Windsor Brian, Roux Stanley J, Lloyd Alan
Section of Molecular, Cell, and Developmental Biology, and the Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA.
Nat Biotechnol. 2003 Apr;21(4):428-33. doi: 10.1038/nbt809. Epub 2003 Mar 17.
Herbicide resistance is an important trait often introduced into crop plants. Mechanisms of resistance can involve a mutant target protein that is unaffected by the herbicide, or metabolic detoxification or degradation of the herbicide. Recently, we showed that overexpression in Arabidopsis thaliana of either psNTP9, the garden pea apyrase gene, or AtPgp1, the A. thaliana homolog of the plant multidrug resistance (MDR) gene, enabled A. thaliana to germinate on the toxin cycloheximide and to grow better on toxic levels of the plant hormone N6-[2-isopentyl]adenine (2iP). Here we report that overexpression of either MDR or apyrase proteins resulted in increased resistance to herbicides from different chemical classes. Apyrase inhibition by small molecule inhibitors reversed this resistance. Treatment of untransformed plants with an apyrase inhibitor increased their sensitivity to the same herbicides. These results indicate that the genes may be involved in a resistance mechanism relating to decreased retention or increased active efflux of herbicide from the plant cell.
抗除草剂是经常导入作物中的一个重要性状。抗性机制可能涉及不受除草剂影响的突变靶蛋白，或除草剂的代谢解毒或降解。最近，我们发现，在拟南芥中过表达豌豆的apy酶基因psNTP9或植物多药抗性（MDR）基因的拟南芥同源基因AtPgp1，能使拟南芥在毒素环己酰亚胺上发芽，并在植物激素N6-[2-异戊基]腺嘌呤（2iP）的毒性水平上生长得更好。在此我们报告，MDR或apy酶蛋白的过表达导致对不同化学类别的除草剂抗性增加。小分子抑制剂对apy酶的抑制作用逆转了这种抗性。用apy酶抑制剂处理未转化的植物会增加它们对相同除草剂的敏感性。这些结果表明，这些基因可能参与了一种与植物细胞中除草剂保留减少或主动外排增加相关的抗性机制。
