Poster: Molecular & Cellular Plant-Microbe Interactions: Proteomics/Metabolomics/Genomics
Differential metabolome analysis of field-grown maize kernels in response to drought stress
L. YANG (1), J. Fountain (1), X. Ni (2), R. Lee (1), S. Chen (3), B. Scully (2), R. Kemerait (1), B. Guo (2) (1) University of Georgia, U.S.A.; (2) USDA-ARS, U.S.A.; (3) University of Florida, U.S.A.
Drought stress constrains maize kernel development and can exacerbate aflatoxin contamination. In order to identify drought responsive metabolites and explore pathways involved in kernel responses, a metabolomics analysis was conducted on kernels from a drought tolerant line, Lo964, and a sensitive line, B73, with and without drought stress treatment for 7 and 14 days after drought induction beginning 7 days after pollination. Using ultra-performance liquid chromatography coupled with MS/MS, we profiled 445 metabolites covering 42 pathways. Drought stress induced higher accumulation of glycerolipid and phospholipid metabolites, and decreased content of galactolipid, amines and polyamines, amino sugar, and nucleotide sugar metabolites in both lines. However, B73 was found to accumulate fewer metabolites involved in dipeptide and pyrimidine metabolism under drought stress than Lo964. Lo964 also exhibited increases in sphingolipid, sterol, and purine metabolism in comparison to B73. Collectively, higher sugar accumulation, a lower rate of energy metabolism, and elevated lipid and nucleic acid turnover was observed in B73. Conversely, higher amino acid and dipeptide accumulation, a lower TCA cycle rate, and elevated lipid and nucleic acid turnover was observed in Lo964 in response to drought stress. These results suggest that drought sensitivity is associated with differential metabolite accumulation, and diverse metabolic pathways in maize kernels.