| 19054360 |
Trusov Y, Sewelam N, Rookes JE, Kunkel M, Nowak E, Schenk PM, Botella JR: Heterotrimeric G proteins-mediated resistance to necrotrophic pathogens includes mechanisms independent of salicylic acid-, jasmonic acid/ethylene- and abscisic acid-mediated defense signaling. Plant J. 2008 Nov 28.
Summary Heterotrimeric G proteins are involved in the defense response against necrotrophic fungi in Arabidopsis. In order to elucidate the resistance mechanisms involving heterotrimeric G proteins we analyzed the effects of the Gbeta ( subunit deficiency in the mutant agb1-2 on pathogenesis-related gene expression as well as the genetic interaction between agb1-2 and a number of mutants of established defense pathways. Gbeta (-mediated signaling suppresses the induction of salicylic acid (SA)-, jasmonic acid (JA)-, ethylene- and abscisic acid (ABA)-dependent genes during the initial phase of the infection with Fusarium oxysporum (up to 48 hours after inoculation). However, at a later phase it enhances JA/ethylene-dependent genes such as PDF1.2 and PR4. Quantification of the Fusarium wilt symptoms revealed that Gbeta ( and SA deficient mutants were more susceptible than wild-type plants, while JA and ethylene insensitive and ABA deficient mutants demonstrated various levels of resistance. Analysis of the double mutants showed that Gbeta mediates resistance to F. oxysporum and Alternaria brassicicola mostly independently from all mentioned pathways. However, progressive decay of agb1-2 mutants was compensated by coi1-21 and jin1-9 mutations, suggesting that at this stage of F. oxysporum infection Gbeta acts upstream of COI1 and ATMYC2 in JA signaling. |
83(1,1,1,3) |