Ectopic Expression of a Heterologous Glutaredoxin Enhances Drought Tolerance and Grain Yield in Field Grown Maize

Abstract

Drought stress is a major constraint in global maize production, causing almost 30–90% of the yield loss depending upon growth stage and the degree and duration of the stress. Here, we report that ectopic expression of Arabidopsis glutaredoxin S17 (AtGRXS17) in field grown maize conferred tolerance to drought stress during the reproductive stage, which is the most drought sensitive stage for seed set and, consequently, grain yield. AtGRXS17-expressing maize lines displayed higher seed set in the field, resulting in 2-fold and 1.5-fold increase in yield in comparison to the non-transgenic plants when challenged with drought stress at the tasseling and silking/pollination stages, respectively. AtGRXS17-expressing lines showed higher relative water content, higher chlorophyll content, and less hydrogen peroxide accumulation than wild-type (WT) control plants under drought conditions. AtGRXS17-expressing lines also exhibited at least 2-fold more pollen germination than WT plants under drought stress. Compared to the transgenic maize, WT controls accumulated higher amount of proline, indicating that WT plants were more stressed over the same period. The results present a robust and simple strategy for meeting rising yield demands in maize under water limiting conditions.

CGFS‐type glutaredoxin mutations reduce tolerance to multiple abiotic stresses in tomato

“…Indeed, chloroplastic A. thaliana AtS14 and AtS16 are involved in photosynthesis, and their loss of function reduces photosynthesis activity under stress conditions (Rey et al 2017). Reduced photosynthesis rate and subsequently vegetative growth in double and triple mutants lacking S14 and S16 could have reduced water consumption, helping the seedlings to survive under drought stress conditions (Hu et al 2017; Tamang et al 2021). However, additional mechanistic studies are required to unravel how s14 and s16 single, double and triple mutants reduced H 2 O 2 accumulation and drought sensitivity.…”

“…Various single, double, and triple mutant lines of tomato CGFS-type SlGRXs were generated and exposed to multiple environmental stresses, including heat, chilling, drought, cadmium (Cd) toxicity, low nutrient and short photoperiod, to address possible functions for each gene as well as their interactions. Based on our previous research findings on GRXS17 (Hu et al 2015(Hu et al , 2017Sprague 2018;Tamang et al 2021;Wu et al 2012Wu et al , 2017, we hypothesized that due to the reduced antioxidant activities, the Slgrxs mutants would be more sensitive than the wild-type plants. Based on the performance and susceptibility of each mutant line under different abiotic stresses, novel functions for each of the CGFS-type GRX genes were proposed.…”

Genome-Wide Association Analysis for Candidate Genes Contributing to Kernel-Related Traits in Maize

“…Another gene GRMZM2G169820 (M9), which was annotated as ARF21 and interacted with some AUX/IAA-related genes ( AUX27, IAA10 , and IAA24 ), was associated with the root node and root length in maize (Wang, 2016 ). Furthermore, the candidate gene GRMZM2G113418 (M13) enhanced drought tolerance and grain yield in field-grown maize and regulated maize inflorescence meristem development via redox control of TGA transcriptional activity (Mamoru et al, 2003 ; Lupini et al, 2016 ; Tamang et al, 2021 ; Yang et al, 2021 ); also, it interacted with NRT1 and NRT2.2 , responding to nitrate provision and transport in maize and Arabidopsis ( Figure 5 , Supplementary Table S7 ).…”

Comparative transcriptomic reveals the molecular mechanism of maize hybrid Zhengdan538 in response to water deficit

“…Drought stress is a major abiotic stress factor that limits plant growth and causes dramatic yield losses in maize. Around 30%–90% of the yield loss depends on a particular plant growth stage and the degree of the drought stress (Tamang et al, 2021). Breeding new maize varieties with high levels of drought tolerance is considered to be an effective approach to solve the drought problem at present.…”