Insights on host-pathogen interaction between groundnut (Arachis hypogaea) and Aspergillus flavus uri icon

abstract

  • Aflatoxin contamination, caused by fungal pathogen Aspergillusflavus, is the major quality and health problem delimiting the tradeand consumption of groundnut (Arachis hypogaea L.) worldwide.Three types of aflatoxin resistance mechanisms namely, resistanceto in-vitro seed colonization (IVSC), pre-harvest aflatoxincontamination (PAC) and aflatoxin production (AP) have beenreported in groundnut. Transcriptome sequencing approach wasused to study the differentially expressed genes that differ in-vitroseed colonization (IVSC) in resistant (J 11) and susceptible(JL 24) genotypes. A total of 1,344 million raw reads with anaverage of 84 million reads per sample were generated from 16libraries from four different stages of fungal infection. A total of737.75 and 770.83 million reads were mapped on the progenitorgenomes- A subgenome (A. duranensis) and B subgenome (A.ipaensis) of cultivated groundnut (A. hypogaea), respectively. Ingroundnut, defense related genes like senescence associatedproteins, resveratrol synthase, seed linoleate 9s-lipoxygenases(9s-LOX), pathogenesis related proteins, peroxidases, glutathione-S-transferases, chalcone synthase, defensin and chitinaseswere differentially expressed. In A. flavus, the genes involvedin growth and development of fungus, aflatoxin biosynthesis,binding and transporter proteins were found to be induced incompatible interaction. In addition to IVSC resistance, we havealso carried out transcriptome sequencing for PAC and AP resistance.In summary, this study will provide greater insights onthe resistance mechanisms and discovery of candidate genes forall the three mechanisms that can further be used as expressionmarkers in genomics-enabled aflatoxin resistance breeding

publication date

  • 2017