Molecular cloning and characterization of an inorganic phosphate transporter protein encoding gene in Polyporus umbellatus / 中草药

Objective To clone an inorganic phosphate transporter (PiT) gene from Polyporus umbellatus and perform the bioinformatics and expression mode analysis. Methods Using RT-PCR.to clone the full-length cDNA of PiT. The characteristics of physiochemical properties, conserved domains, signal peptide and transmembrane domain of the predicted PiT protein were determined by using bioinformatic tools. Results A inorganic phosphate transporter (PiT) gene (NCBI: KU179154), designated as PuPiT, was cloned from Polyporus umbellatus sclerotia by RT-PCR. The full open reading frame cDNA sequence of PuPiT was 1 590 bp, encoding a putative PiT protein with 530 amino acids with a molecular weight of 57 552, and a theoretical pI of 6.82. The amino acids possess 12 membrane-spanning domains. Phylogenetic tree analysis indicated that PuPiT had the highest similarity with PiT from Moniliophthora rorer, and had high similarity with Moniliophthora roreri, Laccaria bicolor, and Heterobasidion irregulare. Quantitative real-time PCR showed that PuPiT expressed in both the symbiotic part and non-symbiotic part. Meanwhile, the expression of PuPiT in the symbiotic part was significantly up-regulated, about 12 times more than that in the non-symbiotic part. This result showed that PuPiT might play an important role in the Pi accumulating. Conclusion Molecular cloning and characterization of the novel PuPiT gene will be useful for further functional determination of the gene involving in phosphorus translocation regulation and symbiotic process.

Response of aerobic rice to Piriformospora indica.

Rice cultivation under aerobic condition not only saves water but also opens up a splendid scope for effective application of beneficial root symbionts in rice crop unlike conventional puddled rice cultivation where water logged condition acts as constraint for easy proliferation of various beneficial soil microorganisms like arbuscular mycorrhizal (AM) fungi. Keeping these in view, an in silico investigation were carried out to explore the interaction of hydrogen phosphate with phosphate transporter protein (PTP) from P. indica. This was followed by greenhouse investigation to study the response of aerobic rice to Glomus fasciculatum, a conventional P biofertilizer and P. indica, an alternative to AM fungi. Computational studies using ClustalW tool revealed several conserved motifs between the phosphate transporters from Piriformospora indica and 8 other Glomus species. The 3D model of PTP from P.indica resembling “Mayan temple” was successfully docked onto hydrogen phosphate, indicating the affinity of this protein for inorganic phosphorus. Greenhouse studies revealed inoculation of aerobic rice either with P. indica, G. fasciculatum or both significantly enhanced the plant growth, biomass and yield with higher NPK, chlorophyll and sugar compared to uninoculated ones, P. indica inoculated plants being superior. A significantly enhanced activity of acid phosphatase and alkaline phosphatase were noticed in the rhizosphere soil of rice plants inoculated either with P. indica, G. fasciculatum or both, contributing to higher P uptake. Further, inoculation of aerobic rice plants with P. indica proved to be a better choice as a potential biofertilizer over mycorrhiza.

Advances of Study on Arbuscular Mycorrhizal Symbiotic Phosphate Transporter in Plants / 中国生物工程杂志

The arbuscular mycorrhizal(AM)symbiosis is a mutualistic endosymbiosis formed by plant roots and AM fungi.The AM symbiosis is manifested in bidirectional nutrient exchange: AM fungi obtain carbon from their plant host while assisting the plant with the acquisition of mineral nutritions(in particular phosphate)from the soil.AM symbiosis facilitate phosphate uptake is the central reason of plant growth and development.Phosphate transport into the root is mediated by phosphate transporters,and phosphate transporters play a role in the acquisition of phosphate released by the fungus in the AM symbiosis.The molecular biology of arbuscular mycorrhizal symbiotic phosphate transporters in plants was summarized.AM phosphate transporter belong to Pht1 family,is not only essential for the acquisition of phosphate,also critical to AM symbiosis.Study of phosphate transport roles and their gene regulation will further our knowledge of the interaction between the two symbiotic partners,and so as to provide innovative approach to improving phosphate efficiency and agricultural yield.