茶树对铝有独特响应，适量的铝能促进茶树根系生长。根系生长与细胞壁扩展关键因子扩展蛋白（Expansins，EXPs）和木葡聚糖内转糖苷酶/水解酶（XTHs）密切相关。本项目主要就EXPs和XTHs在铝促进茶树根系生长过程中的分子响应机制开展研究。以铝累积能力显著差异的两个茶树品种为研究对象，采用组织培养、同源克隆、XTHs酶活性同位素检测技术等，研究铝对参与半纤维素多糖代谢的EXPs基因及合成细胞壁重构关键酶的XTHs基因的表达特性、细胞定位、EXPs的积累量及动态分布、XTHs酶活性等的影响，探讨EXPs和XTHs对铝的响应分子机制；同时采用组培技术，利用生长素合成抑制剂、极性运输抑制剂等手段进一步探讨铝、生长素、EXPs和XTHs间的相互作用分子机制。阐明铝促进茶树根系生长过程中通过生长素对细胞壁松驰扩展关键因子EXPs和XTHs的调控机制。为进一步研究茶树铝营养特性提供理论基础。

Tea plants have the distinctively response to the aluminium(Al) on promoting the root growth. The Expansins and XTHs have close relation with the root growth. This study demonstrates that how the Expansins and XTHs show their response to promote the root growth regulation with presence of Al in tea plant. Two different Al accumulated tea plant varieties are chosen as the study materials, and the homologous cloning technology and the H isotope XTH enzyme assay was applied in this study. In order to make clear the effect of the Expansins and XTHs on the root growth, the expression characteristics of the Expansins and XTHs, the accumulation of the Expansin protein in the root cell wall, the XTH enzyme activity has been accessed. Futher the auxin is the most important factor to the root growth and could regulate the genes express of Expansins and XTHs. In addition to investigate, the synthesis inhibitors and the polarity transportation inhibitors of auxin will be applied to make clear the relationship among the Al, auxin, Expansins and XTHs. This study was able to make clear the regulation mechanism to the effect of Al on the auxin and the cell wall moderation on loosen and enlargement. In future this findings could leads the theoretical basis for the further study of Al nutrition in tea plant.