Secretion of the Bacterial Phytase by Transgenic Arabidopsis Increases Phosphate Acquisition

Phytic acid (PA) is a major source of inorganic phosphate (Pi) in the soil. However, plants lack the capacity to utilize it for nutrition and growth. Microbial phytases constitute a group of enzymes that are able to remobilize Pi from PA. Thus, the use of these phytases is of agronomical interest. The research team led by Nibras Belgaroui from Centre de Biotechnologie de Sfax generated transgenic Arabidopsis lines (ePHY) overexpressing an extracellular form of the phytase PHY-US417 of Bacillus subtilis.

In the presence of PA as sole source of Pi, the wild-types showed deficiency phenotypes, including the inhibition of growth capacity. Meanwhile, the ePHY overexpressing lines show a higher biomass production and no PSI induction. Interestingly, when co-cultured with ePHY overexpressors, wild-type Arabidopsis plants show repression of the PSI genes, improvement of Pi content and increases in biomass production.

These data demonstrate the potential of secreted phytases in improving the Pi content and enhancing growth of not only the transgenic lines but also the neighbouring plants.

For more information, read the article on Plant Biotechnology Journal.