Loose Panicle1 encoding a novel WRKY transcription factor, regulates panicle development, stem elongation, and seed size in foxtail millet [Setaria italica (L.) P. Beauv.]

• DOI: 10.1371/journal.pone.0178730
• Publication Date: 2017-06-01T13:53:27Z
• Authors: Jishan Xiang; Sha Tang; Hui Zhi; Guanqing Jia; Huajun Wang; Xianmin Diao
• Keywords: WRKY protein domain; Setaria; Panicle; Foxtail

Panicle development is an important agronomic trait that aids in determining crop productivity. Foxtail millet and its wild ancestor green foxtail have recently been used as model systems to dissect gene functions. Here, we characterized a recessive mutant of millet, loose-panicle 1 (lp1), which showed pleiotropic phenotypes, such lax primary branching pattern, aberrant branch morphology, semi-dwarfism, enlarged seed size. The loose panicle phenotype was attributed increased lengths decreased numbers. Map-based cloning, combined with high-throughput sequencing, revealed LP1, encodes novel WRKY transcription factor, responsible for the phenotype. A phylogenetic analysis LP1 belongs Group I subfamily, possesses two domains (WRKY II). single G-to-A transition fifth intron resulted three disorganized splicing events plants. For each these splice variants, normal C2H2 motif II domain completely disrupted, resulting loss-of-function mutation. mRNA expressed all tissues examined, higher expression levels observed inflorescences, roots, seeds at grain-filling stage. subcellular localization predominantly accumulated nucleus, confirmed role transcriptional regulator. This study provides insights into roles proteins regulating reproductive organ plants may help develop molecular markers associated yields.