Title
Chromium mediated damaging effects on growth, nitrogen metabolism and chlorophyll synthesis in tomato can be alleviated by foliar application of melatonin and jasmonic acid priming
Author
Qin, Cheng
Publication
SCIENTIA HORTICULTURAE
Year
2024
Volume
323
Corresponding Author
Ahanger, MA
Abstract
Efficiency of methyl-jasmonate (5 mu M Me-J) priming and the foliar application of melatonin (100 mu M ML) in assuaging the deleterious effects of chromium (Cr) toxicity on growth, nitrogen metabolism, chlorophyll syn-thesis and photosynthesis in tomato were studied. Chromium toxicity reduced growth, chlorophyll synthesis and photosynthesis significantly, however Me-J and ML significantly enhanced the parameters. Decline in the in-termediates of chlorophyll biosynthesis pathway i.e., glutamate 1-semialdehyde, delta-amino levulinic acid, Mg-prototoporphyrin IX, prototoporphyrin IX and protochlorophyllide due to Cr was alleviated to considerable levels due to Me-J and ML treatment. Toxicity of Cr was evident as increased production of superoxide and hydrogen peroxide, and activity of lipoxygenase and protease while as Me-J and ML treatment alleviated the oxidative damage by causing significant decline in these parameters. Priming with Me-J and foliar application of ML alleviated the Cr toxicity induced decline in the activities of nitrogen metabolising enzymes. Treatment of Me-J and ML up-regulated the antioxidant system functioning, increased the content of secondary metabolites and activity of phenylalanine ammonia lyase. Accumulation of osmolytes increased due to Me-J and ML under normal as well as Cr toxicity conditions. Treatment of Me-J and ML increased the gamma-glutamyl kinase activity with significant reduction in proline oxidase.