A vacuolar ATPase (V-ATPase.) B subunit gene has been cloned and characterized front a phosphorus starvation induced rice root subtractive cDNA library by suppression subtractive hybridization (SSH) method and RT-PCR ...A vacuolar ATPase (V-ATPase.) B subunit gene has been cloned and characterized front a phosphorus starvation induced rice root subtractive cDNA library by suppression subtractive hybridization (SSH) method and RT-PCR amplification. This gene encodes a polypeptide of 487 amino acid residues, containing a conservative ATP binding site and with a molecular weight of 54.06 kD and an isoelectric point of 4.99, southern analysis of the. genomic DNA indicates that V-ATPase B subunit is encoded by a single gene in rice genome. The amino acid homologies of V-ATPase B subunits among different organisms range from 76% to 97% and reveals that the evolution of V-ATPase B subunit is accompanied with the biological evolution. Expression pattern analysis indicated that the maximal expression of V-ATPase B subunit gene occurred at an early stage (6 - 12 h) after phosphorus starvation in roots, and lately stage (24 - 48 It) in leaves. Under phosphorus deficiency, the up-regulated expression of V-ATPase gene was presumed to strengthen the proton transport and provide the required energy to maintain an electrochemical gradient across the tonoplast to facilitate Phosphorus transport.展开更多
文摘A vacuolar ATPase (V-ATPase.) B subunit gene has been cloned and characterized front a phosphorus starvation induced rice root subtractive cDNA library by suppression subtractive hybridization (SSH) method and RT-PCR amplification. This gene encodes a polypeptide of 487 amino acid residues, containing a conservative ATP binding site and with a molecular weight of 54.06 kD and an isoelectric point of 4.99, southern analysis of the. genomic DNA indicates that V-ATPase B subunit is encoded by a single gene in rice genome. The amino acid homologies of V-ATPase B subunits among different organisms range from 76% to 97% and reveals that the evolution of V-ATPase B subunit is accompanied with the biological evolution. Expression pattern analysis indicated that the maximal expression of V-ATPase B subunit gene occurred at an early stage (6 - 12 h) after phosphorus starvation in roots, and lately stage (24 - 48 It) in leaves. Under phosphorus deficiency, the up-regulated expression of V-ATPase gene was presumed to strengthen the proton transport and provide the required energy to maintain an electrochemical gradient across the tonoplast to facilitate Phosphorus transport.
