Metabolite profiles of maize leaves in drought, heat and combined stress field trials reveal the relationship between metabolism and grain yield

Abstract

The development of abiotic stress-resistant cultivars is of premium importance for the agriculture of developing countries. Further progress in maize (Zea mays) performance under stresses is expected by combining marker-assisted breeding with metabolite markers. In order to dissect metabolic responses and to identify promising metabolite marker candidates, metabolite profiles of maize leaves were analyzed and compared with grain yield in field trials. Plants were grown under well-watered conditions (control) or exposed to drought, heat, and both stresses simultaneously. Trials were conducted in 2010 and 2011 using 10 tropical hybrids selected to exhibit diverse abiotic stress tolerance. Drought stress evoked the accumulation of many amino acids, including isoleucine, valine, threonine, and 4-aminobutanoate, which has been commonly reported in both field and greenhouse experiments in many plant species. Two photorespiratory amino acids, glycine and serine, and myoinositol also accumulated under drought. The combination of drought and heat evoked relatively few specific responses, and most of the metabolic changes were predictable from the sum of the responses to individual stresses. Statistical analysis revealed significant correlation between levels of glycine and myoinositol and grain yield under drought. Levels of myoinositol in control conditions were also related to grain yield under drought. Furthermore, multiple linear regression models very well explained the variation of grain yield via the combination of several metabolites. These results indicate the importance of photorespiration and raffinose family oligosaccharide metabolism in grain yield under drought and suggest single or multiple metabolites as potential metabolic markers for the breeding of abiotic stress-tolerant maize.

LC-HRMS Based Non-Targeted Metabolomic Profiling of Wheat (<I>Triticum aestivum</I> L.) under Post-Anthesis Drought Stress

“…Decreased levels of raffinose of the drought stressed leaves can be accounted to the drought tolerance of the wheat plants (SS8641). Obata et al (2015) also reported lower levels of raffinose and myo-inositol in a tolerant maize genotype and suggested that that these could be due to the use of raffinose family oligosacchardises (RFOs) by the tolerant genotypes as their carbon sources [15].…”

“…Obata et al (2015) opined that promising metabolic traits were stronger in explaining variability in maize grain yield than classical agronomic yield components [15]. Six metabolites namely N-acetyl-glutamic acid, tryptophan, proline, linamarin, pipecolate, malonate and DIBOA-glucoside were identified as potential biomarkers by classical univariate and multivariate analysis.…”

“…Crop yield has shown significant correlation with metabolites under drought [15]. Metabolic composition is highly variable in a wide variety of plants including major crops like wheat [16], rice [17], maize [15], and cassava [14].…”

“…Metabolic composition is highly variable in a wide variety of plants including major crops like wheat [16], rice [17], maize [15], and cassava [14]. These metabolic changes in plants have also occurred due to progressive water deficit conditions accompanied by lower leaf water potentials [18].…”

Comparative Metabolic Response between Cucumber (Cucumis sativus) and Corn (Zea mays) to a Cu(OH)2 Nanopesticide

“…In addition, myo-inositol acts as a scavenger of active oxygen to protect the cellular structures. 28 Obata et al 29 reported that the importance of myo-inositol in plant stress tolerance is related to its function as a precursor of many metabolites involved in abiotic stress tolerance. The reason for the up-regulation of myo-inositol in this study is unclear, but either role will assist adaptation of maize leaves to stress induced by the Cu(OH) 2 nanopesticide.…”