Genome-wide identification, characterization and expression analysis of the ABA receptor PYL gene family in response to ABA, photoperiod, and chilling in vegetative buds of Liriodendron chinense

Abstract

Abscisic acid (ABA) is a signaling phytohormone in plants to improve stress adaption under harsh environments. ABA is sensed by the pyrabactin resistance1/PYR1-like/regulatory components of the ABA receptor (PYR1/PYL/RCAR) (named PYLs) and is the core regulator of ABA stress signaling. ABA receptor PYL gene family have been well studied in rubber tree, apple, Theobroma cacao, Ricinus communis, and Vitis vinifera. We first revealed the genome-wide comprehensive analysis to classify the PYL genes in the L. chinense. This study highlighted the seven LchiPYL genes in the L. chinense genome. The detailed investigations about gene structure variations, chromosomal distributions, phylogenetic tree, 3D structure, motif analysis, cis-regulatory elements, subcellular location, and expression profiles in buds and stress responses were carried out in this article. Phylogenetic tree analysis exploited that the seven LchiPYL genes were divided into four groups (Group I–IV) from L. chinense, and three were highly linked with other species. By analyzing the cis-elements in the promoters, we identified five hormones-, six stress-, three growth and biological process, and two metabolic-related responsive elements. The expression analysis showed that all seven genes were up-and down-regulated against response to ABA, photoperiod, chilling, and chilling + photoperiod treatments. Our findings opened up new future research directions and provided insight into the PYL family genes in Liriodendron chinense.