Poplar trees reconfigure the transcriptome and metabolome in response to drought in a genotype- and time-of-day-dependent manner

Abstract

BackgroundDrought has a major impact on tree growth and survival. Understanding tree responses to this stress can have important application in both conservation of forest health, and in production forestry. Trees of the genus Populus provide an excellent opportunity to explore the mechanistic underpinnings of forest tree drought responses, given the growing molecular resources that are available for this taxon. Here, foliar tissue of six water-deficit stressed P. balsamifera genotypes was analysed for variation in the metabolome in response to drought and time of day by using an untargeted metabolite profiling technique, gas chromatography/mass-spectrometry (GC/MS).ResultsSignificant variation in the metabolome was observed in response the imposition of water-deficit stress. Notably, organic acid intermediates such as succinic and malic acid had lower concentrations in leaves exposed to drought, whereas galactinol and raffinose were found in increased concentrations. A number of metabolites with significant difference in accumulation under water-deficit conditions exhibited intraspecific variation in metabolite accumulation. Large magnitude fold-change accumulation was observed in three of the six genotypes. In order to understand the interaction between the transcriptome and metabolome, an integrated analysis of the drought-responsive transcriptome and the metabolome was performed. One P. balsamifera genotype, AP-1006, demonstrated a lack of congruence between the magnitude of the drought transcriptome response and the magnitude of the metabolome response. More specifically, metabolite profiles in AP-1006 demonstrated the smallest changes in response to water-deficit conditions.ConclusionsPathway analysis of the transcriptome and metabolome revealed specific genotypic responses with respect to primary sugar accumulation, citric acid metabolism, and raffinose family oligosaccharide biosynthesis. The intraspecific variation in the molecular strategies that underpin the responses to drought among genotypes may have an important role in the maintenance of forest health and productivity.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-015-1535-z) contains supplementary material, which is available to authorized users.

SWAPDT: A method for Short-time Withering Assessment of Probability for Drought Tolerance in Camellia sinensis validated by targeted metabolomics

“…The results also showed an increase in the levels of isoleucine in the DT cultivars while aspartic acid levels were lower in the DT. A study on the drought response of Poplar trees found that isoleucine had the highest fold increase in DT Poplar trees as compared to the DS under drought stress (Hamanishi et al, 2015). This is in agreement with the results obtained in this study.…”

“…disrupts plant metabolism resulting in metabolic pathway reconfiguration, ensuring plant survival (Hamanishi et al, 2015). Plants have established innumerable strategies in response to drought (Ogbaga et al, 2014).…”

A molecular approach to drought‐induced reduction in leaf CO2 exchange in drought‐resistant Quercus ilex

“…High variability in the expression of TCA‐cycle genes were also observed within Populus balsamífera genotypes subjected to drought. The leaves from drought‐stressed plants showed induction or repression in CS and MD genes depending on the genotype analyzed (Hamanishi et al ).…”

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