The wheat durable, multipathogen resistance gene Lr34 confers partial blast resistance in rice
Year:2016
Bibliography
Krattinger SG, Sucher J, Selter LL, Chauhan H, Zhou B, Tang, M, Upadhyaya NM, Mieulet D, Guiderdoni E, Weidenbach D, Schaffrath U, Lagudah ES and Keller B (2016) The wheat durable, multi-pathogen resistance gene Lr34 confers partial blast resistance in rice. Plant Biotechnology Journal14: 1261-1268.
Abstract
The wheat gene Lr34 confers durable and partial field resistance
against the obligate biotrophic, pathogenic rust fungi and powdery
mildew in adult wheat plants. The resistant Lr34 allele evolved
after wheat domestication through two gain‐of‐function mutations in an
ATP‐binding cassette transporter gene. An Lr34‐like fungal
disease resistance with a similar broad‐spectrum specificity and
durability has not been described in other cereals. Here, we transformed
the resistant Lr34 allele into the japonica rice cultivar Nipponbare. Transgenic rice plants expressing Lr34 showed increased resistance against multiple isolates of the hemibiotrophic pathogen Magnaporthe oryzae, the causal agent of rice blast disease. Host cell invasion during the biotrophic growth phase of rice blast was delayed in Lr34‐expressing rice plants, resulting in smaller necrotic lesions on leaves. Lines with Lr34
also developed a typical, senescence‐based leaf tip necrosis (LTN)
phenotype. Development of LTN during early seedling growth had a
negative impact on formation of axillary shoots and spikelets in some
transgenic lines. One transgenic line developed LTN only at adult plant
stage which was correlated with lower Lr34 expression levels at
seedling stage. This line showed normal tiller formation and more
importantly, disease resistance in this particular line was not
compromised. Interestingly, Lr34 in rice is effective against a
hemibiotrophic pathogen with a lifestyle and infection strategy that is
different from obligate biotrophic rusts and mildew fungi. Lr34
might therefore be used as a source in rice breeding to improve
broad‐spectrum disease resistance against the most devastating fungal
disease of rice.