The wheat Lr34 multipathogen resistance gene confers resistance to anthracnose and rust in sorghum

Abstract

SummaryThe ability of the wheat Lr34 multipathogen resistance gene (Lr34res) to function across a wide taxonomic boundary was investigated in transgenic Sorghum bicolor. Increased resistance to sorghum rust and anthracnose disease symptoms following infection with the biotrophic pathogen Puccinia purpurea and the hemibiotroph Colletotrichum sublineolum, respectively, occurred in transgenic plants expressing the Lr34res ABC transporter. Transgenic sorghum lines that highly expressed the wheat Lr34res gene exhibited immunity to sorghum rust compared to the low‐expressing single copy Lr34res genotype that conferred partial resistance. Pathogen‐induced pigmentation mediated by flavonoid phytoalexins was evident on transgenic sorghum leaves following P. purpurea infection within 24–72 h, which paralleled Lr34res gene expression. Elevated expression of flavone synthase II, flavanone 4‐reductase and dihydroflavonol reductase genes which control the biosynthesis of flavonoid phytoalexins characterized the highly expressing Lr34res transgenic lines 24‐h post‐inoculation with P. purpurea. Metabolite analysis of mesocotyls infected with C. sublineolum showed increased levels of 3‐deoxyanthocyanidin metabolites were associated with Lr34res expression, concomitant with reduced symptoms of anthracnose.

STAYGREEN, STAY HEALTHY: a loss‐of‐susceptibility mutation in the STAYGREEN gene provides durable, broad‐spectrum disease resistances for over 50 years of US cucumber production

“…New Phytologist infection are conserved in these crops (e.g. Risk et al, 2013;Rinaldo et al, 2017;Schnippenkoetter et al, 2017;Sucher et al, 2017;Boni et al, 2018).…”

Abscisic acid is a substrate of the ABC transporter encoded by the durable wheat disease resistance gene Lr34

“…All resistant wheat cultivars carry the same Lr34 allele ( Lr34res ) that evolved from an ancestral, susceptible allele ( Lr34sus ) after wheat domestication by two gain‐of‐function mutations (Krattinger et al ., ). Lr34res is functionally transferrable into all major cereals as a transgene, including barley ( Hordeum vulgare ), rice ( Oryza sativa ), maize ( Zea mays ), and sorghum ( Sorghum bicolor ) (Risk et al ., ; Krattinger et al ., ; Sucher et al ., ; Schnippenkoetter et al ., ; Boni et al ., ). In these cereal species, Lr34res resulted in enhanced resistance against various biotrophic or hemi‐biotrophic fungal pathogens, as well as in the development of LTN.…”

The wheatSr22,Sr33,Sr35andSr45genes confer resistance against stem rust in barley

“…Interestingly an APR gene has also been transferred between monocot species by transgenesis and shown to function. The wheat Lr34 adult plant resistance gene (APR), which encodes an ABC transporter, has been shown to provide resistance against multiple, diverse rust, mildew and blast fungal pathogens in barley, rice, durum wheat, maize and sorghum (Risk et al, 2013;Krattinger et al, 2016;Rinaldo et al, 2017;Sucher et al, 2017;Schnippenkoetter et al, 2017), although the mechanism of this resistance is as yet unknown. Wide interspecies transfer of functional disease resistance is therefore not limited to NLR genes.…”