Competition for scarce water resources and the continued effects of global warming exacerbate current constraints on potato crop production. While plants’ response to drought in above-ground tissues has been well documented, the regulatory cascades and subsequent nutritive changes in developing tubers have been largely unexplored. Using the commercial Canadian cultivar “Vigor”, plants were subjected to a gradual drought treatment under high tunnels causing a 4 °C increase in the canopy temperature. Tubers were sampled for RNAseq and metabolite analysis. Approximately 2600 genes and 3898 transcripts were differentially expressed by at least 4-fold in drought-stressed potato tubers, with 75% and 69% being down-regulated, respectively. A further 229 small RNAs were implicated in gene regulation during drought. Expression of several small RNA clusters negatively correlated with expression of their six target patatin genes, suggesting involvement in the regulation of storage proteins during drought. The comparison of protein homologues between Solanum tuberosum L. and Arabidopsis thaliana L. indicated that down-regulated genes were associated with phenylpropanoid and carotenoid biosynthesis. As is indicative of reduced flow through the phenylpropanoid pathway, phenylalanine accumulated in drought-stressed tubers. This suggests that there may be nutritive implications to drought stress occurring during the potato tuber bulking phase in sensitive cultivars.

中文翻译：

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干旱诱导的调控级联及其对发育中马铃薯块茎营养品质的影响

对稀缺水资源的竞争和全球变暖的持续影响加剧了目前对马铃薯作物生产的限制。虽然植物对地上组织干旱的反应已被充分记录，但发育中的块茎中的调节级联反应和随后的营养变化在很大程度上尚未得到探索。使用加拿大商业品种“活力”，植物在高隧道下进行逐渐干旱处理，导致冠层温度升高 4 °C。对块茎进行采样用于 RNAseq 和代谢物分析。大约 2600 个基因和 3898 个转录本在干旱胁迫的马铃薯块茎中差异表达至少 4 倍，分别有 75% 和 69% 被下调。另有 229 个小 RNA 与干旱期间的基因调控有关。几个小 RNA 簇的表达与其六个目标 patatin 基因的表达负相关，表明参与了干旱期间储存蛋白的调节。Solanum tuberosum L. 和Arabidopsis thaliana L. 蛋白质同源物的比较表明下调基因与苯丙烷和类胡萝卜素的生物合成有关。作为通过苯丙烷途径减少的流量的指示，苯丙氨酸在干旱胁迫的块茎中积累。这表明在敏感品种的马铃薯块茎膨大阶段发生的干旱胁迫可能具有营养意义。Solanum tuberosum L. 和Arabidopsis thaliana L. 蛋白质同源物的比较表明下调基因与苯丙烷和类胡萝卜素的生物合成有关。作为通过苯丙烷途径减少的流量的指示，苯丙氨酸在干旱胁迫的块茎中积累。这表明在敏感品种的马铃薯块茎膨大期发生的干旱胁迫可能具有营养意义。Solanum tuberosum L. 和Arabidopsis thaliana L. 蛋白质同源物的比较表明下调基因与苯丙烷和类胡萝卜素的生物合成有关。作为通过苯丙烷途径减少的流量的指示，苯丙氨酸在干旱胁迫的块茎中积累。这表明在敏感品种的马铃薯块茎膨大阶段发生的干旱胁迫可能具有营养意义。