利用胞嘧啶碱基编辑技术创制耐草甘膦水稻

Creation of Glyphosate-tolerant Rice by Cytosine Base Editing

草甘膦是目前使用最广泛的广谱灭生性除草剂,培育耐草甘膦基因编辑水稻将有助于改善稻田杂草化学防控效果、减少用药量和简化防控措施。本研究利用胞嘧啶碱基编辑技术对水稻内源草甘膦靶标蛋白基因OsEPSPS的第177位脯氨酸密码子进行碱基定向替换,通过农杆菌介导的遗传转化获得了靶碱基C定向替换为T的OsEPSPS(P177L)编辑材料,在其自交后代中分离鉴定获得了无外源转基因成分的纯合编辑水稻材料OsEPSPS(P177L)。载药平板试验和喷雾塔喷施试验结果表明OsEPSPS(P177L)纯合编辑水稻材料对草甘膦具有明显的抗性,可耐受四倍的草甘膦田间推荐剂量浓度。进一步调查发现P177L突变并不会对株高和发芽率等经济性状造成干扰。本研究获得的耐草甘膦水稻碱基编辑新种质OsEPSPS(P177L)为水稻的草甘膦抗性改良和稻田的杂草防治开辟了一条新的途径。

Glyphosate is the most widely used broad-spectrum herbicide.Breeding glyphosate-resistant rice(Oryza sativa L.)will help to improve the chemical control effect of weeds in rice fields,reduce the dosage of herbicide and simplify the control measures.In this study,cytosine base editing technology was used to conduct base directional substitution on the proline codon at position 177 of rice endogenous glyphosate target protein gene OsEPSPS.OsEPSPS(P177L)with base C replaced by T was obtained by Agrobacterium-mediated genetic transformation as editing material.A homozygous edited rice material OsEPSPS(P177L)was isolated and identified from its self-crossing progenies.The results showed that OsEPSPS(P177L)presented significant resistance to glyphosate and tolerated four times of the recommended concentration of glyphosate in the field.Further investigation discovered that P177L mutation did not interfere with plant height,germination rate and other economic traits.The new glyphosate-resistant rice base editing germplasm OsEPSPS(P177L)obtained in this study provides a new approach for improving glyphosate-resistant rice and weed control in rice fields.