TITLE:
Selenium Modulates Growth and Thiol Metabolism in Wheat (Triticum aestivum L.) during Arsenic Stress
AUTHORS:
Srijita Ghosh, Asok K. Biswas
KEYWORDS:
Arsenate, Glutathione, Phytochelatins, ROS, Selenate
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.8 No.3,
February
6,
2017
ABSTRACT: Arsenic affects plants by disrupting their growth
and metabolism while selenium, an essential micronutrient has beneficial role
in stress tolerance. Owing to the antioxidative capacity of selenium, it can
counteract detrimental effects of arsenic induced stress in plants. The
interactive influence of arsenate and selenate on the growth, arsenic and
selenium accumulation, activities of non-enzymatic and enzymatic antioxidants,
levels of ascorbate, α-tocopherol,
total glutathione and activities of glutathione regulatory enzymes along with
characterization and quantification of phytochelatins in growing wheat (Triticum
aestivum L.) seedlings
were investigated. Rate of arsenic accumulation was increased in arsenate
treated seedlings while in seedlings treated jointly with arsenate and selenate, arsenic accumulation
decreased. Arsenate stress resulted decrease in ascorbate and total
glutathione contents, activities of the glutathione metabolism enzymes while
significantly increased the levels of α-tocopherol
and phytochelatins (PC2 and PC4), along with activities of ascorbate peroxidase
and ascorbic acid oxidase in the test seedlings. The effects were more pronounced
in roots than in shoots. Joint application of arsenate along with selenate was
able to overcome the adverse effects caused by arsenic alone to variable
extents by exhibiting significant alterations of all parameters tested, imparting
better growth and thiol metabolism in the test seedlings. Our results conclude
that application of selenium fertilizer in arsenic contaminated soil might be
favourable to improve growth and defense ability in wheat against arsenic
toxicity.