Genome-Wide Analysis of Myeloblastosis-Related Genes in Brassica napus L. and Positive Modulation of Osmotic Tolerance by BnMRD107

Abstract

Myeloblastosis (MYB)-related transcription factors comprise a large subfamily of the MYB family. They play significant roles in plant development and in stress responses. However, MYB-related proteins have not been comprehensively investigated in rapeseed (Brassica napus L.). In the present study, a genome-wide analysis of MYB-related transcription factors was performed in rapeseed. We identified 251 Brassica napus MYB (BnMYB)-related members, which were divided phylogenetically into five clades. Evolutionary analysis suggested that whole genome duplication and segmental duplication events have played a significant role in the expansion of BnMYB-related gene family. Selective pressure of BnMYB-related genes was estimated using the Ka/Ks ratio, which indicated that BnMYB-related genes underwent strong purifying selection during evolution. In silico analysis showed that various development-associated, phytohormone-responsive, and stress-related cis-acting regulatory elements were enriched in the promoter regions of BnMYB-related genes. Furthermore, MYB-related genes with tissue or organ-specific, stress-responsive expression patterns were identified in B. napus based on temporospatial and abiotic stress expression profiles. Among the stress-responsive MYB-related genes, BnMRD107 was strongly induced by drought stress, and was therefore selected for functional study. Rapeseed seedlings overexpressing BnMRD107 showed improved resistance to osmotic stress. Our findings not only lay a foundation for further functional characterization of BnMYB-related genes, but also provide valuable clues to determine candidate genes for future genetic improvement of B. napus.

Genome-Wide Analysis of the Type-B Authentic Response Regulator Gene Family in Brassica napus

“…For hormone treatment, five-week-old seedlings of B. napus line ‘J9712′, grown in a light incubator with 22 °C, 16 h light/8 h dark photocycle, were treated with 100 µM ABA, 100 µM kinetin (KT), 500 µM gibberellin (GA), 50 µM indoleacetic acid (IAA), and 10 µM strigolactone (SL). Three replicates of leaves were pooled respectively after 0 h, 1 h, 3 h, 6 h, and 12 h of treatment [ 74 , 75 ]. For osmotic, salt, and drought stresses, the ‘J9712′ seeds were germinated on 1/2 MS medium containing 150 mM mannitol, 150 mM NaCl, or 15% PEG.…”

A Multi-Omics Analysis Revealed the Diversity of the MYB Transcription Factor Family’s Evolution and Drought Resistance Pathways

“…Moreover, Wan constructed a qRT-PCR assay to analyze the expression of GmMYB84 gene, and the results showed that both drought treatment and ABA treatment significantly increased the expression of the gene within 24 h [69]. The analysis of MYBrelated subfamily members in Brassica napus revealed a significant presence of BnMYBrelated genes containing cis-acting elements that displayed responsiveness to various hormones, including abscisic acid and gibberellin [70]. Twenty-one ethylene-responsive element binding-factor-associated amphiphilic repression (EAR) motifs were identified in the potato MYB family [71].…”

Characteristics and Functions of MYB (v-Myb avivan myoblastsis virus oncogene homolog)-Related Genes in Arabidopsis thaliana

“…In Morus alba, a total of 166 MYBs were identified [21]. A number of identifications and studies have also been published on MYB-related genes in other plants, including soybean [22], potato [23], Brassica napus L. [24], populus [9], pepper [25], and sweet osmanthus [26].…”