Genome-wide investigation of Hydroxycinnamoyl CoA: Shikimate Hydroxycinnamoyl Transferase (HCT) gene family in Carthamus tinctorius L.

Abstract

Hydroxycinnamoyl-CoA: shikimate hydroxycinnamoyl transferase (HCT) is mainly associated with monolignol biosynthesis, a central precursor to producing guaiacyl and syringyl lignins in plants. However, the explicit regulatory mechanism of HCT-mediated monolignol biosynthesis in plants still remained unclear. Here, the genome-wide analysis of the HCT gene family in Carthamus tinctorius as a target for understanding growth, development, and stress-responsive mechanisms was investigated. A total of 82 CtHCT genes were identified and characterized. Most of the CtHCTs proteins demonstrated the presence of two common conserved domains, including HXXXD and DFGWG. In addition, the conserved structure of protein motifs, PPI network, cis-regulatory units, and gene structure analysis demonstrated several genetic determinants reflecting the wide range of functional diversity of CtHCT-encoding genes. The observed expression analysis of CtHCT genes in different flowering stages under normal conditions partially highlighted their putative roles in plant growth and development pathways. Moreover, CtHCT genes appeared to be associated with abiotic stress responses as validated by the expression profiling in various flowering phases under light irradiation and MeJA treatment. Altogether, these findings provide new insights into identifying crucial molecular targets associated with plant growth and development and present practical information for understanding abiotic stress-responsive mechanisms in plants.

Keywords

• abiotic stress
• Carthamus tinctorius
• expression diversity
• HCT gene family
• monolignol biosynthesis