Metabolic Response Research On Maize To The Combined Drought And Heat Stress

Abiotic stress such as drought and heat affect crop growth seriously. Abiotic stress is an important factor leading to reduction of global crop output. Under stress conditions, plants could build a new steady state by adjusting metabolic pathways, in order to adapt to their growth, and to ensure normal physiological activities. Inspect the possible metabolic cross mechanisms between drought and heat stress is important for explaining the mechanism of plants response to drought and heat stress and then providing a possible target in the process of plant breeding for multi-resistance in future.The response and dynamic characteristics of metabolites in maize leaves under drought stress, heat stress and the combined stress were studied by using maize based on metabolomics technology platform. The change regulations in maize biomass, photosynthetic characteristics and reflectance spectral characteristics were also analyzed. The results showed that PCA basically distinguished the polar and non-polar metabolites profiles in maize leaves from drought stress, heat stress and dual stress compared to control group. Metabolites distinct differences include glucose, fructose, sucrose, asparagine, choline, fatty acids and fatty alcohols. ANOVA showed that metabolites responded to dual stress and two types of single stress existed overlap and specificity significantly. Physiological response of maize also existed overlap and specificity under drought stress, heat stress and dual stress. The analysis of metabolic pathways and physiological functions based on glucose metabolism, amino acid metabolism and lipid metabolism suggested that dual stress was different from single drought and heat stress. The dual stress was a new type of stress. Meanwhile, the biomass, nutrient element content and reflectance spectral characteristics of maize responded under single drought and heat stress regularly.