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ARS Home » Pacific West Area » Wenatchee, Washington » Physiology and Pathology of Tree Fruits Research » Research » Publications at this Location » Publication #327076

Title: Identification and functional analysis of apple CERK1 homologous genes for their roles in defense activation

item Zhu, Yanmin
item ZHOU, ZHE - Chinese Academy Of Agricultural Sciences
item CONG, PEIHUA - Chinese Academy Of Agricultural Sciences
item YI, TIAN - Chinese Academy Of Agricultural Sciences

Submitted to: APS Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/5/2016
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Plants use their pattern-recognition receptor (PRR) to detect the presence of a specific pathogen and subsequently activate the corresponding defense responses. The roles of PRR are directly associated with disease resistance in both model and crop plants. Lysin motif (LysM) receptor kinase, such as AtCERK1 from Arabidopsis, is among the well-characterized PRR which can bind chitins and other pathogen-associated molecular patterns (PAMPs). In the apple (Malus x domestics) genome, two AtCERK1 homologous genes, MdCERK1-1 and MdCERK1-2, were identified; and their predicted amino acid sequences show 60% of identity with AtCERK1. Both MdCERK1s contain a conserved LysM, a transmembrane (TM) and a kinase domain. Previous transcriptome analysis indicated that MdCERK1-1 was activated in response to infection by Pythium ultimum. The ability of MdCERK1 to bind chitin was demonstrated, and its interacting partners in apple cells were identified by proteomics analysis using an MdCERK1-GST fusion protein in a pull-down assay. Differential expression patterns for both MdCERK1 genes were observed as apple plants are challenged with P. ultimum, Rhizoctonia solani AG-5 and Alternaria alternata. Genotype-specific expression patterns of defense related genes functioning downstream of MdCERK1, for example the biosynthesis of defense metabolites and plant hormone signaling, seem to be associated with the observed resistance levels to these pathogens. The genetic complementation of Arabidopsis cerk1 mutants by transgenic expression of MdCERK1 genes and the over-expression in apple plants is under way to infer more definitive roles for both MdCERK1 genes during defense against various foliar and root pathogens.