Identification of MYB gene family and functional analysis of GhMYB4 in cotton (Gossypium spp.)

Authors: DAI, YUANLI - Zhengzhou University; LIU, SHANG - Chinese Academy Of Agricultural Sciences; ZUO, DONGYUN - Chinese Academy Of Agricultural Sciences; WANG, QIAOLIAN - Chinese Academy Of Agricultural Sciences; LU, LIMIN - Chinese Academy Of Agricultural Sciences; ZHANG, YOUPING - Chinese Academy Of Agricultural Sciences; CHENG, HAILIANG - Chinese Academy Of Agricultural Sciences; Yu, John; SONG, GUOLI - Chinese Academy Of Agricultural Sciences

Submitted to: Molecular Genetics and Genomics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/5/2023
Publication Date: 4/7/2023
Citation: Dai, Y., Liu, S., Zuo, D., Wang, Q., Lu, L., Zhang, Y., Cheng, H., Yu, J., Song, G. 2023. Identification of MYB gene family and functional analysis of GhMYB4 in cotton (Gossypium spp.). Molecular Genetics and Genomics. 298:755–766. https://doi.org/10.1007/s00438-023-02005-5.
DOI: https://doi.org/10.1007/s00438-023-02005-5

Interpretive Summary: Cottonseed is an important oil and protein resource but it cannot be fully utilized due to the presence of toxic gossypol in the seed pigment glands. Although previous studies have shown genetic control of the gland development, knowledge is lacking in the roles of transcription factors (TFs) in pigment glands. One large gene family, called myeloblastosis (MYB) TFs, involve many biological processes including cotton fiber development. In this first systematic analysis of MYB genes in cotton gland development, 646 MYB members were identified in the Upland cotton genome. The transcriptome data were developed and analyzed for gene expression between three pairs of glanded and glandless cotton lines. Results from the analysis shed light into the roles of GhMYBs in the development of cotton pigment glands. The candidate genes would provide valuable tools for functional analysis of MYB genes in cotton gossypol gland formation. Effective utilization of the new information would lead to the genetic engineering of glanded cotton plants with glandless cottonseed.

Technical Abstract: Myeloblastosis (MYB) transcription factors (TFs) form a large gene family involved in a variety of biological processes in plants. Although MYB genes are characterized in some plant species, little is known about their roles in the development of cotton pigment glands. In this study, 646 MYB members were identified in the Gossypium hirsutum genome and they were classified into four distinct groups, namely 1R-MYB, 2R-MYB, 3R-MYB and 4R-MYB, respectively, based on the number of MYB repeats (R). Evolutionary analysis of MYB genes in G. hirsutum revealed that the expansion of the GhMYB family was mainly due to fragment duplication and most GhMYB genes underwent purification selection during cotton evolution. Eight differentially expressed GhMYB genes were identified by screening transcriptome data of three pairs of glanded and glandless cotton lines. Of these, four were selected as candidate genes for cotton pigment gland formation by qRT-PCR assay. Analysis of the cis-acting elements showed that the candidate genes all contained plant hormone response related elements, which may involve the specific hormone regulation. The potential protein interaction network derived from this study suggests that these genes may have indirect interaction with GhMYC2-like, a key regulator of pigment gland formation. The 646 MYB genes identified in G. hirsutum were valuable tools to analyze phylogenetic and evolutionary relationships, transcript expression patterns, cis-acting elements, and potential protein interaction network. Our study was the first systematic analysis of MYB genes in cotton pigment gland development, providing candidate genes for further study on the roles of cotton MYB genes in pigment gland formation and future crop plant improvement.