The Naturally Evolved EPSPS From Goosegrass Confers High Glyphosate Resistance to Rice.

Chao Ouyang,Wei Liu,Xinyan Chen,Peijin Huang,Baoguang An,Xinpeng Li,Xiuying He,Xiongxia Jin,Xiang Zeng,Yongzhong Wu,Huimin Zhao,Silan Chen

doi:10.3389/fpls.2021.756116

Chao Ouyang, Wei Liu + Show 10 more

Open Access

https://doi.org/10.3389/fpls.2021.756116

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Abstract

Glyphosate-resistant crops developed by the CP4-EPSPS gene from Agrobacterium have been planted on a massive scale globally, which benefits from the high efficiency and broad spectrum of glyphosate in weed control. Some glyphosate-resistant (GR) genes from microbes have been reported, which might raise biosafety concerns. Most of them were obtained through a hygromycin-HPT transformation system. Here we reported the plant source with 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene from goosegrass endowed rice with high resistance to glyphosate. The integrations and inheritability of the transgenes in the rice genome were investigated within two generations. The EiEPSPS transgenic plants displayed similar growth and development to wild type under no glyphosate selection pressure but better reproductive performance under lower glyphosate selection pressure. Furthermore, we reconstructed a binary vector pCEiEPSPS and established the whole stage glyphosate selection using the vector. The Glyphosate-pCEiEPSPS selection system showed a significantly higher transformation efficiency compared with the hygromycin-HPT transformation system. Our results provided a promising alternative gene resource to the development of GR plants and also extended the plant transformation toolbox.

Highlights

Glyphosate is the most widely used herbicide in global agriculture since the 1970s due to its high efficiency on non-selective and broad-spectrum inhibition of annual and perennial weeds (Duke, 2018)
There were a few glyphosate tolerance genes reported previously, most of them were introduced into plants using the hygromycin-hygromycin phosphotransferase (Hpt) or other selection systems (Tian et al, 2013; Chandrasekhar et al, 2014; Liang et al, 2017; Achary et al, 2020)
The mutated TIPSEPSPS from the goosegrass and the chloroplast target peptide from tobacco were synthesized after being codon usage optimized using OptimumGene (GenSript, Piscataway, NJ, United States), which was placed under the control of the maize Ubiquitin promoter (ZmUbipro) with an enhancer ( ) (Figure 1A)

Summary

Introduction

Glyphosate is the most widely used herbicide in global agriculture since the 1970s due to its high efficiency on non-selective and broad-spectrum inhibition of annual and perennial weeds (Duke, 2018). Glyphosate disrupts the shikimate pathway by competitively binding to the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) with phosphoenolpyruvate (PEP) (Marzabadi et al, 1996; McDowell et al, 1996) This endows glyphosate low toxicity risks to humans because the shikimate pathway is found only in microbes and plants, and not in animals (Herrmann and Weaver, 1999). One is to eliminate the toxic residues of glyphosate through acetylation, oxidative cleavage, and/or reduced translocation, such as glyphosate N-acetyltransferase (GAT) (Castle et al, 2004; Siehl et al, 2005) and glyphosate oxidoreductase (GOX) (Pedotti et al, 2009). This is called the non-target site resistance strategy.

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