Zhang Ji-Yi, Cruz DE Carvalho Maria H, Torres-Jerez Ivone, Kang Yun, Allen Stacy N, Huhman David V, Tang Yuhong, Murray Jeremy, Sumner Lloyd W, Udvardi Michael K
Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK, 73401, USA.
Plant Cell Environ. 2014 Nov;37(11):2553-76. doi: 10.1111/pce.12328. Epub 2014 May 11.
Medicago truncatula is a model legume forage crop native to the arid and semi-arid environments of the Mediterranean. Given its drought-adapted nature, it is an ideal candidate to study the molecular and biochemical mechanisms conferring drought resistance in plants. Medicago plants were subjected to a progressive drought stress over 14 d of water withholding followed by rewatering under controlled environmental conditions. Based on physiological measurements of plant water status and changes in morphology, plants experienced mild, moderate and severe water stress before rehydration. Transcriptome analysis of roots and shoots from control, mildly, moderately and severely stressed, and rewatered plants, identified many thousands of genes that were altered in expression in response to drought. Many genes with expression tightly coupled to the plant water potential (i.e. drought intensity) were identified suggesting an involvement in Medicago drought adaptation responses. Metabolite profiling of drought-stressed plants revealed the presence of 135 polar and 165 non-polar compounds in roots and shoots. Combining Medicago metabolomic data with transcriptomic data yielded insight into the regulation of metabolic pathways operating under drought stress. Among the metabolites detected in drought-stressed Medicago plants, myo-inositol and proline had striking regulatory profiles indicating involvement in Medicago drought tolerance.
蒺藜苜蓿是一种模式豆科牧草作物,原产于地中海的干旱和半干旱环境。鉴于其适应干旱的特性,它是研究植物抗旱分子和生化机制的理想候选者。在可控环境条件下,对蒺藜苜蓿植株进行了为期14天的逐步干旱胁迫处理,即停止浇水,随后再浇水。根据对植物水分状况的生理测量和形态变化,植株在复水前经历了轻度、中度和重度水分胁迫。对对照、轻度、中度和重度胁迫以及复水植株的根和地上部分进行转录组分析,鉴定出数千个因干旱而表达发生改变的基因。鉴定出许多表达与植物水势(即干旱强度)紧密相关的基因,表明它们参与了蒺藜苜蓿的干旱适应反应。对干旱胁迫植株的代谢物分析揭示,根和地上部分存在135种极性化合物和165种非极性化合物。将蒺藜苜蓿的代谢组学数据与转录组学数据相结合,有助于深入了解干旱胁迫下代谢途径的调控。在干旱胁迫的蒺藜苜蓿植株中检测到的代谢物中,肌醇和脯氨酸具有显著的调控特征,表明它们参与了蒺藜苜蓿的耐旱性。