Alpha-Linolenic Acid Mediates Diverse Drought Responses in Maize (Zea mays L.) at Seedling and Flowering Stages

Abstract

Water shortage caused by long-term drought is one of the most serious abiotic stress factors in maize. Different drought conditions lead to differences in growth, development, and metabolism of maize. In previous studies, proteomics and genomics methods have been widely used to explain the response mechanism of maize to long-term drought, but there are only a few articles related to metabolomics. In this study, we used transcriptome and metabolomics analysis to characterize the differential effects of drought stress imposed at seedling or flowering stages on maize. Through the association analysis of genes and metabolites, we found that maize leaves had 61 and 54 enriched pathways under seedling drought and flowering drought, respectively, of which 13 and 11 were significant key pathways, mostly related to the biosynthesis of flavonoids and phenylpropanes, glutathione metabolism and purine metabolism. Interestingly, we found that the α-linolenic acid metabolic pathway differed significantly between the two treatments, and a total of 10 differentially expressed genes and five differentially abundant metabolites have been identified in this pathway. Some differential accumulation of metabolites (DAMs) was related to synthesis of jasmonic acid, which may be one of the key pathways underpinning maize response to different types of long-term drought. In general, metabolomics provides a new method for the study of water stress in maize and lays a theoretical foundation for drought-resistant cultivation of silage maize.

Targeted metabolomics reveals fatty acid abundance adjustments as playing a crucial role in drought-stress response and post-drought recovery in wheat

“…Linolenic acid has been found to participate in the synthesis of jasmonic acid during seedling drought and to alleviate drought stress through jasmonic acid signaling. Maize has been shown to tend to use free fatty acids as antioxidant substances to reduce drought-induced damage (Zi et al, 2022). Linolenic acid is also part of photosynthetic membranes, along with other cellular membranes.…”

Spatiotemporal Metabolic Responses to Water Deficit Stress in Distinct Leaf Cell-types of Poplar

“…Linoleate is an unsaturated fatty acid and is part of the chloroplast membrane. An increase in the degree of unsaturation of membrane lipids was associated with improved drought resistance and ROS neutralization (He and Ding, 2020a, Ullah et al, 2022, Zi et al, 2022), which highlights the potential role of fatty acid composition in poplar leaf palisade cells to help mitigate the L-WD stress-related consequences. Looking at leaf physiological parameters during WD stress (Supplementary Figure S1B), compared to E-WD, photosynthesis, leaf conductance, and transpiration rates were improved during L-WD, signifying the possible roles of flavonoids and fatty acids in neutralizing ROS (Jia et al, 2021, Resmi et al, 2015), leading to the observed improved leaf performance during L-WD stress.…”

Metabolic profiles in the xylem sap of Brassica juncea exposed to cadmium

“…Differential genes and metabolites involved in α‐linolenic acid metabolic pathways showed remarkable enrichment in plants exposed to drought and cold (Fu et al, 2016; Lenka et al, 2011). In maize seedling and flowering stages, five differentially abundant metabolites were identified in the α‐linolenic acid metabolic pathway, and differentially expressed genes (DEGs) ACOX3 and LOC were also significantly upregulated under drought stress (Zi et al, 2022). In our study, the α‐linolenic acid metabolic pathway in xylem sap was changed under both 48‐h and 7‐day Cd stress, especially colnelenic acid and 12,13‐EOTrE were significantly upregulated under Cd stress for 7 days.…”