首页 | 本学科首页   官方微博 | 高级检索  
   检索      


Effect of herbicide diclofop-methyl on proton extrusion from Lolium multiflorum seedlings differing in resistance and in fungal endophyte (Neotyphodium sp.) infection
Authors:Martin M Vila-Aiub  Claudio M Ghersa  Marta Carceller
Institution:IFEVA,Departamento de Recursos Naturales y Ambiente and; Departamento de Biologia Aplicada y Alimentos, Facultad de Argonomia, Universidad de Buenos Aires (UBA), Avenue San Martín 4453 (C1417DSE), Buenos Aires, Argentina
Abstract:Lolium multiflorum (Italian ryegrass), an annual weed invading wheat and barley cropping systems, has evolved resistance to diclofop-methyl (DM) herbicide. Earlier studies on the mode of action of DM in susceptible L. multiflorum and L. rigidum populations have shown that herbicide promotes oxidative stress leading to senescence, a process reversible through the action of auxins. The disruption of cell membrane potential ( E m ) appears to be correlated with DM phytotoxicity in susceptible populations, suggesting that the continuous H+ extrusion from plasmalemma to extracellular space is inhibited. L. multiflorum usually establishes a symbiotic relationship with fungal endophytes of the Neotyphodium genus. This fungus confers to host plants higher survival at sublethal dosages of DM, probably due to the production of auxinic compounds. Our goal was to characterize DM-resistant and DM-susceptible L. multiflorum populations infected (E+) and non-infected (E?) with endophytes, by studying the capacity of H+ bumping of plasmalemma of intact roots under DM selection. We correlated the effects of DM on H+ disruption with plant survival. DM inhibited acidification markedly more in susceptible than in resistant populations. Continued extrusion of H+ by DM-resistant cell membranes was positively related to plant survival and growth. There was no detectable difference in the capacity of bumping H+ between DM-susceptible E+ and E? seedlings, even though survival was higher in E+ plants. The basis for the differential response in H+ extrusion between resistant and susceptible populations of L. multiflorum is discussed.
Keywords:
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号