Organ-specific metabolic responses to drought in Pinus pinaster Ait

• Published in: Plant physiology and biochemistry Vol. 102; pp. 17 - 26
• Main Authors: de Miguel, Marina, Guevara, M. Ángeles, Sánchez-Gómez, David, de María, Nuria, Díaz, Luis Manuel, Mancha, Jose A., Fernández de Simón, Brígida, Cadahía, Estrella, Desai, Nalini, Aranda, Ismael, Cervera, María-Teresa
• Format: Journal Article
• Language: English
• Published: France Elsevier Masson SAS 01-05-2016; Elsevier
• Subjects: Aerial organs; Drought; Genotype; Heterophylly; Life Sciences; Malate Dehydrogenase - metabolism; Metabolic profiling; Organ Specificity; Pinus - metabolism; Pinus pinaster; Plant Proteins - metabolism; Plant Roots - metabolism; Root; Stress, Physiological; Transcription Factors - metabolism; Water - metabolism; Metabolic profiling; Pinus pinaster; Heterophylly; Root; Genotype; Aerial organs; Drought; heterophylly; drought; root; pinus pinaster; aerial organs; metabolic profiling; genotype
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2016.02.013

Drought is an important driver of plant survival, growth, and distribution. Water deficit affects different pathways of metabolism, depending on plant organ. While previous studies have mainly focused on the metabolic drought response of a single organ, analysis of metabolic differences between organs is essential to achieve an integrated understanding of the whole plant response. In this work, untargeted metabolic profiling was used to examine the response of roots, stems, adult and juvenile needles from Pinus pinaster Ait. full-sib individuals, subjected to a moderate and long lasting drought period. Cyclitols content showed a significant alteration, in response to drought in all organs examined, but other metabolites increased or decreased differentially depending on the analyzed organ. While a high number of flavonoids were only detected in aerial organs, an induction of the glutathione pathway was mainly detected in roots. This result may reflect different antioxidant mechanisms activated in aerial organs and roots. Metabolic changes were more remarkable in roots than in the other organs, highlighting its prominent role in the response to water stress. Significant changes in flavonoids and ascorbate metabolism were also observed between adult and juvenile needles, consistent with previously proven differential functional responses between the two developmental stages. Genetic polymorphisms in candidate genes coding for a Myb1 transcription factor and a malate dehydrogenase (EC 1.1.1.37) were associated with different concentration of phenylalanine, phenylpropanoids and malate, respectively. The results obtained will support further research on metabolites and genes potentially involved in functional mechanisms related to drought tolerance in trees.
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•Organ-specific metabolic changes were detected during acclimation to water deprivation.•Sugars, aminoacids and lipids increased more in roots than in aerial organs.•Metabolic changes suggest diverse antioxidant mechanisms for above and below ground organs.•Flavonoid concentration varied with the ontogenic stage of needles.•Association between candidate genes and target compounds under water shortage was detected.