Physiological and biochemical analyses of novel drought-tolerant maize lines reveal osmoprotectant accumulation at silking stage

Abstract

Drought is one of the most limiting factors in agricultural production worldwide. The aim of this work was to evaluate the per se response to drought stress of three maize (Zea mays L.) semi-inbred lines (CHIH, COAH, and ARZM) during the anthesis and grain filling stages. These semi-inbred lines (BC1S1) are S1 offspring of crosses between drought-tolerant maize and a high-yield line bred by the Centro Internacional de Mejoramiento de Maíz y Trigo (CIMMYT). Materials were evaluated during a 15-d controlled drought and post-drought irrigation reestablishment period. The photosynthetic rate decreased by 50% in CHIH during drought and it recovered after stress was removed. Proline levels increased 2.3 times in COAH during stress and nonsignificant increases were observed in ARZM or CHIH. However, glycine betaine accumulated at 1061-1133 ng mg -1 fresh weight (FW) before stress, but decreased to 879-1000 ng mg -1 FW during drought stress. The trehalose concentration increased 1.8 times in ARZM (5.60 ng mg -1 FW) under drought stress and remained at similar levels in CHIH (6.48 ng mg -1 FW) and COAH (8.63 ng mg -1 FW) before and during drought stress. In contrast, trehalose-6-phosphate decreased 33% to 38% under drought stress in all three BC1S1 entries and recovered its initial levels after irrigation. Grain biomass loss under drought stress was 54% for ARZM, 48.2% for COAH, and only 26.5% for CHIH. These results showed that CHIH, COAH, and ARZM are drought-tolerant and suggest that osmoprotectant accumulation might play a key role in their physiological performance and grain biomass trait.

Maize Production under Drought Stress: Nutrient Supply, Yield Prediction

“…It causes an 8–10% reduction in chlorophyll content during the vegetative stage and 18% reduction during the reproductive stage [ 15 , 16 ]. It also alters genetic properties [ 17 ] and causes yield reduction [ 18 , 19 , 20 , 21 , 22 , 23 ]. Maize yield loss can vary from 30 to 90% depending on the intensity and duration of drought stress.…”

A Versatile Peroxidase from the Fungus Bjerkandera adusta Confers Abiotic Stress Tolerance in Transgenic Tobacco Plants

“…Relative water content (RWC) is a specific tool for the measurement of drought tolerance and gives a credible evaluation of the plant water status [ 28 ]. In fact, RWC estimates the deficit in water level at a given time, which is used to reflect dehydration stress.…”

“…After floating them in deionized water at 4 °C overnight, their rehydrated weight was determined. The dried weight was determined after incubating leaves in an oven at 70 °C during 24 h. Plant RWC (%) was calculated by measuring (fresh weight–dry weight)/(rehydrated weight–dry weight) × (100) [ 28 ].…”

Consequences of Dryland Maize Planting Decisions Under Increased Seasonal Rainfall Variability

“…Changes in rainfall associated with climate variability directly impact crop growth as storms are projected to become more intense with longer periods between rainfall events (Donat et al., 2016; Harrison et al., 2019; Meehl et al., 2007). The stochastic nature of rainfall during the growing season leaves crops susceptible to water stress during critical stages of development and can lead to crop failure (Sah et al., 2020; Salgado‐Aguilar et al., 2020). Small rainfed farms cultivated by single families on plots less than 5 ha represent the most prevalent form of agriculture in sub‐Saharan Africa and are particularly vulnerable to climate variability and change (Samberg et al., 2016).…”