Arsenic-induced oxidative stress in the common bean legume, Phaseolus vulgaris L. seedlings and its amelioration by exogenous nitric oxide

Abstract

The adverse effects of arsenic (As) toxicity on seedling growth, root and shoot anatomy, chlorophyll and carotenoid contents, root oxidizability (RO), antioxidant enzyme activities, H 2 O 2 content, lipid peroxidation and electrolyte leakage (EL%) in common bean (Phaseolus vulgaris L.) were investigated. The role of exogenous nitric oxide (NO) in amelioration of As-induced inhibitory effect was also evaluated using sodium nitroprusside (100 μM SNP) as NO donor and 2-(4-carboxy-2-phenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (200 μM PTIO) as NO scavenger in different combinations with 50 μM As. Asinduced growth inhibition was associated with marked anomalies in anatomical features, reduction in pigment composition, increased RO and severe perturbations in antioxidant enzyme activities. While activity of superoxide dismutase and catalase increased, levels of ascorbate peroxidase, dehydroascorbate reductase and glutathione reductase decreased significantly and guaiacol peroxidase remained normal. The over-accumulation of H 2 O 2 content along with high level of lipid peroxidation and electrolyte leakage indicates As-induced oxidative damage in P. vulgaris seedlings with more pronounced effect on the roots than the shoots. Exogenous addition of NO significantly reversed the As-induced oxidative stress, maintaining H 2 O 2 in a certain level through balanced alterations of antioxidant enzyme activities. The role of NO in the process of amelioration has ultimately been manifested by significant reduction of membrane damage and improvement of growth performance in plants grown on As + SNP media. Onset of oxidative stress was more severe after addition of PTIO, which confirms the protective role of NO against Asinduced oxidative damage in P. vulgaris seedlings.

Growth Responses and Leaf Antioxidant Metabolism of Grass Pea (Lathyrus sativus L.) Genotypes under Salinity Stress

“…Similar situation was also observed in salt-affected cereals, legumes and other vegetable crops [34,39,57,61,67]. Significant increase in MDA content and loss in photosynthetic apparatus have been recognized as the marks of oxidative stress in plants [5,6,10,39,57,64,68,69] and may be one of the prime reasons for NaCl-induced growth inhibition in the present material. It is also clear that oxidative damage at initial growth stages was effectively prevented in four genotypes by mitigating membrane damage at reproductive stage, but it was quite impossible for the PUSA-90-2 and WBK-CB-14 varieties to recover from NaCl-induced oxidative damage due to complete failure of antioxidant defense throughout the treatment period.…”

Role of soil associated Exiguobacterium in reducing arsenic toxicity and promoting plant growth in Vigna radiata

“…5f). Previous studies also reported severe lipid peroxidation in different plant species under arsenic stress [56,58]. The increase in activity of these antioxidative enzymes and MDA content is quite obvious for the efficient recycling of ROS to ensure normal plant growth.…”

Metal uptake, oxidative metabolism, and mycorrhization in pigeonpeaand pea under arsenic and cadmium stress

“…Most As and Cd appeared to be accumulated in roots and only a limited amount was translocated to the aboveground parts, suggesting their low mobility in both species. Greater capacity of a species to accumulate appreciable amounts of metal(loid)s in roots and their restricted transfer to the aerial tissue signifies its better ability to tolerate metal(loid) stress (Ishtiaq and Mahmood, 2011;Garg and Singla, 2012;Talukdar, 2013). Tiwari et al (2014) found enhanced expression of transporters (OsNRAMP1) in transgenic lines of rice, which might have contributed to considerable accumulation of Cd and As in roots.…”