Potential Benefits of Seed Priming under Salt Stress Conditions on Physiological, and Biochemical Attributes of Micro-Tom Tomato Plants

Abstract

Pre-sowing seed priming is one of the methods used to improve the performance of tomato plants under salt stress, but its effect photosynthesis, yield, and quality have not yet been well investigated. This experiment aimed to alleviate the impact of sodium chloride stress on the photosynthesis parameters of tomato cv. Micro−Tom (a dwarf Solanum lycopersicum L.) plants exposed to salt stress conditions. Each treatment combination consisted of five different sodium chloride concentrations (0 mM, 50 mM, 100 mM, 150 mM, and 200 mM) and four priming treatments (0 MPa, −0.4 MPa, −0.8 MPa, and −1.2 MPa), with five replications. Microtome seeds were subjected to polyethylene glycol (PEG6000) treatments for 48 hours for priming, followed by germination on a moist filter paper, and then transferred to the germination bed after 24 h. Subsequently, the seedlings were transplanted into the Rockwool, and the salinity treatments were administered after a month. In our study salinity significantly affected tomato plants’ physiological and antioxidant attributes. Primed seeds produced plants that exhibited relatively better photosynthetic activity than those grown from unprimed seeds. Our findings indicated that priming doses of −0.8 MPa and −1.2 MPa were the most effective at stimulating tomato plant photosynthesis, and biochemical contents under salinity-related conditions. Moreover, primed plants demonstrated relatively superior fruit quality features such as fruit color, fruit Brix, sugars (glucose, fructose, and sucrose), organic acids, and vitamin C contents under salt stress, compared to non-primed plants. Furthermore, priming treatments significantly decreased the malondialdehyde, proline, and hydrogen peroxide content in plant leaves. Our results suggest that seed priming may be a long-term method for improving crop productivity and quality in challenging environments by enhancing the growth, physiological responses, and fruit quality attributes of Micro-Tom tomato plants under salt stress conditions.

Alleviating Salt Stress in Tomatoes through Seed Priming with Polyethylene Glycol and Sodium Chloride Combination

“…One of the key advantages of seed priming is its ability to enhance osmolyte accumulation within plant cells. Osmolytes such as proline, glycine betaine, and soluble sugars are like cellular superheroes, helping plants maintain water balance and structural integrity during stressful conditions like salinity [3,25]. When seeds are primed, they kickstart the production of these crucial compounds, essentially equipping plants with a built-in defense mechanism against water scarcity and osmotic stress.…”

“…The concentrations of the seed priming reagents were determined based on previous research findings. The concentration of PEG6000 was selected according to the study by Habibi et al [3], while for NaCl, Nakaune et al demonstrated that a concentration of 300 mM can enhance seedling vigor and other characteristics in tomatoes [18]. However, for a combined treatment of seed priming reagents, 300 mM NaCl was a high dose.…”

“…Salt stress poses a significant challenge in the cultivation of tomatoes, impacting various growth parameters [1,2] and physiological processes within the plants [3][4][5]. High salinity levels can lead to osmotic stress, disrupting the normal physiology of plants leading to cellular damage [6] and hindering normal metabolic activities.…”

“…Previous studies have investigated the varied impacts of salt stress on tomato plants. Seed priming with PEG6000 has been proven to efficiently induce salt tolerance in tomatoes [3,17]. Additionally, using sodium chloride as a priming reagent has shown effectiveness in reducing the negative effects of salt stress on tomato plants [18].…”