干旱胁迫下苹果MsPHT1;12磷高效吸收的功能研究

Drought affects plant growth and development, also reduces the content of available phosphorus in soil, affect the P absorption of plant, utilization and translocation, causes the deficiency of physiological phosphorus in plant. In northwest of China, phosphorus deficiency and drought have become important factors that restricting the development of apple industry. Our preliminary study found that MsPHT1;12 encoding P transporter was highly expressed under drought with low phosphorus stress, indicating that MsPHT1;12 gene may be involved in drought and low phosphorus stress response. This project intends to create MsPHT1;12 overexpression and interference expression transgenic apples, and then to clarify the biological function of MsPHT1;12 by comparing with non-transgenic apples. The promoter activity of MsPHT1;12 gene was determined by yeast one-hybrid and ChIP-PCR. Our objective is to define the phosphorus transport function of MsPHT1;12 gene under drought stress, and clarify its upstream regulation mechanism. Selecting and cultivating apple rootstock with strone resistance to low phosphorus and drought stress is a good way to improve apple phosphorus ues efficiency under drought stress, which will reduce phosphorus apply in orchard, and promote the sustainable development of apple industry in northwest of China.

干旱影响植物生长发育，同时也降低了土壤中有效磷含量，抑制根系对磷的吸收和利用，引起植物生理性缺磷。西北地区磷素缺乏和干旱已经成为限制该地区苹果产业发展的重要因素。前期研究发现新疆野苹果MsPHT1;12磷转运蛋白基因在干旱低磷条件下高度表达，表明其可能参与干旱低磷双重胁迫响应。本项目拟通过创制MsPHT1;12过表达和干扰表达转基因苹果，结合非转基因苹果比较它们的抗性生理，明确MsPHT1;12在干旱低磷条件的生物学功能；同时研究MsPHT1;12基因的启动子活性，并通过酵母单杂交、ChIP-PCR技术等确定其上游的调控因子；通过以上研究，明确MsPHT1;12基因在干旱胁迫下的磷转运功能，并阐明其上游调控机理，对合理选择和定向改良培育耐低磷干旱胁迫的苹果砧木，提高干旱胁迫下苹果磷吸收利用效率，减少果园磷肥施用量，促进西北地区苹果产业的可持续发展提供理论依据。

干旱影响植物生长发育，同时也降低了土壤中有效磷含量，抑制根系对磷的吸收和利用，引起植物生理性缺磷。西北地区磷素缺乏和干旱已经成为限制该地区苹果产业发展的重要因素。因此，提高苹果在干旱下磷素的吸收利用效率具有重要意义。苹果MsPHT1;12磷转运蛋白定位于细胞膜，能够互补PHO84酵母突变体的磷转运功能，且在干旱低磷条件下高度表达。通过创制MsPHT1;12过表达转基因苹果愈伤和转基因番茄，研究发现过表达MsPHT1;12转基因苹果愈伤组织的低磷耐受性增强，过表达MsPHT1;12基因提高转基因番茄的干旱低磷抗性；同时研究MsPHT1;12基因的启动子活性，并通过酵母单杂交技术、瞬时表达技术等确定其上游的调控因子WRKY1。通过以上研究，明确了MsPHT1;12基因在干旱胁迫下的磷转运功能，并阐明其上游调控机理，对合理选择和定向改良培育耐低磷干旱胁迫的苹果砧木，提高干旱胁迫下苹果磷吸收利用效率提供理论依据。