Revealing the role of SEPALLATA-like genes in determining cereal inflorescence architecture using genome editing approach

Li G1, Kuijer H1, Wu D2, Zhu W2, Liang W2, Burton R1, Dreni L2 and Zhang D1

  1. School of Agriculture, Food and Wine, University of Adelaide.
  2. School of Life Sciences and Biotechnology, Shanghai Jiao Tong University.

Over 50% of the global populations calories are obtained from cereal grains produced from spikelets on a flowering structure called an inflorescence. Improvements in crop yield could be made by increasing spikelet number. To achieve this goal, we need to gain a deeper understanding of the mechanisms underpinning inflorescence architecture. The shape of an inflorescence varies between cereals, ranging from highly branched in rice (Oryza sativa) termed a panicle, to a much more compact spike in barley (Hordeum vulgare) and wheat (Triticum spp.). One SEPALLATA (SEP) MADS domain transcription factor gene OsMADS34 has recently been identified that control inflorescence architecture and seed number in rice. To further understand the role of SEP genes, i.e. OsMADS1, OsMADS5 and OsMADS34 in the LOFSEP clade from rice and their counterparts in barley in regulating the inflorescence development, we are using gene-editing approaches in creating single mutants and high-order mutants of these genes in rice and barley respectively. Our preliminary data revealed that rice LOFSEPs play collaborative role in determining rice panicle branching, while barley homologs of rice OsMADS1, OsMADS5 and OsMADS34 showed conserved and divergent function in specifying barley inflorescence development.