Abstract
Arsenic (As) traces have been reported worldwide in vegetables and crops cultivated in As-polluted soils. Being carcinogenic, the presence of As in edibles is of great concern as it ultimately reaches humans and animals through the food chain. Besides, As toxicity adversely affects the growth, physiology, metabolism, and productivity of crops. In the present study, Trigonella foenum-graecum (Fenugreek) was exposed to the As stress (0, 50, 100, and 150 mu M sodium arsenate) for a week. Further, evaluation of As accumulation in roots and shoots, magnitude and visualization of oxyradicals, and thiol-based defence offered by Fenugreek was assessed. The root and leaf accumulated 258-453 mu g g(-1) dry wt (DW) and 81.4-102.1 mu g g(-1) DW of As, respectively. An arsenic-mediated decline in the growth index and increase in oxidative stress was noted. Arsenic stress modulated the content of thiol compounds; especially cysteine content increased from 0.36 to 0.43 mu mole g(-1) FW protein was noted. Random Amplified Polymorphic DNA (RAPD)-based analysis showed DNA damage in As-treated plants. Health risk assessment parameters showed that As concentration in the consumable plant shoot was below the critical hazard level (hazard quotient < 1). Moreover, T. foenum-graecum showed varied responses to As-induced oxidative stress with applied concentrations (150 mu M being more toxic than lower concentrations). In addition, the RAPD profile and level of thiol compounds were proved significant biomarkers to assess the As toxicity in plants. The conclusion of this study will help users of fenugreek to have a clue and create awareness regarding the consumption.