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

Title 
Mechanism of aflatoxin uptake in roots of intact groundnut (Arachis hypogaea L.) seedlings 
Publication Type 
Journal Article 
Authors 
Snigdha M, Hariprasad P, Venkateswaran G 
Year of Publication 
2013 
Journal 
Environmental Science and Pollution Research 
Date Published 
05/2013 
ISSN 
1614-7499 
Keywords 
AFB1, AFB2, AFG1, AFG2, aflatoxigenic fungi, Aflatoxin, Aquaporins, Groundnut, mercuric chloride, sodium azide, transpiration rate, Uptake, Water 
DOI 
10.1007/s11356-013-1781-z 
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.

 
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