Synergistic effects of gamma-aminobutyric acid and melatonin on seed germination and cadmium tolerance in tomato

ABSTRACT

The effects of exogenous γ-aminobutyric acid (GABA) and melatonin (MT) on tomato seed germination and shoot growth exposed to cadmium stress were investigated. On the one hand, treatment with MT (10–200 μM) or GABA (10–200 μM) alone could significantly relieve cadmium stress in tomato seedlings, which is reflected in increasing the germination rate, vigor index, fresh weight, dry weight and radicle lengths of tomato seeds, as well as the soluble content compared to the absence of exogenous treatment, and the alleviating effect reached the peak in the 200 µM GABA or 150 µM MT alone. On the other hand, exogenous MT and GABA showed synergistic effects on the germination of tomato seed under cadmium stress. Moreover, the application of 100 µM GABA combined with 100 µM MT markedly decreased the contents of Cd and MDA by upregulating the activities of antioxidant enzymes, thereby alleviating the toxic effect of cadmium stress on tomato seeds. Collectively, the combinational strategy showed significant positive effects on seed germination and cadmium stress resistance in tomato.

KEYWORDS:

• Tomato
• seed germination
• cadmium stress
• γ-aminobutyric acid
• melatonin

Author contributions

JL and LY conceived the experiments. YL performed the experiments and drafted the manuscript. YZ conducted formal analysis, wrote, reviewed and edited the manuscript. YH, JW participated in the main experiments in this work, with assistance from FH. YZ and XC helped YL to did the data analysis. All authors read and approved the final manuscript.

Consent to participate

All authors give their consent to participate.

Consent for publication

All authors consent to publication.

Competinginterests

The authors have no conflicts of interest to declare.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Yunnan Provincial Science and Technology Department (2019FH001-008, 2018HB100) and Project of China National Tobacco Corporation Yunnan Branch (No. 2021530000242023, 2021530000242017, 2020530000242028).