The sunflower has a fundamental role in the global economy, being one of the most important crops for oil production. The plants have a short growing season and it adapts well to different soil conditions and unfavorable weather. The present study aimed to evaluate the impact of drought on leaf water potential, the content of photosynthetic pigments and antioxidant responses in two cultivars of sunflower. Seeds of the M735 cv. and MG2 cv. were sown in pots and four plants were maintained per pot that was arranged randomly. Plants were grown in a greenhouse, and two months after sowing, subjected to water stress: Irrigated and not irrigated. Evaluations were performed after 1, 5 and 12 days of induction the stress treatment. Significant reduction in leaf water potential at 5 and 12 days in M735 cv. and 12 days for MG2 cv., were observed. The pigment content did not differ between treatments. There was no change in antioxidant enzyme activity for the M735 cv., though the levels of H 2 O 2 increased in non-irrigated plants after 12 days. The SOD

No abstract