Programmed proteome response for drought avoidance/tolerance in the root of a C(3) xerophyte (wild watermelon) under water deficits.
Programmed proteome response for drought avoidance/tolerance in the root of a C(3) xerophyte (wild watermelon) under water deficits.
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DOI：
10.1093/pcp/pcm180
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发表时间：
2007-12
影响因子：
4.9
通讯作者：
K. Yoshimura;A. Masuda;M. Kuwano;A. Yokota;K. Akashi
中科院分区：
文献类型：
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作者：
K. Yoshimura;A. Masuda;M. Kuwano;A. Yokota;K. Akashi
水分供应是陆生植物生长和生态分布的关键决定因素。尽管一些旱生植物在其高度发达的根结构和对干旱环境的成功适应方面是独一无二的，但实际上对这种适应的分子机制一无所知。在这里，我们报道了野生西瓜（Citrullus lanatus sp.）的生理和分子反应，它表现出非常高的抗旱性。在干旱胁迫初期，野生西瓜根系发育较灌水植株显著增强，表明野生西瓜启动了从深层土壤吸收水分的抗旱机制。与此一致的是，比较蛋白质组学分析显示，干旱胁迫早期诱导的许多蛋白质参与了根系形态发生和碳氮代谢，这可能通过促进根系生长来避免干旱。另一方面，木质素合成相关蛋白和分子伴侣蛋白主要在干旱胁迫后期被诱导，它们可能分别具有增强物理干燥耐受性和维持蛋白质完整性的功能。我们的研究结果表明，在干旱胁迫的过程中，这种旱生植物通过以一种暂时程序化的方式调节其根蛋白质组，将生存策略从躲避干旱转变为耐旱。该研究为植物根系中参与逆境适应的复杂分子网络提供了新的见解。
Water availability is a critical determinant for the growth and ecological distribution of terrestrial plants. Although some xerophytes are unique regarding their highly developed root architecture and the successful adaptation to arid environments, virtually nothing is known about the molecular mechanisms underlying this adaptation. Here, we report physiological and molecular responses of wild watermelon (Citrullus lanatus sp.), which exhibits extraordinarily high drought resistance. At the early stage of drought stress, root development of wild watermelon was significantly enhanced compared with that of the irrigated plants, indicating the activation of a drought avoidance mechanism for absorbing water from deep soil layers. Consistent with this observation, comparative proteome analysis revealed that many proteins induced in the early stage of drought stress are involved in root morphogenesis and carbon/nitrogen metabolism, which may contribute to the drought avoidance via the enhancement of root growth. On the other hand, lignin synthesis-related proteins and molecular chaperones, which may function in the enhancement of physical desiccation tolerance and maintenance of protein integrity, respectively, were induced mostly at the later stage of drought stress. Our findings suggest that this xerophyte switches survival strategies from drought avoidance to drought tolerance during the progression of drought stress, by regulating its root proteome in a temporally programmed manner. This study provides new insights into the complex molecular networks within plant roots involved in the adaptation to adverse environments.