School of Life Sciences and Engineering, Southwest University of Science and Technology, Mianyang 629000, Sichuan, China
Xiujunan Yang
School of Agriculture, Food and Wine, Waite Research Institute, The University of Adelaide, Adelaide 5005, SA, Australia
Yueya Zhang
School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
Chaoqun Shen
School of Agriculture, Food and Wine, Waite Research Institute, The University of Adelaide, Adelaide 5005, SA, Australia; School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
Jin Shi
School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
Chongjing Xia
School of Life Sciences and Engineering, Southwest University of Science and Technology, Mianyang 629000, Sichuan, China
Taohong Fang
School of Life Sciences and Engineering, Southwest University of Science and Technology, Mianyang 629000, Sichuan, China
Qiang Tu
School of Life Sciences and Engineering, Southwest University of Science and Technology, Mianyang 629000, Sichuan, China
Ling Li
School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
Xinli Zhou
School of Life Sciences and Engineering, Southwest University of Science and Technology, Mianyang 629000, Sichuan, China
Dabing Zhang
School of Agriculture, Food and Wine, Waite Research Institute, The University of Adelaide, Adelaide 5005, SA, Australia; School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
Gang Li
School of Agriculture, Food and Wine, Waite Research Institute, The University of Adelaide, Adelaide 5005, SA, Australia; Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, Jiangsu, China; Corresponding author.
In flowering plants, the inflorescence meristem (IM) provides founder cells to form successive floral meristems, which are precursors of fruits and seeds. The activity and developmental progression of IM are thus critical for yield production in seed crops. In some cereals, such as rice (Oryza sativa) and maize (Zea mays), the size of undifferentiated IM, which is located at the inflorescence apex, is positively associated with yield traits such as spikelet number. However, the relationship between IM size and yield-related spike traits remains unknown in the Triticeae tribe. Here we report that IM size has a negative correlation with yield traits in barley (Hordeum vulgare). Three FASCIATED EAR (FEA) orthologs, HvFEA2, HvFEA3, and HvFEA4, regulate IM size and spike morphogenesis and ultimately affect yield traits. Three HvFEAs genes are highly expressed in developing spikes, and all three loss-of-function mutants exhibit enlarged IM size, shortened spikes, and reduced spikelet number, which may lead to reduced grain yield. Natural variations identified in HvFEAs indicate selection events during barley domestication. We further reveal that HvFEA4, as a transcription factor, potentially targets multiple pathways during reproductive development, including transcriptional control, phytohormone signaling, and redox status. The roles of barley FEA genes in limiting IM size and promoting spikelet formation suggest the potential of increasing yield by manipulating IM activity.
