PT  - JOURNAL ARTICLE
AU  - Lin, Xuelei
AU  - Xu, Yongxin
AU  - Wang, Dongzhi
AU  - Yang, Yiman
AU  - Zhang, Xiaoyu
AU  - Bie, Xiaomin
AU  - Wang, Hongzhe
AU  - Jiang, Jiafu
AU  - Ding, Yiliang
AU  - Lu, Fei
AU  - Zhang, Xueyong
AU  - Zhang, Xiansheng
AU  - Fu, Xiangdong
AU  - Xiao, Jun
TI  - Systematic mining and genetic characterization of regulatory factors for wheat spike development
AID  - 10.1101/2022.11.11.516122
DP  - 2022 Jan 01
TA  - bioRxiv
PG  - 2022.11.11.516122
4099  - http://biorxiv.org/content/early/2022/11/11/2022.11.11.516122.short
4100  - http://biorxiv.org/content/early/2022/11/11/2022.11.11.516122.full
AB  - Spike architecture largely affects grain number embraced, which is a key factor influencing wheat grain yield. Here, we systematically explore the genetic regulation network governing wheat spike development by integration of multi-omic data with population genetics. Transcriptome and epigenome profile of shoot apex at eight developmental stages were generated. Gain-of-chromatin accessibility and changes of H3K27me3 coordinately associate with the progressive transcriptome alteration for flowering. A core transcriptional regulation network (TRN) that likely drives various meristematic cell identities transition to form spike was constructed. Integration of the TRN and genome-wide association analysis (GWAS), 260 transcription factors (TFs) were identified, including 52 characterized factors in crops, but mostly unstudied. Multi-layer regulatory module among TaSPL6, TaMADS34 and TaMADS14 suggested by TRN was further validated experimentally. About 85 novel TFs contain high impact mutant lines in KN9204 TILLING library. Of them, 44 TFs with homozygous mutation, including NAC, bHLH, MYB, and WRKY, show altered spike architecture. In particular, TaMYB4-A positively regulates fertile spikelet number likely via regulating hormones homeostasis or signaling, while acting downstream of- and repressed by WFZP. The elite allele of TaMYB4-A, with higher expression and more fertile spikelet, was selected during breeding process in China. Collectively, we present invaluable resource of high-confidence regulators and novel strategy for understanding the genetic regulation of wheat spike development systematically.Competing Interest StatementThe authors have declared no competing interest.