptome sequencing and protein-protein interaction, the downstream signalling networks related to spikelet formation and awn elongation were defined. Results showed that the null mutation in WFZP-A together with deletion of WFZP-D led to the TRS trait in Zang734. More interestingly, WFZP plays a dual role in simultaneously repressing spikelet formation gene TaBA1 and activating awn development genes, basically through the recruitments of chromatin remodelling elements and the Mediator complex. Our findings provide insights into the molecular bases by which WFZP suppresses spikelet formation but promotes awn elongation and, more importantly, define WFZP-D as a favourable gene for high-yield crop breeding.
小麦的籽粒产量在很大程度上取决于花序结构。藏 734 是一种特有的西藏小麦品种，表现出罕见的三小穗（TRS）表型，小穗/小花数显著增加。然而，这种特定穗型的分子基础尚完全未知。通过图位克隆，分离了藏 734 中 TRS 性状的候选基因。此外，通过 CRISPR/Cas9 基因突变、转录组测序和蛋白质-蛋白质相互作用，定义了与小穗形成和芒伸长相关的下游信号网络。结果表明，WFZP-A 的无效突变以及 WFZP-D 的缺失导致了藏 734 的 TRS 表型。更有趣的是，WFZP 同时通过募集染色质重塑元件和中介体复合物，负调控小穗形成基因 TaBA1 并激活芒发育基因，从而发挥双重作用。我们的研究结果为 WFZP 抑制小穗形成但促进芒伸长的分子基础提供了新的认识，更重要的是，将 WFZP-D 定义为高产作物育种的有利基因。
