Excessive phytochelatin and metallothione enhance reactive oxygen
species generation in absence of heavy metal
Abstract
Ethylene diamine tetraacetic acid (EDTA) is a chelating agent used
worldwide for the phytoextraction of heavy metals as well as household
and industrial purposes and persists in the cultivated land for a long
time. In this study, the effect of EDTA in the presence and in absence
of heavy metal (Chromium) was evaluated on non-hyper accumulating plant
rice (Oryza sativa L.) on the hydroponic solution at the cellular and
molecular level. EDTA application enhanced phytochelatin (PC) and
metallothionein (MT) synthesis, which was assured by up regulation of
phytochelatin and metallothionein gene in rice root. However, lower
quantity of EDTA (25µM) along with chromium enhanced the chromium (Cr)
uptake in root but inhibited its translocation to shoot pointing
vacuolar sequestration of excessive chromium in root. One the other
hand, in absence of chromium, H2O2 concentration is found to be
increased which significantly enhanced electrolyte leakage and lipid
peroxidation compared with control plants. The findings of this
investigation exhibited that excessive PCs and MTs owing to EDTA enhance
reactive oxygen species (ROS) generation in absence of heavy metal
(Chromium).