Comprehensive Analysis of TaNCED Gene Family in Wheat Vernalization Process.

Abstract

9-cis-epoxycarotenoid dioxygenases (NCEDs), serving as the rate-limiting enzymes in abscisic acid (ABA) biosynthesis, play a pivotal role in regulating plant growth and development, as well as responses to abiotic stresses. Despite their agronomic importance, the molecular dialog between ABA signaling and vernalization, a cold-induced switch from vegetative to reproductive growth in wheat, remains poorly characterized, particularly regarding the TaNCED gene family members. Here, we systematically identified 13 TaNCED members in hexaploid wheat, followed by multi-omics characterization encompassing physicochemical properties, exon-intron architectures, conserved catalytic domains, protein motifs, and cis-acting elements. By analyzing transcriptome data from vernalization treatments, we profiled the expression patterns of TaNCED genes during vernalization. Notably, TaNCED5-6A, TaNCED5-6B, and TaNCED5-6D exhibited significant upregulation in vernalized leaves and tiller buds, while maintaining basal expression in the shoot apical meristem, the site of floral induction. This tissue-specific expression pattern implicates their specialized role in mediating vernalization responses via ABA biosynthesis. Collectively, our findings provide novel insights into the regulatory mechanisms of ABA-mediated vernalization in wheat and offer valuable targets for vernalization efficiency in cereal breeding programs.