Exogenous γ-Aminobutyric Acid Can Improve Seed Germination and Seedling Growth of Two Cotton Cultivars under Salt Stress

Zhiduo Dong; Jian Huang; Tong Qi; Ajing Meng; Qiuping Fu; Yanbo Fu; Fei Xu

doi:10.3390/plants13010082

Exogenous γ-Aminobutyric Acid Can Improve Seed Germination and Seedling Growth of Two Cotton Cultivars under Salt Stress

Plants (Basel). 2023 Dec 26;13(1):82. doi: 10.3390/plants13010082.

Authors

Zhiduo Dong^{1

2}, Jian Huang^{2

3}, Tong Qi^{2

3

4}, Ajing Meng^{2

3}, Qiuping Fu¹, Yanbo Fu^{2

5}, Fei Xu^{2

5}

Affiliations

¹ College of Water Conservancy and Civil Engineering, Xinjiang Agricultural University, Urumqi 830052, China.
² Institute of Soil Fertilizer, Agricultural Water Saving, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China.
³ Key Laboratory of Saline-Alkali Soil Improvement and Utilization (Saline-Alkali Land in Arid and Semi-Arid Regions), Ministry of Agriculture and Rural Affairs, Urumqi 830091, China.
⁴ College of Land Science and Technology, China Agricultural University, Beijing 100193, China.
⁵ National Soil Quality Aksu Observation Experimental Station, Aksu 843000, China.

Abstract

Excessive salt content in soil has adverse effects on cotton production, especially during the germination and seedling stages. γ-aminobutyric acid (GABA) is an important active substance that is expected to improve the resistance of plants to abiotic stresses. This study focused on two cotton cultivars (Gossypium hirsutum L.: Tahe 2 and Xinluzhong 62) and investigated the impact of exogenous GABA (0, 1, 2, 3, and 4 mM) on seed germination, seedling growth, and related morphological, physiological, and biochemical indicators under salt stress (150 mM NaCl). The results showed that salt stress significantly reduced the germination rate and germination index of cotton seeds (decreased by 20.34% and 32.14% for Tahe 2 and Xinluzhong 62, respectively), leading to decreased seedling height and biomass and causing leaf yellowing. Salt stress induced osmotic stress in seedlings, resulting in ion imbalance (marked reduction in K⁺/Na⁺ ratio) and oxidative damage. Under salt stress conditions, exogenous GABA increased the germination rate (increased by 10.64~23.40% and 2.63~31.58% for Tahe 2 and Xinluzhong 62, respectively) and germination index of cotton seeds, as well as plant height and biomass. GABA treatment improved leaf yellowing. Exogenous GABA treatment increased the content of proline and soluble sugars, with varying effects on betaine. Exogenous GABA treatment reduced the Na⁺ content in seedlings, increased the K⁺ content, and increased the K⁺/Na⁺ ratio (increased by 20.44~28.08% and 29.54~76.33% for Tahe 2 and Xinluzhong 62, respectively). Exogenous GABA treatment enhanced the activities of superoxide dismutase and peroxidase, and reduced the accumulation of hydrogen peroxide and malondialdehyde, but had a negative impact on catalase activity. In conclusion, exogenous GABA effectively improved cotton seed germination. By regulating osmoprotectant levels, maintaining ion homeostasis, and alleviating oxidative stress, GABA mitigated the adverse effects of salt stress on cotton seedling growth.

Keywords: Gossypium; ion content; osmoregulation; oxidative stress.

Abstract

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