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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #344094
Title: Aspergillus flavus infection triggered immune responses and host-pathogen cross-talks in groundnut during in-vitro seed colonization

Author
item NAYAK, SPURTHI - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India
item AGARWAL, GAURAV - University Of Georgia
item PANDEY, MANISH - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India
item SUDINI, HARI - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India
item JAYALE, ASHWIN - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India
item PUROHIT, SHILP - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India
item DESAI, AARTHI - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India
item WAN, LIYUN - Oil Crops Research Institute - China
item Guo, Baozhu
item LIAO, BOSHOU - Oil Crops Research Institute - China
item VARSHNEY, RAJEEV - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India

Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/16/2017
Publication Date: 8/29/2017
Citation: Nayak, S.N., Agarwal, G., Pandey, M.K., Sudini, H.K., Jayale, A.S., Purohit, S., Desai, A., Wan, L., Guo, B., Liao, B., Varshney, R.K. 2017. Aspergillus flavus infection triggered immune responses and host-pathogen cross-talks in groundnut during in-vitro seed colonization. Scientific Reports. 7:9659.DOI:10.1038/s41598-017-09260-8.

Interpretive Summary: Aflatoxins are a group of carcinogenic mycotoxins produced mainly by Aspergillus flavus and A. parasiticus. They are considered to be a threat to human health, global food safety, and security. Peanuts can to be colonized and contaminated by Aspergillus spp. at pre-harvest, during harvest, post-harvest drying, in storage and also during transport covering the whole value chain. Use of cultivars resistant to seed invasion by Aspergillus spp. is one of the possible means of reducing aflatoxin contamination during peanut storage with no extra input cost for the farmers. Development of aflatoxin resistant peanut varieties has been a challenging task for breeders due to lack of availability of reliable resistance sources, poor understanding of plant-fungus interactions and a large environmental influence. This study aims to better understand mechanisms of peanut resistance to Aspergillus infection by identifying genes expressed during the host-pathogen interaction. We identified 4,445 differentially-expressed peanut genes that include defense-related genes and about 578 genes that were differentially expressed by Aspergillius during interaction with peanut. These results can be used in breeding resistant varieties of peanut that will reduce aflatoxin contamination throughout the peanut production system.

Technical Abstract: Aflatoxin contamination, caused by fungal pathogen Aspergillus flavus, is a major quality and health problem delimiting the trade and consumption of groundnut (Arachis hypogaea L.) worldwide. RNA-seq approach was deployed to understand the host-pathogen interaction by identifying differentially expressed genes (DEGs) for resistance to in-vitro seed colonization (IVSC) at four critical stages after inoculation in J 11 (resistant) and JL 24 (susceptible) genotypes of groundnut. About 1344.04 million sequencing reads have been generated from sixteen libraries representing four stages in control and infected conditions. About 64% and 67% of quality filtered reads (1148.09 million) were mapped onto A (A. duranensis) and B (A. ipa'nsis) subgenomes of groundnut respectively. About 101 million unaligned reads each from J 11 and JL 24 were used to map onto A. flavus genome. As a result, 4,445 DEGs including defense-related genes like senescence-associated proteins, resveratrol synthase, 9s-lipoxygenase, pathogenesis-related proteins were identified. In A. flavus, about 578 DEGs coding for growth and development of fungus, aflatoxin biosynthesis, binding, transport, and signaling were identified in compatible interaction. Besides identifying candidate genes for IVSC resistance in groundnut, the study identified the genes involved in host-pathogen cross-talks and markers that can be used in breeding resistant varieties.