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

Type of publication Peer-reviewed
Publikationsform Original article (peer-reviewed)
Author Krattinger Simon G., KangJoohyun, ChauhanHarsh, Keller Beat, MartinoiaEnrico,
Project Establishing a system for the identification of Plant ABC transporter substrates and mechanisms
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Original article (peer-reviewed)

Journal New Phytologist
Title of proceedings New Phytologist
DOI 10.1111/nph.15815

Open Access

Type of Open Access Publisher (Gold Open Access)


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, as well as 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 LR34res and LR34sus act as ABA transporters. However, only the LR34res protein was detected in planta while the LR34sus version was not, suggesting a post‐transcriptional regulatory mechanism. Our results identify ABA as a substrate of the LR34 ABC transporter. We conclude that LR34res‐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.