title: Identification of drought-responsive compounds in potato through a combined transcriptomic and targeted metabolite approach.
abstract: Two potato clones (Solanum tuberosum L.) of the Andean cultivar group, called Sullu and SS2613, with different drought-tolerance phenotypes were exposed to a continuously increasing drought stress in a field trial. At the physiological level, while relative leaf water contents were similar in both clones, osmotic potential was lower in Sullu and declined more strongly during drought compared with SS2613. In the drought-stressed plants, tuber yield was reduced by about 70% compared with control plants in both clones. Potato cDNA microarrays and target metabolite analysis were performed on leaves sampled at several time-points after the onset of drought. At the transcriptomic level, photosynthesis-related genes were already strongly repressed in Sullu after 28 d of withholding irrigation and even more strongly after a longer stress duration, whereas, in SS2613, repression occurred only after 49 d of soil drying; similarly, a strong perturbation of carbohydrate-related genes was observed in Sullu. At the metabolite level, differential accumulation of osmotically active solutes was observed between the two cultivars; indeed, in Sullu, contents of galactose, inositol, galactinol, proline, and proline analogues were higher upon drought stress compared with SS2613. These results point to different drought responses in the cultivars at the leaf level, with, however, similar tuber yield reductions. The previously shown tolerant clone Sullu lost part of its tolerance under the experimental conditions used here; it was, however, able to maintain an absolute yield three times higher than SS2613.
authors.affiliation: Centre de Recherche Public-Gabriel Lippmann, Department EVA, 41, rue du Brill, L-4422 Belvaux, Luxembourg. evers@lippman.lu
authors.forename: Danièle
authors.initials: D
authors.lastname: Evers
authors.forename: Isabelle
authors.initials: I
authors.lastname: Lefèvre
authors.forename: Sylvain
authors.initials: S
authors.lastname: Legay
authors.forename: Didier
authors.initials: D
authors.lastname: Lamoureux
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Hausman
authors.forename: Raymundo Oscar Gutierrez
authors.initials: RO
authors.lastname: Rosales
authors.forename: Luz Rosalina Tincopa
authors.initials: LR
authors.lastname: Marca
authors.forename: Lucien
authors.initials: L
authors.lastname: Hoffmann
authors.forename: Merideth
authors.initials: M
authors.lastname: Bonierbale
authors.forename: Roland
authors.initials: R
authors.lastname: Schafleitner
mesh_terms: D055864:Droughts; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D055432:Metabolomics; D011198:Solanum tuberosum / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D014867:Water / Q000378:metabolism
chemical_list: D014867:Water