MOLECULAR BIOLOGY AND PHYSIOLOGY Foliar Antioxidant Enzyme Responses in Cotton after Aphid Herbivory

Cotton aphid (Aphis gossypii G.) populations in the field have fluctuated over the past years, yet it is unknown whether infestation by these insects alters cotton (Gossypium hirsutum L.) physiology. Although it is important to determine if aphids con-tribute to plant stress, there is only limited informa-tion on plant stress responses after aphid herbivory. In an attempt to quantify plant stress, the activity of cotton foliar antioxidant enzymes after aphid feeding was examined. Cotton aphids were col-lected from cotton fields at Lonoke, AR, and reared in the laboratory. Fifty aphids were transferred to cotton (G. hirsutum ‘Stoneville 474’) leaves of the same age and size, and were allowed to increase i