OsPTF1, a novel transcription factor involved in the tolerance to phosphate-starvation in rice (Oryza sativa L.)

摘要

We report here on OsPTFl, a novel transcription factor with a basic helix-loop-helix (bHLH) domain, involved in the tolerance to phosphate (P) starvation in rice (Oryza sativa L.). OsPTF1 was P-starvation induced in roots but constitutively expressed in shoots. Transgenic lines expressing promoter::GUS constructs showed that OsPTF1 is expressed in phloem cells of primary roots and in all cells of lateral roots. Transgenic rice plants overexpressing OsPTF1 showed enhanced tolerance to P starvation. In P-deficient hydroponic culture, number of tillers, root and shoot biomass, and the P content of transgenic rice lines were about 30% higher than those of the wild type plants, and in pot and field experiments, an approx. 20% increase in tiller number, panicle weight, and P content was observed. Moreover, under P-deficient conditions, transgenic rice plants showed a significantly higher instantaneous Pi uptake rate relative to their wild type. Microarray results further indicated that OsPTF1 is involved in Pi recycling, which is important for alleviating P deficiency in rice.