Down-regulation of Arabidopsis DND1 orthologs in potato and tomato leads to broad-spectrum resistance to late blight and powdery mildew

Abstract

Multiple susceptibility genes (S), identified in Arabidopsis, have been shown to be functionally conserved in crop plants. Mutations in these S genes result in resistance to different pathogens, opening a new way to achieve plant disease resistance. The aim of this study was to investigate the role of Defense No Death1 (DND1) in susceptibility of tomato and potato to late blight (Phytophthora infestans). In Arabidopsis, the dnd1 mutant has broad-spectrum resistance against several fungal, bacterial, and viral pathogens. However this mutation is also associated with a dwarfed phenotype. Using an RNAi approach, we silenced AtDND1 orthologs in potato and tomato. Our results showed that silencing of the DND1 ortholog in both crops resulted in resistance to the pathogenic oomycete P. infestans and to two powdery mildew species, Oidium neolycopersici and Golovinomyces orontii. The resistance to P. infestans in potato was effective to four different isolates although the level of resistance (complete or partial) was dependent on the aggressiveness of the isolate. In tomato, DND1-silenced plants showed a severe dwarf phenotype and autonecrosis, whereas DND1-silenced potato plants were not dwarfed and showed a less pronounced autonecrosis. Our results indicate that S gene function of DND1 is conserved in tomato and potato. We discuss the possibilities of using RNAi silencing or loss-of-function mutations of DND1 orthologs, as well as additional S gene orthologs from Arabidopsis, to breed for resistance to pathogens in crop plants.Electronic supplementary materialThe online version of this article (doi:10.1007/s11248-015-9921-5) contains supplementary material, which is available to authorized users.

Plant behaviour under combined stress: tomato responses to combined salinity and pathogen stress

“…AtCNGC2 in Clough et al, 2000). Silencing tomato and potato orthologs of AtCNGC2 resulted in resistance to Phytophthora infestans (Sun et al, 2016). Further, NHX1 Na + -H + antiporter activity was shown to be involved in regulation of vacuolar pH and cellular oxidation for the optimal induction of plant defense (Chen et al, 2014).…”

Why Organic Farming Should Embrace Co-Existence with Cisgenic Late Blight–Resistant Potato

“…Both the ODM and SDN technologies can, for instance, be used to edit particular potato genes-which are called S-genes (susceptibility genes)-in such a way that the pathogen can no longer multiply [45]. The biotechnology company Cibus based in San Diego, California, is working on LBR in potato using ODM, and in other places in the world the SDN technology is being explored for the same purpose.…”

Susceptibility genes : an additional source for improved resistance

“…StDND1-silenced plants showed resistance to the four tested isolates, Pic99189, Pic99177, USA618 and EC#1 (Sun et al 2016a). StDMR1-and StDMR6-silenced plants were found to be resistant to Pic99189, which was the only isolate tested (Sun et al 2016b).…”

“…A time lapse video was produced to visualize development of P. infestans infection on leaves of cv Desiree and on StDND1-, StDMR1-or StDMR6-silenced potato transformants. The time lapse protocol described in Sun et al (2016a) was applied. Leaflets were taken from the same plants as those used in the DLA (see above).…”

“…In Arabidopsis, more than 150 S genes have been described (van Schie & Takken 2014). There is more and more evidence that orthologs of the Arabidopsis S genes are present in crop species (Bai et al 2008;Sun et al 2016a). In potato it was shown that reduced expression via RNAi of the putative S gene SYNTAXIN-RELATED1 (StSYR1), an ortholog of AtSYP121/AtPEN1 of Arabidopsis, decreased the susceptibility to P. infestans (Eschen-Lippold et al 2012a & b).…”