SiMYB19 from Foxtail Millet (Setaria italica) Confers Transgenic Rice Tolerance to High Salt Stress in the Field

Abstract

Salt stress is a major threat to crop quality and yield. Most experiments on salt stress-related genes have been conducted at the laboratory or greenhouse scale. Consequently, there is a lack of research demonstrating the merit of exploring these genes in field crops. Here, we found that the R2R3-MYB transcription factor SiMYB19 from foxtail millet is expressed mainly in the roots and is induced by various abiotic stressors such as salt, drought, low nitrogen, and abscisic acid. SiMYB19 is tentatively localized to the nucleus and activates transcription. It enhances salt tolerance in transgenic rice at the germination and seedling stages. SiMYB19 overexpression increased shoot height, grain yield, and salt tolerance in field- and salt pond-grown transgenic rice. SiMYB19 overexpression promotes abscisic acid (ABA) accumulation in transgenic rice and upregulates the ABA synthesis gene OsNCED3 and the ABA signal transduction pathway-related genes OsPK1 and OsABF2. Thus, SiMYB19 improves salt tolerance in transgenic rice by regulating ABA synthesis and signal transduction. Using rice heterologous expression analysis, the present study introduced a novel candidate gene for improving salt tolerance and increasing yield in crops grown in saline-alkali soil.

Genome-Wide Identification and Transcriptional Analysis of the MYB Gene Family in Pearl Millet (Pennisetum glaucum)

“…In crops, rice OsMYB60 and OsMYB55 and wheat TaMYB31 function as key regulators, positively improving resilience to water stress [16][17][18]. Notably, a foxtail millet MYB gene, SiMYB19, improves salt tolerance in transgenic rice by promoting abscisic acid (ABA) accumulation, thus, upregulating ABA-dependent stress responsive genes [19].…”

Heterologous Expressions of foxtail millet (Seteria italica) mitogen-activated protein kinase kinase (SiMKK) group A genes regulate root development under salt stress in Arabidopsis thaliana

“…SiMYB16 and SiMYB19 were both upregulated by salt stress. Overexpression of SiMYB16 and SiMYB19 enhanced salt tolerance of plants by regulating the biosynthesis of lignin and ABA signal transduction respectively (Yu et al 2023;Xu et al 2022). Salt stress resulted in decreased biomass, decreased relative water content and membrane damage in foxtail millet (Rathinapriya et al 2020).…”

SiMYBS3, Encoding a Setaria italica Heterosis-Related MYB Transcription Factor, Confers Drought Tolerance in Arabidopsis

“…For example, overexpression of the foxtail millet SiMYB3 gene enhanced tolerance to low-nitrogen stress in rice [ 37 ]. Overexpression of SiMYB19 in rice enhanced salt resistance [ 38 ] and overexpression of SiMYB56 conferred drought tolerance [ 39 ]. In our study, drought-induced upregulation of SiMYBS3 expression in Zhangza 19 and overexpression of SiMYBS3 in Arabidopsis conferred drought tolerance.…”