Comparative transcript profiling of resistant and susceptible peanut post-harvest seeds in response to aflatoxin production by Aspergillus flavus

Abstract

BackgroundAflatoxin contamination caused by Aspergillus flavus in peanut (Arachis hypogaea) including in pre- and post-harvest stages seriously affects industry development and human health. Even though resistance to aflatoxin production in post-harvest peanut has been identified, its molecular mechanism has been poorly understood. To understand the mechanism of peanut response to aflatoxin production by A. flavus, RNA-seq was used for global transcriptome profiling of post-harvest seed of resistant (Zhonghua 6) and susceptible (Zhonghua 12) peanut genotypes under the fungus infection and aflatoxin production stress.ResultA total of 128.72 Gb of high-quality bases were generated and assembled into 128, 725 unigenes (average length 765 bp). About 62, 352 unigenes (48.43 %) were annotated in the NCBI non-redundant protein sequences, NCBI non-redundant nucleotide sequences, Swiss-Prot, KEGG Ortholog, Protein family, Gene Ontology, or eukaryotic Ortholog Groups database and more than 93 % of the unigenes were expressed in the samples. Among obtained 30, 143 differentially expressed unigenes (DEGs), 842 potential defense-related genes, including nucleotide binding site-leucine-rich repeat proteins, polygalacturonase inhibitor proteins, leucine-rich repeat receptor-like kinases, mitogen-activated protein kinase, transcription factors, ADP-ribosylation factors, pathogenesis-related proteins and crucial factors of other defense-related pathways, might contribute to peanut response to aflatoxin production. Notably, DEGs involved in phenylpropanoid-derived compounds biosynthetic pathway were induced to higher levels in the resistant genotype than in the susceptible one. Flavonoid, stilbenoid and phenylpropanoid biosynthesis pathways were enriched only in the resistant genotype.ConclusionsThis study provided the first comprehensive analysis of transcriptome of post-harvest peanut seeds in response to aflatoxin production, and would contribute to better understanding of molecular interaction between peanut and A. flavus. The data generated in this study would be a valuable resource for genetic and genomic studies on crops resistance to aflatoxin contamination.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-016-0738-z) contains supplementary material, which is available to authorized users.

Near Infrared Spectrometry for Rapid Non-Invasive Modelling of Aspergillus-Contaminated Maturing Kernels of Maize (Zea mays L.)

“…Management is a critical strategy for aflatoxin reduction. Aflatoxin management strategies include biological control [6,7], predictive modelling [8], innovative storage techniques [9], breeding efforts [10,11], aflatoxin reduction strategies [12] and detection [13]. However, detection plays a key role in aflatoxin management because many intervention methods hinge on the ability to monitor the production of the toxin [14,15].…”

Comparative Transcriptome Analysis Reveals Molecular Defensive Mechanism of Arachis hypogaea in Response to Salt Stress

“…Transcriptomic approach is an effective tool which provides a global information towards the gene expression patterns of a plant organism under any conditions, such as drought, light, temperature, aflatoxin, and salinity stress. Numerous studies about transcriptomic characteristics of peanut have been conducted to evaluate the expression pattern of induc-ible genes under abiotic and biotic stress conditions [25,[34][35][36][37][38][39]. Transcriptome data are valuable resources for exploring plants under stress conditions.…”

The Aspergilli and Their Mycotoxins: Metabolic Interactions With Plants and the Soil Biota

“…The abscisic acid (ABA) (Hauser et al, 2011;Xin et al, 2012), salicylic acid (SA) (Janda and Ruelland, 2014), and ethylene (ET) (Bleecker and Kende, 2002;Ton et al, 2002) phytohormonal pathways in plants can act against A. flavus and AF production by mediating and channeling many stress-response genes (Bari and Jones, 2009). Transcriptomic analysis revealed DEGs of phytohormone production and signaling in response to AF production in peanut (Wang et al, 2016a). Moreover, DEGs concerning ABA production and signaling showed higher expression in a sensitive peanut genotype than in the resistant plants (Wang et al, 2016b).…”

“…Peanut was found to have evolved complex defense mechanisms to resist pathogens, such as blocking the invasion and activating a range of defense responses (Holbrook and Stalker, 2003). Eight hundred forty-two candidate genes were recognized for A. flavus resistance in post-harvest seeds (Wang et al, 2016a). Genes involved in defensive responses to A. flavus and AF biosynthesis were stimulated in resistant genotype (Wang et al, 2016b).…”

“…While opportunistic fungi usually infect plants through wounds (e.g., mechanical or pest damages), pathogenic ones actively penetrate cell walls, often through the secretion of a range of polysaccharide-degrading enzymes such as pectinesterase, arabinofuranosidase, mannosidase, and galacturonidase along with amylases or proteases (Whitehead et al, 1995;Bellincampi et al, 2014;Wang et al, 2016b). In peanuts resistant to A. flavus infection, feruloyl esterase, pectinesterase, arabinofuranosidase, mannosidase, polygalacturonase, and galacturonidase fungal activities were significantly downregulated compared to the sensitive plants (Wang et al, 2016a). Resistance to A. flavus infection is naturally the most critical factor in avoiding AF exposure to consumers.…”