Comparative Analysis, Characterization and Evolutionary Study of Dirigent Gene Family in Cucurbitaceae and Expression of Novel Dirigent Peptide against Powdery Mildew Stress

Abstract

Dirigent (DIR) proteins are induced under various stress conditions and involved in sterio- and regio-selective coupling of monolignol. A striking lack of information about dirigent genes in cucurbitaceae plants underscores the importance of functional characterization. In this study, 112 DIR genes were identified in six species, and 61 genes from major cultivated species were analyzed. DIRs were analyzed using various bioinformatics tools and complemented by expression profiling. Phylogenetic analysis segregated the putative DIRs into six distinctively known subgroups. Chromosomal mapping revealed uneven distribution of genes, whereas synteny analysis exhibited that duplication events occurred during gene evolution. Gene structure analysis suggested the gain of introns during gene diversification. Gene ontology (GO) enrichment analysis indicates the participation of proteins in lignification and pathogen resistance activities. We also determined their organ-specific expression levels in three species revealing preferential expression in root and leaves. Furthermore, the number of CmDIR (CmDIR1, 6, 7 and 12) and ClDIR (ClDIR2, 5, 8, 9 and 17) genes exhibited higher expression in resistant cultivars after powdery mildew (PM) inoculation. In summary, based on the expression and in-silico analysis, we propose a role of DIRs in disease resistance mechanisms.

Comparative transcriptome profiling reveals the role of phytohormones and phenylpropanoid pathway in early-stage resistance against powdery mildew in watermelon (Citrullus lanatus L.)

“…Conversely, the concentration of conidial cells was unaffected in resistant plants, and slight spores were measured after nine days post-inoculation in resistance lines. The results were in line with the previous reports of the high resistance and susceptible nature of watermelon lines used in the current study ( Yadav et al., 2021b ).…”

“…A watermelon PM inoculation experiment was carried out using PM fungus P. xanthii race ‘2F’ routinely maintained on the sensitive watermelon lines under greenhouse conditions at the cucurbit germplasm innovation and genetic improvement center, Northwest A & F University, Yangling, Shaanxi, China ( Yadav et al., 2021b ). As per previous reports, melon differential lines were used for PM race confirmation.…”

“…As per previous reports, melon differential lines were used for PM race confirmation. The conidial suspension (10 5 spores/mL in 0.02% Tween 20) was prepared by young spores collected from infected leaves ( Mandal et al., 2018 ; Mandal et al., 2020 ; Gao et al., 2021 ; Yadav et al., 2021b ). Artificial inoculation was done by evenly spraying conidial suspension on the leaf surface of three-to-four leaf stage healthy seedlings.…”

Systematic Genome-Wide Study and Expression Analysis of SWEET Gene Family: Sugar Transporter Family Contributes to Biotic and Abiotic Stimuli in Watermelon

“…Actin gene was selected as an internal control to normalize transcriptional levels. Genes and internal controls were amplified in triplicate, and relative gene expression levels were calculated using the 2 −∆∆ CT method [63]. The expression level of all identified ClaSWEET genes was log2 transformed and normalized to obtain a heatmap.…”

A Novel QTL for Resistance to Phytophthora Crown Rot in Squash

“…On the other hand, Methyl esterase-11 and L-aspartate oxidase genes inhibit the development of fungal diseases by enhancing pectin esterification and through NAD + regulation, respectively [53,54]. SNP C009351 lies within a dirigent protein gene Cp4.1LG13g09560 which confers resistance to powdery mildew in Cucurbitaceae family [55]. SNP marker C010730 was located within Cp4.1LG13g07250, a gene encoding a Eukaryotic translation initiation factor 3 subunit F involved in resistance against papaya ringspot virus in papaya [56].…”