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

Abstract

Summary The wheat Lr34res allele, coding for an ATP ‐binding cassette transporter, confers durable resistance against multiple fungal pathogens. The Lr34sus allele, differing from Lr34res by two critical nucleotide polymorphisms, is found in susceptible wheat cultivars. Lr34res is functionally transferrable as a transgene into all major cereals, including rice, barley, maize, and sorghum. Here, we used transcriptomics, physiology, genetics, and in vitro and in vivo transport assays to study the molecular function of Lr34 . We report that Lr34res results in a constitutive induction of transcripts reminiscent of an abscisic acid ( ABA )‐regulated response in transgenic rice. Lr34‐ expressing rice was altered in biological processes that are controlled by this phytohormone, including dehydration tolerance, transpiration and seedling growth. In planta seedling and in vitro yeast accumulation assays revealed that both LR 34res and LR 34sus act as ABA transporters. However, whereas the LR 34res protein was detected in planta the LR 34sus version was not, suggesting a post‐transcriptional regulatory mechanism. Our results identify ABA as a substrate of the LR 34 ABC transporter. We conclude that LR 34res‐mediated ABA redistribution has a major effect on the transcriptional response and physiology of Lr34res ‐expressing plants and that ABA is a candidate molecule that contributes to Lr34res ‐mediated disease resistance.

Transcriptome analysis reveals underlying immune response mechanism of fungal (Penicillium oxalicum) disease in Gastrodia elata Bl. f. glauca S. Chow (Orchidaceae)

“…Furthermore, lots of DEGs were markedly enriched into plant hormone signal transduction pathway. Consistently, it has been reported that auxin [74,75], cytokinins [76,77], ethylene [75,[78][79][80], gibberellin [81], abscisic acid [75,82,83], brassinosteroids [80], salicylic acid [75,78,84], jasmonic acid [75,78,[84][85][86], strigolactones [87] can actively participate in disease response. Among them, salicylic acid signal transduction and jasmonic acid/ethylene signal transduction are considered as the most common plant hormone signal transduction pathways in response to biological or abiotic stress.…”

Mechanisms of powdery mildew resistance of wheat – a review of molecular breeding

“…Isolation of APR genes Pm38 and Pm46 identified a single gene encoding an ATP‐binding cassette (ABC) transporter (Krattinger et al , 2009) and a hexose transporter (Moore et al , 2015), respectively, at the multipathogen resistance locus, which confers dual resistance for wheat leaf rust and stripe rust in addition to powdery mildew. These two genes were hypothesized to undergo similar defence activation relating to a coordinated interaction of abscisic acid (ABA) and sugar signalling (Moore et al , 2015; Krattinger et al , 2019). Sugar signals have been postulated to act as priming molecules leading to PTI and ETI (Bolouri Moghaddam and van den Ende, 2012), regulating plant metabolism induced by the pathogen.…”

Genome-Wide Association Studies in Diverse Spring Wheat Panel for Stripe, Stem, and Leaf Rust Resistance

“…Despite the fact that incorporating APR into new cultivars can be difficult when compared to ASR, it was found that many wheat cultivars possessing APR showed durable resistance (Mcintosh, 1992;Boyd, 2005;Navabi et al, 2005;Singh et al, 2005;Ren et al, 2012b;Chen, 2013;Randhawa et al, 2018). Some APR genes when used in combinations have been known to possess durable pleiotropic resistance against multiple wheat rusts and powdery mildew, i.e., Lr34/Yr18/Sr57/Pm38 (on chromosome 7DS), Lr46/Yr29/Sr58/Pm39 (on chromosome 1BL), and Lr67/Yr46/Sr55/Pm46 (on chromosome 4DL) (Lagudah, 2011;Risk et al, 2012;Ellis et al, 2014), of which Lr34 has been studied extensively in different crops including rice, barley, maize, and sorghum (Krattinger et al, 2013(Krattinger et al, , 2019. Deployment of seedling (all-stage resistance), adult plant (non-race specific and race-specific) and slow rusting resistance is to create diversity for resistance (Bhardwaj et al, 2019b).…”