铝（Al）毒害和干旱胁迫是酸性土壤上作物生产的主要限制因子。我们的前期研究结果表明，聚乙二醇（PEG 6000）模拟的干旱胁迫通过降低细胞壁孔隙大小而降低了菜豆根尖Al含量，从而提高了植物耐铝性，而转录分析揭示细胞壁木葡聚糖转移酶/水解酶（XTH）家族两个基因成员PvXTH9和PvXTHb可能在细胞壁孔隙结构调节中起到关键作用。本项目拟在前期研究的基础上，进一步利用Al敏感菜豆基因型，结合生理、生化、分子、遗传及细胞生物学等手段，从不同层面进行深入研究，并详细分析PvXTH9和PvXTHb基因在响应铝和干旱胁迫中的分子调控机制，同时发掘该调控网络中的PvXTH9和PvXTHb上游调控基因并分析其可能的分子调控机制。为进一步明确细胞壁调节在调控植物铝毒害和干旱胁迫中的分子作用机制，最终选育适应多重胁迫的酸性土壤上生长的作物新品种提供科学理论依据。

Aluminum (Al) toxicity and drought stress are two major limiting factors for crop production in acid soils. We previously have demonstrated that polyethylene glycol (PEG 6000)-simulated drought stress reduced aluminum accumulation in root tips by alteration of cell wall porosity, and thus improved aluminum resistance in common bean (Phaseolus vulgaris), further transcriptome analysis revealed that the expression of two xyloglucan endotransglucosylase/hydrolase genes PvXTH9 and PvXTHb may play crucial roles in the modification of cell wall porosity. To better understand the role of PvXTH9 and PvXTHb in the adaptation of aluminum toxicity and drought stress, the present study will clarify the molecular regulation mechanism and potential network of PvXTH9 and PvXTHb in the alteration of wall structure and thus Al accumulation in cell wall under aluminum toxicity and drought stress by combination of the genetic, physiological, biochemical, molecular and cellular approaches.