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ARS Home » Southeast Area » Dawson, Georgia » National Peanut Research Laboratory » Research » Publications at this Location » Publication #334512
Title: Identification of expressed R-genes associated with leaf spot diseases in cultivated peanut

Author
item Dang, Phat
item Lamb, Marshall
item CHEN, CHARLES - Auburn University

Submitted to: Molecular Biology Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/1/2018
Publication Date: 11/30/2018
Citation: Dang, P.M., Lamb, M.C., Chen, C. 2018. Identification of expressed R-genes associated with leaf spot diseases in cultivated peanut. Molecular Biology Reports. 48:225-239. https://doi.org/10.1007/s11033-018-4464-5.
DOI: https://doi.org/10.1007/s11033-018-4464-5

Interpretive Summary: Peanut (Arachis hypogaea L.) is an important source of food and oilseed crop worldwide. Yield and quality can be significantly reduced by foliar fungal diseases, such as early and late leaf spots. Acceptable levels of leaf spot resistance in cultivated peanut has been elusive due to the combination of environmental interactions and the proper combination of resistance genes in any particular peanut genotype. Resistance Gene Analogs (RGAs), as potential resistant gene candidates, have unique roles in the recognition and activation of disease resistance response. Identification of RGAs target conserved domains such as nucleotide binding site, leucine rich repeats, receptor kinases, and receptor like proteins. Expressed RGAs represent necessary genes in a disease resistance response. The goals of this research are to identify expressed RGAs from leaves that are naturally infected by early and late leaf spots and to compare these RGAs to diploid progenitors. Putative peanut RGAs (381) were available from a public database. Molecular techniques were applied to obtain DNA sequence information about importance genes from peanut leaves infected with leaf spot fungus. Based on conserved DNA domains of RGAs, 209 potential disease resistance genes were identified and catalogued. These were compared to the peanut diploid progenitors of the cultivated peanuts. Similarities were observed which suggest conservation of disease resistance genes during peanut evolution. Identification and association of specific gene-expression will facilitate selection of peanut lines with high levels of leaf spot resistance.

Technical Abstract: Peanut (Arachis hypogaea L.) is an important source of food and oilseed crop worldwide. Yield and quality can be significantly reduced by foliar fungal diseases, such as early and late leaf spots. Acceptable levels of leaf spot resistance in cultivated peanut has been elusive due to the combination of environmental interactions and the proper combination of QTLs in any particular peanut genotype. Resistance Gene Analogs (RGAs), as potential resistant gene candidates, have unique roles in the recognition and activation of disease resistance response. Identification of RGAs target conserved domains such as nucleotide binding site, leucine rich repeats, receptor kinases, and receptor like proteins. Expressed RGAs represent necessary genes in a disease resistance response. The goals of this research are to identify expressed RGAs from leaves that are naturally infected by early and late spots and to compare these RGAs to diploid progenitors. Putative peanut RGAs (381) were available from a public database (NCBI). Primers were designed and PCR products were sequenced. A total of 209 RGAs sequences were produced which matched proteins with the corresponding RGA motifs. These RGAs were mapped to diploids, Arachis duranenis and Arachis ipaensis, which show conservation of RGA genes compared to the cultivated peanut Arachis hypogaea. Identification and association of specific gene-expression will facilitate selection of peanut lines with high levels of leaf spot resistance.