Functional analysis of an Aspergillus ficuum phytase gene in Saccharomyces cerevisiae and its root-specific, secretory expression in transgenic soybean plants.
Phytases release inorganic phosphates from phytate in soil. A gene encoding phytase (AfPhyA) was isolated from Aspergillus ficuum and its ability to degrade phytase and release phosphate was demonstrated in Saccharomyces cerevisiae. A promoter from the Arabidopsis Pky10 gene and the carrot extensin signal peptide were used to drive the root-specific and secretory expression of the AfPhyA gene in soybean plants. The phytase activity and inorganic phosphate levels in transgenic soybean root secretions were 4.7 U/mg protein and 439 microM, respectively, compared to 0.8 U/mg protein and 120 microM, respectively, in control soybeans. Our results demonstrated the potential usefulness of the root-specific promoter for the exudation of recombinant phytases and offered a new perspective on the mobilization of phytate in soil to inorganic phosphates for plant uptake.
Li
Guilan
G
Hebei Normal University of Science & Technology, Changli, 066600, People's Republic of China.
Yang
Shaohui
S
Li
Minggang
M
Qiao
Yake
Y
Wang
Jiehua
J
D010832:6-Phytase / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics; D001230:Aspergillus / Q000201:enzymology*; D003001:Cloning, Molecular; D018552:Daucus carota / Q000235:genetics; D015870:Gene Expression; D006023:Glycoproteins / Q000235:genetics; D010710:Phosphates / Q000378:metabolism; D010833:Phytic Acid / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D021382:Protein Sorting Signals / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D013025:Glycine max / Q000235:genetics / Q000378:metabolism*
D006023:Glycoproteins; D010710:Phosphates; D010940:Plant Proteins; D021382:Protein Sorting Signals; D011993:Recombinant Fusion Proteins; C005488:extensin protein, plant; D010833:Phytic Acid; D010832:6-Phytase