Genome-Wide Identification and Characterization of GhCOMT Gene Family during Fiber Development and Verticillium Wilt Resistance in Cotton

Abstract

Caffeic acid O-methyltransferases (COMTs) play an essential role in lignin synthesis procession, especially in the plant’s phenylalanine metabolic pathway. The content of COMT genes in cotton and the relationship between their expression patterns have not been studied clearly in cotton. In this study, we have identified 190 COMT genes in cotton, which were classified into three groups (I, II and III), and mapped on the cotton chromosomes. In addition, we found that 135 of the 190 COMT genes result from dispersed duplication (DSD) and whole-genome duplication (WGD), indicating that DSD and WGD were the main forces driving COMT gene expansion. The Ka/Ks analysis showed that GhCOMT43 and GhCOMT41 evolved from GaCOMT27 and GrCOMT14 through positive selection. The results of qRT-PCR showed that GhCOMT13, GhCOMT28, GhCOMT39 and GhCOMT55 were related to lignin content during the cotton fiber development. GhCOMT28, GhCOMT39, GhCOMT55, GhCOMT56 and GhCOMT57 responded to Verticillium Wilt (VW) and maybe related to VW resistance through lignin synthesis. Conclusively, this study found that GhCOMTs were highly expressed in the secondary wall thickening stage and VW. These results provide a clue for studying the functions of GhCOMTs in the development of cotton fiber and VW resistance and could lay a foundation for breeding cotton cultivates with higher quantity and high resistance to VW.

RNA-Seq and Iso-Seq Reveal the Important Role of COMT and CCoAOMT Genes in Accumulation of Scopoletin in Noni (Morinda citrifolia)

“…The preferred substrates of COMT are caffeoyl aldehyde and 5-hydroxyconiferaldehyde [ 25 , 46 ]. According to the annotation of metabolic pathways in transcriptome sequencing, it is known that in the accumulation of scopoletin in noni, the transformation from caffeic acid to ferulic acid was realized.…”

MYB24, MYB144, and MYB168 positively regulate suberin biosynthesis at potato tuber wounds during healing

“…St4CL contains a highly conserved SGTT-PKGV (Ser Gly Thr Thr-Pro Lys Gly Val) amino acids in AMP-binding domain (Figure S3a) (Mo et al, 2022) and is clustered with Nt4CL1, which has been proved to regulate the biosynthesis of phenolic compounds in Nicotiana tabacum (Figure S3b) (Zhao et al, 2016). Similarly，StOMT contains a conserved domain (SAM binding site, Figure S4a) (Wu et al, 2021) and is clustered with AtOMT7, which has been proved to take part in the biosynthesis of lignin in Arabidopsis (Figure S4b) (Raes et al, 2003).RT-qPCR results showed that wounding significantly upregulated the expression of StPAL, StOMT, and St4CL, which were 182-, 41-, and 142-fold higher at 1 day than that at 0 day, respectively (Figure 3b-d). After wounding, the expression of these three genes remained at high levels, and the expression levels at the early stage (1 day) were slightly higher than those at the late stage (7 days).…”