Potassium supplementation mitigates flooding stress by regulating antioxidant enzymes, photosynthetic performance, yield attributes, and lint quality in cotton plants

Abstract

Flooding stress declines oxygen availability in roots that induce hypoxia stress in plants, thereby severely decline plant growth. Study was undertaken to clarify how potassium supplementation alleviates flooding stress in cotton plants. We applied potassium (K) fertilizer in pot soils at different levels; K 0 = Control (No K), K 1 = 30 mg kg−1, K 2 = 60 mg kg−1 and K 3 = 80 mg kg−1 with different duration of flooding stress s. D 0 = Normal irrigation (0 day flooding), D 1 = three days flooding, D 2 = six days flooding, D 3 = nine days flooding, D4 = twelve days flooding. The K supplementation (80 mg kg−1) in soil with 3-day flooding stress showed better combination for mitigating flooding stress. The supplementation of K3 dose (80 mg kg−1) alleviated flooding against 3-day initial flooding (D1) of which physiological traits showed better response compared to prolonged flooding stress (12-day flooding stress). The result suggests that K-involving flooding stress mitigation strategy in cotton plants was active for initial flooding stress (3-day flooding stress), while it was not fully active for pronged (upto 12-day flooding stress). Furthermore, we found K significantly improved antioxidant enzymes, photosynthetic performance, yield attributes, and lint quality.