Antioxidant Enzyme Responses of Winter Wheat to Drought Stress
Varga, B., Janda, T., Laszlo, E. and Veisz, O. 2012. Influence of abiotic stresses on the antioxidant enzyme activity of cereals. Acta Physiologiae Plantarum 34: 849-858.
In an experiment designed to further explore this subject, Varga et al. grew two varieties of winter wheat within phytotrons maintained at either 380 or 750 ppm CO2, where the potted plants were watered daily and supplied with nutrient solution twice a week until the start of drought treatments, when drought was induced in three phases - at first node appearance, heading and grain filling - by completely withholding water for seven days, which dropped the volumetric soil water content in the pots from 20-25% to 3-5%.
In describing their results, the four researchers - all of whom are associated with the Agricultural Research Institute of the Hungarian Academy of Sciences - report that they observed "changes in enzyme activity" that "indicated that enhanced CO2 concentration delayed the development of drought stress up to first node appearance, and stimulated antioxidant enzyme activity when drought occurred during ripening, thus reducing the unfavorable effects of [drought] stress." Varga et al. also state that the increases in the antioxidant enzymes they analyzed "may help to neutralize the reactive oxygen species induced by stress during various parts of the vegetation period." And this phenomenon may help mankind's crops to better cope with whatever extremes of moisture insufficiency might be lurking in our future.
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