Investigating the efficacy of tartaric acid and zinc-mediated endogenous melatonin induction for mitigating arsenic stress in Tagetes patula L.

Abstract

In order to enhance plant growth and productivity, various chemicals and substances are commonly employed, wherein their effectiveness is influenced by factors such as concentration and growth stage. This study aimed to investigate the impact of arsenic stress on Tagetes patula L. and evaluate the potential alleviating effects of zinc (Zn) and tartaric acid. The findings revealed that low concentrations of Zn and tartaric acid effectively protected Tagetes patula L. from the adverse effects of heavy metal stress. Zinc exhibited a crucial role in plant physiology by stimulating enzyme activity and defense mechanisms. Furthermore, moderate concentrations of Zn and tartaric acid were observed to promote plant growth and increase chlorophyll content. Notably, the combined application of Zn and tartaric acid exhibited the most significant improvements in plant morphology and chlorophyll levels. Additionally, the treatments with low concentrations of Zn and tartaric acid resulted in reduced oxidative stress, as evidenced by decreased levels of hydrogen peroxide and malondialdehyde (MDA) content. Moreover, the application of zinc and tartaric acid positively influenced total soluble protein levels and relative water content. The combined treatment also enhanced the activities of antioxidant enzymes, thereby mitigating oxidative damage induced by arsenic stress. Furthermore, the synergistic effect of the Zn and tartaric acid treatment effectively alleviated arsenic-induced oxidative stress and increased the concentration of melatonin. Proline accumulation exhibited an increase under various treatments, with the combination of Zn and tartaric acid showing the most favorable impact. The resting membrane potential (RMP) of the plants was influenced by different treatments, with consistent effects observed in the combined Zn and tartaric acid treatment. Additionally, the combination of targeted amendments (TA) and Zn treatments proved beneficial in reducing soil pollution indicators. In conclusion, the synergistic application of Zn and tartaric acid demonstrated promising effects in mitigating arsenic-induced stress and optimizing the growth and physiology of Tagetes patula plants.