Centre de Recherche Public-Gabriel Lippmann, Department EVA, 41, rue du Brill, L-4422 Belvaux, Luxembourg.
J Exp Bot. 2010 May;61(9):2327-43. doi: 10.1093/jxb/erq060. Epub 2010 Apr 20.
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.
两个安第斯品种组的马铃薯克隆体（Solanum tuberosum L.），称为 Sullu 和 SS2613，具有不同的耐旱表型，在田间试验中暴露于持续增加的干旱胁迫下。在生理水平上，虽然两个克隆体的相对叶片水分含量相似，但渗透势在 Sullu 中较低，并且在干旱期间下降得更强烈。在受干旱胁迫的植物中，与对照植物相比，两个克隆体的块茎产量都减少了约 70%。在干旱开始后几个时间点采集叶片进行马铃薯 cDNA 微阵列和目标代谢物分析。在转录组水平上，Sullu 在断水 28 天后光合作用相关基因已被强烈抑制，在更长的胁迫时间后甚至更强，而在 SS2613 中，只有在土壤干燥 49 天后才发生抑制；同样，碳水化合物相关基因也受到强烈干扰。在代谢物水平上，两个品种之间观察到渗透活性溶质的差异积累；事实上，在 Sullu 中，与 SS2613 相比，干旱胁迫下半乳糖、肌醇、半乳糖醇、脯氨酸和脯氨酸类似物的含量更高。这些结果表明，在叶片水平上，品种之间存在不同的干旱反应，但块茎产量减少相似。先前表现出耐受的克隆体 Sullu 在本实验条件下部分丧失了其耐受性；然而，它能够保持比 SS2613 高三倍的绝对产量。
