OsMYB45 plays an important role in rice resistance to cadmium stress

Abstract

Cadmium (Cd) is one of the most toxic heavy metal elements in nature, and it causes serious damage to plant cells. Here, we report that a transcription factor OsMYB45 is involved in Cd stress response in rice. OsMYB45 is highly expressed in rice leaves, husks, stamens, pistils, and lateral roots, and its expression is induced by Cd stress. OsMYB45 fused to green fluorescent protein localized to the cell nucleus in onion epidermal cells. Mutation of OsMYB45 resulted in hypersensitivity to Cd treatment, and the concentration of HO in the leaves of mutant nearly doubled, while catalase (CAT) activity was halved compared with the wild-type. Moreover, gene expression analysis indicated that OsCATA and OsCATC expression is significantly lower in the mutant than in the wild-type. In addition, overexpression of OsMYB45 in the mutant complemented the mutant phenotype. Taken together, OsMYB45 plays an important role in tolerance to Cd stress in rice.

Genome-Wide Identification and Characterization of Four Gene Families Putatively Involved in Cadmium Uptake, Translocation and Sequestration in Mulberry

“…The mechanisms of the regulation of expression of the HM transporter genes are largely unknown. There are a few transcription factors known to be involved in Cd stress response, such as CaPF1 (an ERF/AP2-like transcription factor), TaHSFA4a (a member of the heat shock transcription factor family), microRNA268 and OsMYB45 ( Tang et al, 2005 ; Donghwan et al, 2009 ; Ding et al, 2017 ; Hu et al, 2017 ). In our study, several transporter genes were shown to contain MYB binding sites and/or heat stress responsive sites in their promoter sequences.…”

Disruption of EARLY LESION LEAF 1, encoding a cytochrome P450 monooxygenase, induces ROS accumulation and cell death in rice

“…In plants, ROS are formed in many distinct reactions, in the cytoplasm as well as different organelles, including chloroplasts, mitochondria, peroxisomes, and apoplasts (Heyno et al, 2008). Overaccumulation of ROS, such as superoxide radicals (O 2 À• ) and hydrogen peroxide (H 2 O 2 ), disrupts the redox balance in cells and results in severe oxidative damage to nucleic acids, proteins, and lipid membranes (Foyer and Noctor, 2005;Hu et al, 2017). In addition, high levels of ROS are closely associated with the occurrence of lesions and PCD, as confirmed in Arabidopsis thaliana (Chai et al, 2015), wheat (Triticum aestivum) (Abou-Attia et al, 2016), and rice (Oryza sativa) (Yang et al, 2017a;Xiao et al, 2018).…”

“…In order to avoid excessive ROS accumulation in cells, plants control ROS levels by the antioxidant defense system, which includes antioxidant enzymes and ascorbic acid (Hu et al, 2011). These antioxidant enzymes include peroxidase ascorbate peroxidase (APX), catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) (Hu et al, 2017). SOD catalyzes the conversion of O 2 À• to H 2 O 2 and provides defense against oxidative stress; POD, APX, and CAT catalyze the conversion of H 2 O 2 to H 2 O in various organelles (Gill and Tuteja, 2010).…”

Impact of Pb on Chlamydomonas reinhardtii at Physiological and Transcriptional Levels

“…Overexpressed AP2 protected plants against oxidative stress induced by trace elements through enhancing the production of APX, GR, and SOD (Tang et al, 2005). Previous studies have also demonstrated that the expression of AP2 and MYB were up-regulated on exposure to trace elements, mutation in MYB gene resulted in the increase of trace element sensitivity, the significant accumulation of H 2 O 2 and decrease of CAT activity in higher plants (Van De Mortel et al, 2008;Ogawa et al, 2009;Hu et al, 2017). Overexpression of bHLH gene increased the sequestration of Cd in plants (Wu et al, 2012).…”