Gamma-aminobutyric acid (GABA) alleviates salt damage in tomato by modulating Na+ uptake, the GAD gene, amino acid synthesis and reactive oxygen species metabolism
| Autor: | Li Jingrui, Jia Qiuying, Ji Shengxin, Xiaolei Wu, Gong Binbin, Hongbo Gao, Guiyun Lü |
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| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
0301 basic medicine China Glutamate decarboxylase Plant Science Biology 01 natural sciences Plant Roots gamma-Aminobutyric acid Tomato 03 medical and health sciences chemistry.chemical_compound Solanum lycopersicum Stress Physiological lcsh:Botany medicine Proline Amino acid synthesis Plant Proteins chemistry.chemical_classification Ions SlGAD transcriptional expression Amino acid accumulation Gamma-aminobutyric acid Reactive oxygen species metabolism Glutamate receptor food and beverages Metabolism Salt Tolerance Malondialdehyde lcsh:QK1-989 Amino acid Plant Leaves 030104 developmental biology NaCl stress Biochemistry chemistry Na+ flux and transportation Seedlings Reactive Oxygen Species 010606 plant biology & botany medicine.drug Research Article |
| Zdroj: | BMC Plant Biology BMC Plant Biology, Vol 20, Iss 1, Pp 1-21 (2020) |
| Popis: | Background Salt stress is a serious abiotic stress that caused crop growth inhibition and yield decline. Previous studies have reported on the the synthesis of gamma-aminobutyric acid (GABA) and its relationship with plant resistance under various abiotic stress. However, the relationship between exogenous GABA alleviating plant salt stress damage and ion flux, amino acid synthesis, and key enzyme expression remains largely unclear. We investigated plant growth, Na+ transportation and accumulation, reactive oxygen species (ROS) metabolism and evaluated the effect of GABA on amino acids, especially SlGADs gene expression and the endogenous GABA content of tomato (Solanum lycopersicum L.) seedlings treated with or without 5 mmol·L− 1 GABA under 175 mmol·L− 1 NaCl stress. Results Exogenous application of GABA significantly reduced the salt damage index and increased plant height, chlorophyll content and the dry and fresh weights of tomato plants exposed to NaCl stress. GABA significantly reduced Na+ accumulation in leaves and roots by preventing Na+ influx in roots and transportation to leaves. The transcriptional expression of SlGAD1–3 genes were induced by NaCl stress especially with GABA application. Among them, SlGAD1 expression was the most sensitive and contributed the most to the increase in glutamate decarboxylase (GAD) activity induced by NaCl and GABA application; Exogenous GABA increased GAD activity and amino acid contents in tomato leaves compared with the levels under NaCl stress alone, especially the levels of endogenous GABA, proline, glutamate and eight other amino acids. These results indicated that SlGADs transcriptional expression played an important role in tomato plant resistance to NaCl stress with GABA application by enhancing GAD activity and amino acid contents. GABA significantly alleviated the active oxygen-related injury of leaves under NaCl stress by increasing the activities of antioxidant enzymes and decreasing the contents of active oxygen species and malondialdehyde. Conclusion Exogenous GABA had a positive effect on the resistance of tomato seedlings to salt stress, which was closely associated with reducing Na+ flux from root to leaves, increasing amino acid content and strengthening antioxidant metabolism. Endogenous GABA content was induced by salt and exogenous GABA at both the transcriptional and metabolic levels. |
| Databáze: | OpenAIRE |
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