Salicylic acid mitigates water deficit and improves the recovery of Hymenaea courbaril seedlings¹

Ácido salicílico atenua déficit hídrico e melhora recuperação de mudas de Hymenaea courbaril

The potential of salicylic acid (SA) to mitigate water stress in Hymenaea courbaril was evaluated, analyzing the photosynthetic physiology, defense by antioxidant agents, the quality of seedlings, and the potential for recovery of seedlings after irrigation. Seedlings received foliar application of five concentrations of SA (0, 100, 200, 300, and 400 mg L^-1). Seedlings were grown under two water regimes: continuous irrigation (control), and water deficit (SI), characterized by irrigation suspension, associated with the following evaluation periods: P0 (when the photosynthetic rate of seedlings submitted to irrigation restriction reached values close to zero) and Rec (after P0, irrigation was resumed until the photosynthetic rate of seedlings previously submitted to water deficit reached values close to that of control plants), composing four treatments of association of water regime with evaluation periods (RHP): control I, P0 SI, control II and Rec SI. H. courbaril seedlings negatively responded to water deficit, with significant reduction in photosynthetic rate, stomatal conductance and growth, and with an increase in antioxidant and protective activity, after re-irrigation only. Foliar SA application of 400 mg L^-1 mitigated the effect of water restriction on gas exchange, leaf area, and seedling quality, also favoring their recovery after irrigation resumption by increasing the activity of antioxidant enzymes.

Key words:
Jatoba; abiotic stress; gas exchange; antioxidant enzymes; seedling quality

Hymenaea courbaril seedlings are sensitive to water restriction.

The foliar application of salicylic acid mitigated water deficit effects in gas exchange. The foliar application of salicylic acid improved seedling recovery after re-irrigation.