Mechanism of aflatoxin uptake in roots of intact groundnut (Arachis hypogaea L.) seedlings

Abstract

Aflatoxins are one of the most potent toxic substances that occur naturally, which enter agricultural soils through the growth of aflatoxigenic fungi in rhizhosphere and nonrhizhosphere soils. Though several reports regarding the uptake of aflatoxin by plants are available, the mechanism of aflatoxin uptake remains unknown. This study characterized the aflatoxin uptake mechanism by in vitro hydroponic experiments under variable conditions. The uptake reached saturation after 48 h of incubation for AFB1 and B2 and 60 h for AFG1 and G2. A linear increase in uptake with increasing aflatoxin concentrations was observed, and it fits both linear and nonlinear regression. AFB1 uptake was directly proportional to transpiration rate, and blocking aquaporin activity using mercuric chloride revealed its involvement in the uptake. None of the metabolic inhibitors used to block active transport had any effect on aflatoxin uptake except for sodium azide. From the present study, it could be concluded that aflatoxin uptake by groundnut roots followed mainly a passive way and is facilitated through aquaporins. The involvement of active component should be studied in detail.

Detection of Toxigenic and Atoxigenic Strains of Aspergillus flavus in Telangana and Andhra Pradesh

“…However, before exploring the antagonistic potential of these atoxigenic A. flavus strains, their atoxigenicity need to be reconfirmed using polyphasic studies. Further, there are metabolites produced by A. flavus other than aflatoxins that are toxic in nature 17,24 . Screening of these atoxigenic strains in the present study for production of these other toxic metabolites is a pre-requisite before exploring their antagonistic activities on toxigenic A. flavus at fields.…”

“…The important biotic stress in groundnut cultivation is aflatoxin contamination which occurs at both pre-and post-harvest stages of the crop. These aflatoxins are a group of twenty secondary metabolites produced by Aspergillus flavus 16 and Aspergillus parasiticus (Speare) 17,24 . In several of the documented cases, there was no direct correlation between the quantum of A. flavus infection and kernel aflatoxin contamination 5 .…”

Prevalence of Aspergillus flavus Infection and Aflatoxin Contamination of Groundnut in Telangana and Andhra Pradesh

“…It is a qualitative problem affecting grain quality and trade 23 . Aflatoxins are a group of 20 secondary metabolites produced by Aspergillus flavus Link ex Fries and Aspergillus parasiticus Speare 10,17 . Major aflatoxins are categorized as B 1 , B 2 , G 1 and G 2 based on their fluorescence under UV light and their relative chromatographic mobility during thin layer chromatography (TLC).…”

Prevalence and distribution of aflatoxin contamination in groundnut (Arachis hypogaea L.) in Mali, West Africa

“…Aspergillus flavus and A. parasiticus (Liu and Wu, 2010;Snigdha et al, 2013). These fungi 70 are ubiquitous, air-borne and soil-inhabitants, that are also found in crops and foods, 71…”