Global transcriptome profiling identified transcription factors, biological process, and associated pathways for pre-harvest aflatoxin contamination in peanut

Authors: SONI, POOJA - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India; PANDEY, ARUN - China Jiliang University; NAYAK, SPURTHI - University Of Agricultural Sciences; PANDEY, MANISH - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India; TOLANI, PRIYA - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India; PANDEY, SARITA - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India; SUDINI, HARI - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India; BAJAJ, PRASAD - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India; FOUNTAIN, JAKE - Mississippi State University; SINGAM, PRASHANT - Osmania University; Guo, Baozhu; VARSHNEY, RAJEEV - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India

Submitted to: The Journal of Fungi
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/23/2021
Publication Date: 5/26/2021
Citation: Soni, P., Pandey, A.K., Nayak, S.N., Pandey, M.K., Tolani, P., Pandey, S., Sudini, H.K., Bajaj, P., Fountain, J.C., Singam, P., Guo, B., Varshney, R.K. 2021. Global transcriptome profiling identified transcription factors, biological process, and associated pathways for pre-harvest aflatoxin contamination in peanut. The Journal of Fungi. 7:1-18. https://doi.org/10.3390/jof7060413.
DOI: https://doi.org/10.3390/jof7060413

Interpretive Summary: Pre-harvest aflatoxin contamination (PAC) in peanut is a serious quality concern globally and drought stress in the field before harvest exacerbates its intensity leading to quality deterioration of peanuts. Understanding the host-pathogen interaction and identification of candidate genes responsible for resistance to PAC will provide insights into the defense mechanisms in peanuts. This study used the next-generation sequencing (NGS) based transcriptomic approach and examined the resistance mechanism by identifying novel genes and pathways. There were total of 971.63 million reads generated from 16 RNA samples of control and Aspergillus flavus infection from one susceptible genotype and seven resistant genotypes. The RNA-seq analysis identified 45,336 genome-wide transcripts in both control and infected conditions. This study indicated a vital role of ABA-responsive ABR17 in providing resistance against A. flavus infection, which belongs to PR-10 class and induced in several plant-pathogen interactions. The putative candidate genes, which were differentially expressed in these cultivars, could be targetted for further validation and developing trait-associated markers for breeding aflatoxin resistant peanut.

Technical Abstract: Pre-harvest aflatoxin contamination (PAC) in peanut is a serious quality concern globally and drought stress in the field before harvest further exacerbates its intensity leading to quality deterioration of the produce. Understanding the host-pathogen interaction and identification of candidate genes responsible for resistance to PAC will provide insights into the defense mechanisms in the groundnut/peanut. In this context, about 971.63 million reads have been generated from 16 RNA samples under control and A. flavus infected condition from one susceptible and seven resistant genotypes. The RNA-seq analysis identified 45,336 genome-wide transcripts during control and infected conditions. This study identified 57 transcription factor (TF) families with major contribution from 6570 genes coding for bHLH (719), MYB-related (479), NAC (437), FAR1 family protein (320), and several other families. In host (groundnut) defense-related genes like senescence-associated proteins, resveratrol synthase, seed linoleate, pathogenesis-related proteins, peroxidases, glutathione-S-transferases, chalcone synthase, ABA-responsive genes, and chitinases were found differentially expressed among resistant genotypes as compared to the susceptible one. This study also indicated a vital role of ABA-responsive ABR17, co-regulates genes of ABA responsive elements during drought stress, in providing resistance against A. flavus infection, which belongs to PR-10 class and also induced in several plant-pathogen interactions.