Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: August 9, 2002
Publication Date: August 9, 2002
Citation: Liu, J., Samac, D.A., Allan, D., Vance, C.P. 2002. Functional analysis of different phosphate deficiency induced promoters in transgenic alfalfa. American Society of Plant Biologists Annual Meeting. Available: http://Z18.104.22.168/pb2002/public/P51/0889.html. Technical Abstract: Phosphate transporter and acid phosphatase genes are among the major phosphate (P) deficiency induced genes in higher plants. We have previously reported the cloning and characterization of a phosphate transporter gene LaPT1 and acid phosphatase gene LaSAP1 from white lupin Lupinus albus and demonstrated enhanced accumulation of mRNA in response to P deficiency. In this report we provide further details of the temporal and spatial pattern of LaPT1 and LaSAP1 promoter activity by introducing promoter::GUS reporter gene fusions into another legume species, alfalfa. Both LaPT1::GUS and LaSAP1::GUS reporter genes showed significant induction by P deficiency in transgenic alfalfa. In addition to the induced activity in roots, both promoters were induced in developing and mature nodules. In floral tissues, the LaPT1 promoter displayed enhanced activity in floral stalks, sepals, and stamen of P-deficient plants. Both LaPT1 and LaSAP1 promoters showed localized activity in developing seeds. The spatial expression patterns of these two reporter genes indicate that different P deficiency-induced genes are under combinatorial regulation by developmental signals and the phosphate status of the whole plant.