Linking exogenous foliar application of glycine betaine and stomatal characteristics with salinity stress tolerance in cotton (Gossypium hirsutum L.) seedlings

Abstract

Background Glycine betaine (GB) plays a crucial role in plants responding to abiotic stresses. Studying the physiological response of cotton seedlings to exogenous GB under salt stress provides a reference for the application of GB to improve the resistance of cotton seedlings under salt stress. The purpose of this research is to examine the impacts of foliar-applied GB on leaf stomatal structure and characteristics, gas exchange and chlorophyll fluorescence characteristics and plant growth indicators of Gossypium hirsutum L. under NaCl stress conditions. Results Under the salinity of 150 mM, the four concentrations of GB are 0, 2.5, 5, and 7.5 mM, and the control (CK) was GB-untreated non-saline. Salt stress negatively affected leaf stomata as well as gas exchange and chlorophyll fluorescence and decreased plant growth parameters of cotton seedlings. The treatment with 5 mM GB significantly increased the evolution of photosynthetic rate (Pn), transpiration rate (Tr), intracellular CO2 concentration (Ci) and stomatal conductance (gs) compared to the GB-untreated saline treatment. The Exogenous foliar-applied GB has sustainably decreased the carboxylation efficiency (Pn/Ci) and water use efficiency (WUE). The concentration of 5 mM GB leads to a significant improvement of leaf stomatal characteristics. The leaf gas exchange attributes correlated positively with stomatal density (SD), stomatal length (SL) and stomatal with (SW). Conclusion The overall results suggested that exogenous foliar supplementation with GB can effectively alleviate the damage of salt stress to cotton seedlings. The effect of applying 5 mM GB could be an optional choice for protecting cotton seedlings from NaCl stress through promoting the stomatal functions, photosynthetic activities and growth characteristics.

The Differential Effects of Tuta absoluta Infestations on the Physiological Processes and Growth of Tomato, Potato, and Eggplant

“…A thick boundary layer leads to a low transpiration rate [ 41 ], which may explain the positive correlation for eggplant between plant height, transpiration, plant height, and conductance. Positive correlations for leaf gas exchange were also consistent with those obtained by Hamani et al [ 42 ] and Ibrahim et al [ 43 ].…”

Glycine betaine enhancing plant growth and antioxidant activity of fenugreek (Trigonella foenum-graecum L.) under salt stress

“…Nonetheless, GB mitigated the negative effects of the saline condition by inducing the expression of genes and enzymes that scavenge Reactive Oxygen Species (ROS) as well as membrane property protection. 24 Furthermore, Hamani et al, 9 demonstrated the importance of GB foliar application in cotton seedling stomatal conductance, transpiration rate, water use efficiency, photosynthesis rate, and photosystem II effectiveness under salinity. The increase in growth parameters as a result of foliar application of GB may be attributed to its ability to overcome the negative effect of salts in photosynthesis and to the increased production of assimilation units that promote growth.…”

“…8 Furthermore, exogenous GB application can improve growth rate under salinity by increasing stomatal conductance (gs), Relative Water Content (RWC), and chlorophyll content. 9 Previous research has shown that salt-tolerant plants can endogenously synthesize GB in excess to adjust salinity. 10 Exogenous application of GB to plants, such as adding to a nutrient solution or spraying for salinity resistance, is not capable of GB accumulation.…”

Coumarin-Mediated Growth Regulations, Antioxidant Enzyme Activities, and Photosynthetic Efficiency of Sorghum bicolor Under Saline Conditions

“…Various approaches have been adopted to mitigate the salinity-induced damages in crop plants, in which exogenous applications through seed priming and foliar spray of phytohormones, osmo-protectants, osmolytes, and antioxidants are considered cost-effective and eco-friendly ( Al-Huqail et al, 2020 ; Azeem et al, 2020 ). Exogenous application of these compounds such as salicylic acid ( Azeem et al, 2019 ; Ahmad et al, 2020 ), ascorbic acid, putrescine ( Seleem et al, 2021 ), polyamines ( Sagor et al, 2021 ), proline ( Ghafoor et al, 2019 ), glycine betaine ( Hamani et al, 2021 ), melatonin ( Ali et al, 2021 ), strigolactone ( Zulfiqar et al, 2021 ), and coumarin ( Sultana et al, 2020 ; Parvin et al, 2021 ) have found effective in improving plants salinity tolerance and biomass production.…”