A Cotton MYB Transcription Factor, GbMYB5, is Positively Involved in Plant Adaptive Response to Drought Stress

Abstract

Drought stress negatively affects plant growth and limits plant productivity. Genes functioning in plant responses to drought stress are essential for the development of drought-tolerant crops. Here, we report that an R2R3-type MYB transcription factor gene in Gossypium barbadense, GbMYB5, confers drought tolerance in cotton and transgenic tobacco. Virus-induced gene silencing of GbMYB5 compromised the tolerance of cotton plantlets to drought stress and reduced the post-rewatering water recovery survival rate to 50% as compared with the 90% survival rate in the wild type (WT). Silencing GbMYB5 decreased proline content and antioxidant enzyme activities and increased malondialdehyde (MDA) content in cotton under drought stress. The expression levels of drought-inducible genes NCED3, RD22 and RD26 were not affected by the silencing of GbMYB5. However, GbMYB5-overexpressing tobacco lines displayed hypersensitivity to ABA and improved survival rates as well as reduced water loss rates under drought stress. Furthermore, stomatal size and the rate of opening of stomata were markedly decreased in transgenic tobacco. The overexpression of GbMYB5 enhanced the accumulation of proline and antioxidant enzymes while it reduced production of MDA in transgenic tobacco as compared with the WT under drought stress. The transcript levels of the antioxidant genes SOD, CAT and GST, polyamine biosynthesis genes ADC1 and SAMDC, the late embryogenesis abundant protein-encoding gene ERD10D and drought-responsive genes NCED3, BG and RD26 were generally higher in GbMYB5-overexpressing tobacco than in the WT under drought stress. Collectively, our data suggested that GbMYB5 was positively involved in the plant adaptive response to drought stress.

Functional characterization of MdMYB73 reveals its involvement in cold stress response in apple calli and Arabidopsis

“…Some MYB transcription factors have currently been identifed to involve in the resistant response in many plant species such as Arabidopsis, wheat, tobacco, rice, and soybean plants. For example, OsMYB91 was involved in salt tolerance in rice, while GbMYB5 increased drought tolerance in cotton (Chen et al 2015;Zhu et al 2015).…”

Small RNA and degradome profiling reveals important roles for microRNAs and their targets in tea plant response to drought stress

“…Reactive oxygen species (ROS)‐mediated Ca 2+ signaling also affects plant stomatal movement (Golec and Szarejko ). Changes in the transcriptional levels of hundreds of genes are involved in plant responses to DS and following recovery (RC); most of these genes are regulated by various transcription factors, such as the basic leucine zipper (bZIP), NAC domain‐containing protein (NAC) and myeloblastosis oncoprotein (MYB) (Golldack et al , Chen et al ).…”

Genome-wide identification of cassava R2R3 MYB family genes related to abscission zone separation after environmental-stress-induced abscission

“…AtMYBR1 is suppressed by water stress and wounding, thereby regulating leaf senescence5. GbMYB5 confers drought tolerance in cassava and transgenic tobacco6. MdSIMYB1 from apples is induced by abiotic stresses and plant hormones7.…”