Effects of Arsenic on morphological, physiological and antioxidant response of soybean

ARMENDARIZ, AL; TALANO MA; WEVAR OLLER AL; AGOSTINI E.

Olomouc

Congreso; Plant Biotechnology: Green for Good; 2015

The southern region of South America is one of the largest producers and exporters of soybean (Glycine max) grains, as well as flour and oil. This crop is being often cultivated in soils with high Arsenic (As) levels and, due to the expansion of cultivated areas even to desert regions, it is sometimes irrigated with As-contaminated groundwater. Thus, the aim of this work was to evaluate soybean growth, photosynthetic pigment content, antioxidant enzymes (Peroxidase, Superoxide dismutase and Ascorbate peroxidase) and changes in root anatomy under AsV and AsIII treatments in order to elucidate the detoxification mechanisms involved and its contribution as tolerance mechanisms, after short time As-exposure. Germination and growth of soybean seedlings was significantly affected by AsV and AsIII from 25 µM. Cross sections of As-treated roots showed reduction in cortex area, dark deposits in cortex cells and broken cells of outmost layer, mainly in those seedlings treated with AsIII, since AsV-treated roots were less damaged. Soybean seedlings showed an efficient antioxidant response after As exposition, however some detrimental effects of this metalloid were observed on chlorophyll content and membrane lipids. The structural alterations in roots and the antioxidant responses would be associated with adaptation and detoxification mechanisms in As treated plants, in particular as an strategy to avoid the transport/translocation of As to the aboveground tissues.