Phosphorus （P） deficiency is a major limitation for plant growth and development. Among the wide set of responses to cope with low soil P, plants increase their level of intracellular and secreted acid phosphatases ...Phosphorus （P） deficiency is a major limitation for plant growth and development. Among the wide set of responses to cope with low soil P, plants increase their level of intracellular and secreted acid phosphatases （APases）, which helps to catalyze inorganic phosphate （Pi） hydrolysis from organophosphates, in this study we characterized the rice （Oryza sativa） purple acid phosphatase 10a （OsPAPIOa）. OsPAPIOa belongs to group la of purple acid phosphatases （PAPs）, and clusters with the principal secreted PAPs in a variety of plant species including Arabidopsis. The transcript abundance of OsPAPIOa is specifically induced by Pi deficiency and is controlled by OsPHR2, the central transcription factor controlling Pi homeostasis. In gel activity assays of root and shoot protein extracts, it was revealed that OsPAPIOa is a major acid phosphatase isoform induced by Pi starvation. Constitutive overexpression of OsPAPIOa results in a significant increase of phosphatase activity in both shoot and root protein extracts. In vivo root 5-bromo.4-chloro-3-indolyl-phosphate （BCIP） assays and activity measurements on external media showed that OsPAPIOa is a root-associated APase. Furthermore, overexpression of OsPAPIOa significantly improved ATP hydrolysis and utilization compared with wild type plants. These results indicate that OsPAPIOa can potentially be used for crop breeding to improve the efficiency of P use.展开更多
基金supported by the Sina-Australia Science Cooperation Fund(2010DFA31080)the National Natural Science Foundation(31172024)+1 种基金the Ministry of Science and Technology of China(20080242 and 2011ZX08004–001-03)the Zhejiang Bureau of Science and Technology (R3090229)
文摘Phosphorus （P） deficiency is a major limitation for plant growth and development. Among the wide set of responses to cope with low soil P, plants increase their level of intracellular and secreted acid phosphatases （APases）, which helps to catalyze inorganic phosphate （Pi） hydrolysis from organophosphates, in this study we characterized the rice （Oryza sativa） purple acid phosphatase 10a （OsPAPIOa）. OsPAPIOa belongs to group la of purple acid phosphatases （PAPs）, and clusters with the principal secreted PAPs in a variety of plant species including Arabidopsis. The transcript abundance of OsPAPIOa is specifically induced by Pi deficiency and is controlled by OsPHR2, the central transcription factor controlling Pi homeostasis. In gel activity assays of root and shoot protein extracts, it was revealed that OsPAPIOa is a major acid phosphatase isoform induced by Pi starvation. Constitutive overexpression of OsPAPIOa results in a significant increase of phosphatase activity in both shoot and root protein extracts. In vivo root 5-bromo.4-chloro-3-indolyl-phosphate （BCIP） assays and activity measurements on external media showed that OsPAPIOa is a root-associated APase. Furthermore, overexpression of OsPAPIOa significantly improved ATP hydrolysis and utilization compared with wild type plants. These results indicate that OsPAPIOa can potentially be used for crop breeding to improve the efficiency of P use.
