Department of Plant Sciences, UC Davis
Regulation and function of Pht1 family phosphate transporters in rice
- Author(s): Ai, Penghui
- Sun, Shubin
- Zhao, Jianning
- Xu, Guohua
- et al.
In the genome of rice (Oryza sativa) 13 sequences are predicted to be members of high affinity phosphate (Pi) transporters (Pht1) family. We constructed chimeric promoter constructs of the rice Pht1 genes with β-glucuronidase (GUS) and introduced them into rice by Agrobacterium-mediated transformation. The temporal and spatial expression and activity of GUS were assayed in rice grown in nutrient solutions with Pi-deficiency and Pi-sufficiency. Eight promoters of these genes; OsPT1, OsPT2, OsPT3, OsPT4, OsPT5, OsPT6, OsPT7 and OsPT8, drove GUS expression with varying levels in the Pi-deprived roots. These expression patterns were further confirmed by RT-PCR analyses. There was increased expression of OsPT1, OsPT6 and OsPT8 in epidermal cells of Pi-starved young primary and lateral roots. Differences were also noticed in expression of OsPT1, OsPT2, OsPT3, OsPT4, OsPT6, OsPT7 and OsPT8 in stamens, caryopses or germinated seeds. The results suggest that Pi-acquisition by roots and its translocation inside the plant requires coordinated expression of multiple Pi-transporters under Pi-deficiency condition.