Assessment of Morpho-Physiological, Biochemical and Antioxidant Responses of Tomato Landraces to Salinity Stress

Abstract

Understanding salt tolerance in tomato (Solanum lycopersicum L.) landraces will facilitate their use in genetic improvement. The study assessed the morpho-physiological variability of Hail tomato landraces in response to different salinity levels at seedling stages and recommended a tomato salt-tolerant landrace for future breeding programs. Three tomato landraces, Hail 548, Hail 747, and Hail 1072 were tested under three salinity levels: 75, 150, and 300 mM NaCl. Salinity stress reduced shoots’ fresh and dry weight by 71% and 72%, and roots were 86.5% and 78.6%, respectively. There was 22% reduced chlorophyll content, carotene content by 18.6%, and anthocyanin by 41.1%. Proline content increased for stressed treatments. The 300 mM NaCl treatment recorded the most proline content increases (67.37 mg/g fresh weight), with a percent increase in proline reaching 61.67% in Hail 747. Superoxide dismutase (SOD) activity decreased by 65% in Hail 548, while it relatively increased in Hail 747 and Hail 1072 treated with 300 mM NaCl. Catalase (CAT) activity was enhanced by salt stress in Hail 548 and recorded 7.6%, increasing at 75 and 5.1% at 300 mM NaCl. It revealed a reduction in malondialdehyde (MDA) at the 300 mM NaCl concentration in both Hail 548 and Hail 1072 landraces. Increasing salt concentrations showed a reduction in transpiration rate of 70.55%, 7.13% in stomatal conductance, and 72.34% in photosynthetic rate. K+/Na+ ratios decreased from 56% for 75 mM NaCl to 85% for 300 mM NaCl treatments in all genotypes. The response to salt stress in landraces involved some modifications in morphology, physiology, and metabolism. The landrace Hail 548 may have better protection against salt stress and observed protection against reactive oxygen species (ROS) by increasing enzymatic “antioxidants” activity under salt stress.

Crataegus oxyacantha Extract as a Biostimulant to Enhance Tolerance to Salinity in Tomato Plants

“…Our results showed that the tomato plants that were exposed to salt stress had significantly decreased shoot length and fresh weight compared to the control plants. These results agreed with those obtained by Alzahib et al (2021) [ 15 ], in which a high concentration of NaCl (0.3 M) decreased tomato plant growth, leaf area, plant height, and fresh and dry root weights.…”

Mitigation of Salinity-Induced Oxidative Damage, Growth, and Yield Reduction in Fine Rice by Sugarcane Press Mud Application

“…Excessive Na + ions participate in ROS production by working as signaling molecules in transduction pathways ( Fatima et al, 2021 ). The excessive accumulation of Na + denatures the enzyme needed to synthesize chlorophyll and therefore reduces the synthesis of chlorophyll ( Alzahib et al, 2021 ). However, PM alleviated this reduction, which indicates PM application reduced the excessive Na + accumulation, which protects photosynthetic apparatus from damaging effects of Na + and reduces the activities of chlorophyll degrading enzymes, improving chlorophyll synthesis under salinity stress ( Sheoran et al, 2021a ).…”

Physiological response and proteomics analysis of Reaumuria soongorica under salt stress

“…In addition, the generation and transport of biomass is also an important factor in assessing the degree of salt stress in plants 26 . Studies have shown that salt stress reduces plant biomass synthesis, and that plant leaves are capable of responding to salt stress via the rapid accumulation of proline 27 – 29 . In our experiment, under the stress condition of low salt B (200 mM NaCl), the fresh weight and root/shoot ratio of R. soongorica seedlings increased, and low salt had a significant promotional effect on their growth.…”