Chromium Stress Induced Oxidative Burst in Vigna mungo (L.) Hepper:
Physio-molecular and Antioxidative Enzymes Regulation in Cellular
Homeostasis
Abstract
Blackgram [Vigna mungo (L.) Hepper] is an important legume crop with
good quality dietary proteins and vitamins. Low production of blackgram
in the chromium rich soil of Odisha is a serious concern against its
demand. Chromium (VI) was tested on V. mungo var. B3-8-8 at 100, 150,
200, 250 and 300 µM concentration on growth, anti-oxidative enzymes and
chromium content at 15, 30 and 45 d of treatments. Seed germination and
growth decreased with increase dose and duration. Cr uptake induced
oxidative burst with significant increase of osmolytes in cell level to
a greater amount in lower doses but failed to adjust homeostasis at
higher dose. Increase of GPX and SOD and decrease of CAT contain was
found in dose dependent manner. Increased protein content was observed
in <200 µM Cr concentration whereas, significant decrease of
protein was noted thereafter. Down regulation of proteins (29.2 kDa and
32.6 kDa) was observed at >250 µM of Cr. Total Cr uptake
was greater in root than in shoot which might be due to poor
translocation of heavy metal or detoxification. Thus, blackgram able to
maintain homeostasis at lower concentrations of Cr by activating the
cascade of enzymes following cellular detoxification mechanism.