Comparative genomic analysis of MYB transcription factors for cuticular wax biosynthesis and drought stress tolerance in Helianthus annuus L.

Abstract

Sunflower is an important oil-seed crop in Pakistan, it is mainly cultivated in the spring season. It is severely affected by drought stress resulting in lower yield. Cuticular wax acts as the first defense line to protect plants from drought stress condition. It seals the aerial parts of plants and reduce the water loss from leaf surfaces. Various myeloblastosis (MYB) transcription factors (TFs) are involved in biosynthesis of epicuticular waxes under drought-stress. However, less information is available for MYB, TFs in drought stress and wax biosynthesis in sunflower. We used different computational tools to compare the Arabidopsis MYB, TFs involved in cuticular wax biosynthesis and drought stress tolerance with sunflower genome. We identified three putative MYB genes ( MYB16, MYB94 and MYB96 ) in sunflower along with their seven homologs in Arabidopsis . Phylogenetic association of MYB TFs in Arabidopsis and sunflower indicated strong conservation of TFs in plant species. From gene structure analysis, it was observed that intron and exon organization was family-specific. MYB TFs were unevenly distributed on sunflower chromosomes. Evolutionary analysis indicated the segmental duplication of the MYB gene family in sunflower. Quantitative Real-Time PCR revealed the up-regulation of three MYB genes under drought stress. The gene expression of MYB16 , MYB94 and MYB96 were found many folds higher in experimental plants than control. The present study provided the first insight into MYB TFs family's characterization in sunflower under drought stress conditions and wax biosynthesis TFs.

Co-expression of stress-responsive regulatory genes, MuNAC4, MuWRKY3 and MuMYB96 associated with resistant-traits improves drought adaptation in transgenic groundnut (Arachis hypogaea l.) plants

“…MuMYB96 transcript levels were significantly increased in multigene transgenic plants and also resulted in the overexpression of its downstream target genes KCS6 and KCR1, supporting their role increased cuticular wax accumulation. Earlier drought induced expression of MYB96 and its downstream genes KCS6 and KCR1 were reported in response to drought stress (Lee et al, 2016;Zhang et al, 2019;Lewandowska et al, 2020;Ahmad et al, 2021;Huang et al, 2022) (Figure 8).…”

Comparative transcriptome and coexpression network analysis reveals key pathways and hub candidate genes associated with sunflower (Helianthus annuus L.) drought tolerance

“…One study revealed that most AP2/ERF transcription factors exhibit root-specific expression [ 112 ], which is similar to the results of our study, in which we detected a greater number of ERF transcription factors in roots than in leaves. Some recent studies have shown that some MYB genes in sunflowers are highly expressed under drought stress [ 113 ]. According to our results, MYB genes were more downregulated in the leaves than in the roots.…”

Genome-Wide Identification of Cotton (Gossypium spp.) Glycerol-3-Phosphate Dehydrogenase (GPDH) Family Members and the Role of GhGPDH5 in Response to Drought Stress

“…Transcription factors (TFs) are pivotal modulators of crop improvement, and facilitate the activation of regulatory mechanisms in plants [ 22 , 34 ]. The promoter region of cotton GPDH genes, contains numerous transcription factor binding sites, including multiple MYB-associated transcription factor recognition sites, and MYB has been shown to be associated with the abiotic stress response in plants in several studies [ 35 , 36 , 37 , 38 ]. Likewise, the hormone constitutes one of the important factors in affecting cotton growth and development, and abundant stress-related hormone response cis-elements further illustrate the potential of GPDH in coping with abiotic stresses.…”