Genetic background affects genetically modified ethylene sensing in birch–insect interaction

Abstract

Several studies suggest that ethylene is involved in the responses and resistance of plants against herbivores and pathogens, but the role of ethylene seems to vary depending on the system studied. Here we extend the studies of introduced Arabidopsis thaliana (L.) Heynh. ethylene receptor gene (etr1-1) to a new type of interaction: a woody plant, Betula pendula Roth (silver birch) and its herbivore, Epirrita autumnata (Borkhausen) (autumnal moth). We studied constitutive insect resistance of two wild-type birch genotypes, V and J, which were very different hosts for E. autumnata. On the J background, genetically modified ethylene insensitivity decreased the performance of E. autumnata, measured as leaf damage, larval mass, or pupal mass. However, hardly any changes were detectable in the V background, which is an inferior wild-type genotype for autumnal moth performance, except increased leaf damage caused by E. autumnata in ethylene-insensitive trees. Ethylene insensitivity caused clear side effects on birch phenology and morphology, especially in the J background. In this background, ethylene modification mainly acted via accelerating phenology, but this was hardly detectable in the V genotype. Also, the number of long shoots increased only in the modified J background. Taken together, it seems that the effects of ethylene on several birch traits relevant for E. autumnata and birch morphology depend on the birch genetic background.

Standing genetic variation and compensatory evolution in transgenic organisms: a growth-enhanced salmon simulation

“…McClelland et al 2005 ; Smoker et al 1994 ; Tymchuk et al 2006 ; Tymchuk and Devlin 2005 ). Such background genetic differences have the potential to interact with transgenes and influence phenotype, an effect that has been described in laboratory studies with other animal and plant systems (Alatalo et al 2008 ; Eisen et al 1993 ; Eisen et al 1995 ; Engler et al 1991 ; Linder 2001 ; Metz et al 2006 ; Nadeau 2001 ; Nielsen et al 1995 ; Parisi et al 2003 ; Robertson et al 2002 ; Siewerdt et al 1998 ; Siewerdt et al 2000 ; Suzuki et al 2002 ; Weng et al 1995 ). In mice, modifiers of GH transgenes have been observed and have been found to be responsive to artificial selection and to undirected natural selection (in the laboratory) that can strongly modify phenotype (Chaudhry et al 2008 ; Siewerdt et al 2000 ).…”