GaMYB85, an R2R3 MYB gene, in transgenic Arabidopsis plays an important role in drought tolerance

Abstract

BackgroundMYB transcription factors (TFs) are one of the largest families of TFs in higher plants and are involved in diverse biological, functional, and structural processes. Previously, very few functional validation studies on R2R3 MYB have been conducted in cotton in response to abiotic stresses. In the current study, GaMYB85, a cotton R2R3 MYB TF, was ectopically expressed in Arabidopsis thaliana (Col-0) and was functionally characterized by overexpression in transgenic plants.ResultsThe in-silico analysis of GaMYB85 shows the presence of a SANT domain with a conserved R2R3 MYB imperfect repeat. The GaMYB85 protein has a 257-amino acid sequence, a molecular weight of 24.91 kD, and an isoelectric point of 5.58. Arabidopsis plants overexpressing GaMYB85 exhibited a higher seed germination rate in response to mannitol and salt stress, and higher drought avoidance efficiency than wild-type plants upon water deprivation. These plants had notably higher levels of free proline and chlorophyll with subsequent lower water loss rates and higher relative water content. Germination of GaMYB85 transgenics was more sensitive to abscisic acid (ABA) and extremely liable to ABA-induced inhibition of primary root elongation. Moreover, when subjected to treatment with different concentrations of ABA, transgenic plants with ectopically expressed GaMYB85 showed reduced stomatal density, with greater stomatal size and lower stomatal opening rates than those in wild-type plants. Ectopic expression of GaMYB85 led to enhanced transcript levels of stress-related marker genes such as RD22, ADH1, RD29A, P5CS, and ABI5. ConclusionsOur results indicate previously unknown roles of GaMYB85, showing that it confers good drought, salt, and freezing tolerance, most probably via an ABA-induced pathway. These findings can potentially be exploited to develop improved abiotic stress tolerance in cotton plants.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-017-1078-3) contains supplementary material, which is available to authorized users.

Coordinated mechanisms of leaves and roots in response to drought stress underlying full-length transcriptome profiling in Vicia sativa L

“…TFs, as master regulators of many stress-responsive genes, are potential genomic candidates for enhancing tolerance to abiotic stresses such as drought because of their role in enabling plants to withstand unfavourable environments [12,69]. It is now well established that several TF families, including bZIP (mainly AREB/ABF), AP2/ERF, NAC, bHLH, WRKY, and MYB, are key regulators that participate in various abiotic stresses [5,[70][71][72]. Among AREB/ABF subfamily genes in Arabidopsis, the expression of four AREB/ABF TFs (ABF1, ABF3, AREB1/ABF2 and AREB2/ABF4) was induced by abiotic stresses in vegetative tissues; except for ABF1, the remaining TFs were significantly induced both by osmotic and ABA stresses such as dehydration, and ABF2 is also likely involved in glucose signalling [56,73,74].…”

The lre‐miR159a‐LrGAMYB pathway mediates resistance to grey mould infection in Lilium regale

“…Each bar shows the mean ± SE of triplicate assays. * or ** indicates a statistically significant difference relative to the value at 0 hr for each gene at p < .05 or .01, respectively involved in plant development and metabolism (Alonso-Peral et al, 2010;Sheldon et al, 2001) and response to pathogens and abiotic stress (Yang et al, 2014;Butt et al, 2017). Moreover, studies have revealed that MYB transcriptome factors participate in response to B. cinerea.…”

Functional Characterization of the Versatile MYB Gene Family Uncovered Their Important Roles in Plant Development and Responses to Drought and Waterlogging in Sesame

“…Furthermore, Yin et al [ 22 ] showed that OsMYBR1 that was isolated from Oryza sativa improves drought tolerance of transgenic plants through the up-regulation of stress-related genes and the accumulation of osmoprotectants. Similarly, Butt et al [ 23 ] demonstrated that GaMYB85 confers good drought tolerance in Gossypium arboreum , most probably via an ABA-induced pathway. Altogether, these evidences demonstrated the versatility and importance of this gene family in plants.…”