Frontiers in Bioengineering and Biotechnology (Nov 2021)

Improved the Activity of Phosphite Dehydrogenase and its Application in Plant Biotechnology

  • Tongtong Liu,
  • Tongtong Liu,
  • Lili Yuan,
  • Lili Yuan,
  • Suren Deng,
  • Xiangxian Zhang,
  • Hongmei Cai,
  • Guangda Ding,
  • Guangda Ding,
  • Fangsen Xu,
  • Fangsen Xu,
  • Lei Shi,
  • Lei Shi,
  • Gaobing Wu,
  • Chuang Wang,
  • Chuang Wang

DOI
https://doi.org/10.3389/fbioe.2021.764188
Journal volume & issue
Vol. 9

Abstract

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Phosphorus (P) is a nonrenewable resource, which is one of the major challenges for sustainable agriculture. Although phosphite (Phi) can be absorbed by the plant cells through the Pi transporters, it cannot be metabolized by plant and unable to use as P fertilizers for crops. However, transgenic plants that overexpressed phosphite dehydrogenase (PtxD) from bacteria can utilize phosphite as the sole P source. In this study, we aimed to improve the catalytic efficiency of PtxD from Ralstonia sp.4506 (PtxDR4506), by directed evolution. Five mutations were generated by saturation mutagenesis at the 139th site of PtxD R4506 and showed higher catalytic efficiency than native PtxDR4506. The PtxDQ showed the highest catalytic efficiency (5.83-fold as compared to PtxDR4506) contributed by the 41.1% decrease in the Km and 2.5-fold increase in the kcat values. Overexpression of PtxDQ in Arabidopsis and rice showed increased efficiency of phosphite utilization and excellent development when phosphite was used as the primary source of P. High-efficiency PtxD transgenic plant is an essential prerequisite for future agricultural production using phosphite as P fertilizers.

Keywords