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

Tej Man Tamang,Stuart A Sprague,Frank F White,Sunghun Park,Sanzhen Liu,Tayebeh Kakeshpour

doi:10.3390/ijms22105331

Tej Man Tamang, Stuart A Sprague + Show 4 more

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https://doi.org/10.3390/ijms22105331

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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.

Highlights

The world population is expected to grow to 9.7 billion by 2050, and global food production should be doubled to meet the demand [1,2]
Maize endogenous monothiol glutaredoxin S17, ZmGRXS17, expression was measured in leaf tissue of various inbred lines (B73, B104, A188, and HiIIA) in response to drought stress
The expression pattern of ZmGRXS17 under drought stress was similar across the inbred lines (Supplementary Figure S1a)

Summary

Introduction

The world population is expected to grow to 9.7 billion by 2050, and global food production should be doubled to meet the demand [1,2]. Drought is one of the environmental stresses that affects the quality and quantity of crop production [3,4]. Drought severely affects plant growth and development and, leads to the death of the plant by affecting various physiological and biochemical processes such as photosynthesis, respiration, and nutrient uptake and translocation [5]. It is estimated that drought events will be more frequent, intense, and longer in the agriculturally important areas and pose a serious threat to the food security [3,6,7]. Since 1990, drought has affected almost 2 billion people and has cost the global economy losses of USD 6 to 8 billion annually [7]. Drought impacts maize production and growth from vegetative stages to the reproductive stages [8]

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