The bHLH transcription factor AhbHLH112 improves the drought tolerance of peanut

Abstract

Background Basic helix-loop-helix (bHLH) transcription factors (TFs) are one of the largest gene families in plants. They regulate gene expression through interactions with specific motifs in target genes. bHLH TFs are not only universally involved in plant growth but also play an important role in plant responses to abiotic stress. However, most members of this family have not been functionally characterized. Results Here, we characterized the function of a bHLH TF in the peanut, AhHLH112, in response to drought stress. AhHLH112 is localized in the nucleus and it was induced by drought stress. The overexpression of this gene improves the drought tolerance of transgenic plants both in seedling and adult stages. Compared to wild-type plants, the transgenic plants accumulated less reactive oxygen species (ROS), accompanied by increased activity and transcript levels of antioxidant enzymes (superoxide dismutase, peroxidase and catalase). In addition, the WT plants demonstrated higher MDA concentration levels and higher water loss rate than the transgenic plants under drought treatment. The Yeast one-hybrid result also demonstrates that AhbHLH112 directly and specifically binds to and activates the promoter of the peroxidase (POD) gene. Besides, overexpression of AhHLH112 improved ABA level under drought condition, and elevated the expression of genes associated with ABA biosynthesis and ABA responding, including AtNCED3 and AtRD29A. Conclusions Drawing on the results of our experiments, we propose that, by improving ROS-scavenging ability, at least in part through the regulation of POD -mediated H2O2 homeostasis, and possibly participates in ABA-dependent stress-responding pathway, AhbHLH112 acts as a positive factor in drought stress tolerance.

The IbPYL8–IbbHLH66–IbbHLH118 complex mediates the abscisic acid‐dependent drought response in sweet potato

“…Plants have evolved complex regulatory hormonal signaling networks to respond and adapt to drought conditions. ABA has emerged as a crucial regulator of the drought response (C. Li et al ., 2021; J. Li et al ., 2021; Q. Li et al ., 2021). bHLH TFs are involved in regulating ABA signaling to help plants cope with drought stress (Hao et al ., 2021).…”

Genome-Wide Identification of Potential mRNAs in Drought Response in Wheat (Triticum aestivum L.)

“…The study showed that the overexpression of SBP family proteins imparts abiotic tolerance to different plants [ 44 ]. bHLH family protein was identified as a homologue of TraesCS2D02G000200 in Utricularia gibba and Phytochrome interacting factor 3-like 6 which is one of the bHLH family proteins was found as a homologue of the same gene in Arabidopsis thaliana [ 45 ]. Characterize the function of a bHLH transcription factor (AhHLH112) in drought conditions.…”

Abiotic stress enhancement tools for improving crop tolerance

“…Results depicted these genes remarkably retaliated to water deficit and ABA in roots and/or leaves. The work was useful in directing the useful depiction and enhanced drought-resilient germplasms in peanuts (Li et al, 2021). Heterologous overexpression of Arabidopsis ANAC042/AtJUB1 in tomato (S. lycopersicum) and Arabidopsis enhanced abiotic stress resilience in these plants (Alshareef et al, 2019).…”