旱生灌木霸王SAUR30在植物侧根发育及干旱适应中的功能和分子机理研究

侧根的发生在植物吸收水分和养分以适应土壤干旱等逆境过程中起十分关键的作用。侧根发育受生长素的严格调控，位于生长素信号转导途径下游的生长素早期响应基因在侧根的起始与发育过程中发挥重要调控功能。目前，对植物侧根发育及干旱适应分子机制的研究多以中生植物为材料，但其根系并不发达，对水分亏缺较为敏感，并不是发掘相关调控基因的理想材料。本项目拟以侧根十分发达的荒漠旱生灌木霸王为材料，在前期发现其根中生长素早期响应基因ZxSAUR30受渗透胁迫强烈诱导的基础上，采用RNA干扰技术和过量表达分别获得该基因沉默和超表达霸王株系，分析其侧根发育情况及抗旱能力；并借助模式植物拟南芥，利用酵母双杂交、CoIP、ChIP及遗传杂交等分子遗传学方法研究SAUR30的作用机制。以期进一步阐明荒漠植物适应干旱逆境的分子机理，为植物抗逆性育种及荒漠生态保护、恢复和合理利用提供科学依据。

Plant lateral root formation plays important roles in absorbing water and nutrients to adapt to soil environment such as drought. Lateral root growth and development are strictly regulated by auxin. The early auxin response genes downstream of auxin signaling pathway play key roles in the initiation and development of lateral roots. But plants used in these researches were mesophytes with weak drought-tolerant ability, and their roots are not well-developed. In this project, by using the typical xeromorphic shrub Zygophyllum xanthoxylum which has well-developed lateral roots as material, and taking the auxin response gene ZxSAUR30 in response to osmotic stress as breakthrough point, the following experiments would be done to reveal the function and molecular mechanism of SAUR30 in regulating lateral root development and drought tolerance: analyzing the development of lateral roots and evaluating drought tolerance of these transgenic plants, after gene silencing of ZxSAUR30 via RNA interference (RNAi) and overexpressing of ZxSAUR30, respectively. In addition, molecular genetics methods, such as yeast two-hybrid, CoIP (co-immunoprecipitation), ChIP (chromatin immunoprecipitation) and genetic hybridization would be performed to analyze the regulatory mechanisms of SAUR30 in the processes of lateral root development and in response to drought stress by using the model plant Arabidopsis thaliana. The results could provide basis for stress-tolerant plant breeding, desert ecological protection, restoration and rational utilization.