Transcriptome analysis of leafy near‐isogenic lines provides molecular insights into floral transition in maize (Zea mays)

Abstract

AbstractLeafy (Lfy1) is a typical late‐flowering mutant with locus being fine‐mapped, but its underlying molecular mechanism is unknown. In this study, two near‐isogenic lines, with and without the Lfy1 locus, were developed for phenotypic and transcriptional analysis of Lfy1‐mediated floral transition. Phenotypic observation showed that wild‐type (WT) plants transited into the tassel primordium at the V6 (6 expanded leaves) stage, whereas the Lfy1 mutant maintained the vegetative stage up to the V9 stage. Transcriptome analysis of shoot tips of both lines revealed more differentially expressed genes (DEGs) at the V5 (394) than the V3 stage (227). Functional enrichment analysis showed that circadian clock pathway genes exhibited lower expression levels in the Lfy1 mutant than in the WT at the V5 stage. A few integrator genes that functioned as downstream regulators of circadian clock genes also showed a lower transcript abundance in mutant lines, suggesting that the Lfy1‐mediated late‐flowering phenotype was partially caused by inefficient expression of circadian clock pathway genes. These results provide molecular clues for the late‐flowering phenotype of the Lfy1 mutant.