Salicylic acid mitigating damage to the photosynthetic apparatus and quality of Eugenia myrcianthes seedlings under water deficit

Abstract

This study aimed to evaluate the effect of exogenous application of salicylic acid on the photosynthetic metabolism and quality of Eugenia myrcianthes seedlings under water deficit and their recovery potential after rehydration. Two water regimes were evaluated, as follows: control - plants irrigated daily (I) and water deficit (S), with and without the application of 400 mg L–1 of salicylic acid (SA), totaling four treatments. Seedlings were evaluated at three times: at the beginning of the experiment (T0), that is, when the irrigation was interrupted; when the photosynthetic rate reached values close to zero (P0 - 15 days after irrigation interruption), that is, when irrigation restarted; and when the photosynthetic rate was recovered (REC). Eugenia myrcianthes seedlings were negatively affected when subjected to water restriction; salicylic acid attenuated the damage to the photosynthetic apparatus by acting positively on the relative water content in the leaves, SPAD index, photosynthetic metabolism, superoxide dismutase and peroxidase enzyme activity, and seedling growth in P0. Eugenia myrchiantes presented potential for recovery after resumption irrigation. The application of SA contributed to the maintenance of gas exchanges, photochemical processes and quality of E. myrcianthes seedlings during and after water deficit, suggesting the promotion of plant resistance induction.

Salicylic acid on gas exchange and growth of Hymenaea courbaril L. seedlings under flooding

“…As for SA, the results of this study with H. courbaril differ from those in the literature, which reports that this phytohormone plays a role in metabolic regulation and alleviation of stress factors in the photosynthetic apparatus (Foresti et al, 2022;Santos et al, 2022b), as its application accentuated the reduction of A in H. courbaril seedlings.…”

“…Generally, plants under flooding tend to have lower RL due to rotting and root disruption, but for H. courbaril, our results suggest that the * -Significant at p ≤ 0.05 species has the ability to adjust its root system to this condition, considering the exposure time to flooding. Based on the results of this study, it is suggested that SA acts as a growth regulator in both leaf and root areas, as observed in the literature (Bagautdinova et al, 2022;Foresti et al, 2022), but at a dose lower than 200.0 mg L -1 .…”

“…Variable results were observed regarding the species in response to SA, although there are few studies on tree and fruit species, especially from the same botanical family. For E. myrcianthes assimilation CO 2 rate increases, while seedling growth did not change (Foresti et al, 2022). In Psidium guajava L., SA concentrations did not influence gas exchange or fruit growth (Lacerda et al, 2022).…”

“…Cultivation management techniques that can mitigate the possible damage caused by flooding on plant metabolism have been developed. Among the promising alternatives, foliar application of salicylic acid (SA), a phenolic phytohormone, can alleviate the negative effects of abiotic stresses by contributing to the antioxidant system, metabolic regulation, and plant growth (Saracho et al, 2021;Foresti et al, 2022;Santos et al, 2022b).…”