Systematic biology analysis on photosynthetic carbon metabolism of maize leaf following sudden heat shock under elevated CO(2)

Plants would experience more complex environments, such as sudden heat shock (SHS) stress combined with elevated CO(2) in the future, and might adapt to this stressful condition by optimizing photosynthetic carbon metabolism (PCM). It is interesting to understand whether this acclimation process would be altered in different genotypes of maize under elevated CO(2), and which metabolites represent key indicators reflecting the photosynthetic rates (P(N)) following SHS. Although B76 had greater reduction in P(N) during SHS treatment, our results indicated that P(N) in genotype B76, displayed faster recovery after SHS treatment under elevated CO(2) than in genotype B106. Furthermore, we employed a stepwise feature extraction approach by partial linear regression model. Our findings demonstrated that 9 key metabolites over the total (35 metabolites) can largely explain the variance of P(N) during recovery from SHS across two maize genotypes and two CO(2) grown conditions. Of these key metabolites, malate, valine, isoleucine, glucose and starch are positively correlated with recovery pattern of P(N). Malate metabolites responses to SHS were further discussed by incorporating with the activities and gene expression of three C(4) photosynthesis-related key enzymes. We highlighted the importance of malate metabolism during photosynthesis recovery from short-term SHS, and data integration analysis to better comprehend the regulatory framework of PCM in response to abiotic stress.