Plant Stress (Mar 2024)
Enhancing salt stress tolerance in kidney beans: The synergistic effects of biochar and salicylic acid in arid and semi-arid regions
Abstract
Salt stress is one of the most damaging environmental stresses of recent times and poses a significant threat to food security. Here, we conducted an experimental study over two consecutive years (2022–2023) to evaluate the physiological and biochemical characteristics of kidney beans. The study used a randomized complete block design with 4 replications (n = 4). The experiment included three levels of salicylic acid (SA): SA0 (0 mM), SA0.5 (0.5 mM) and SA1 (1 mM). The study also used biochar in four levels, without biochar as the control treatment (B0), regular biochar (Rb) by 2.5 % per soil weight, modified biochar with phosphoric acid (PA) by 1.25 % per soil weight, and modified biochar with sulfuric acid (Sb) by 1.25 % per soil weight. Additionally, salt stress (SS) was induced using NaCl in three levels, SS0 (distilled water), SS4 (4 4 dS m−1), and SS8 (8 dS m−1). The results showed that salt stress, biochar, and salicylic acid significantly affected the measured parameters. Salt stress (SS4 and SS8) negatively affected the measured parameters compared to the control. However, the application of biochar and salicylic acid regulated the alleviation of the impact of salt stress. Under SS4, the application of Rb along with SA1 resulted in the highest value of proline content. The highest enzymatic activity of catalase was observed due to the use of PA in combination with SA0.5 under non-saline soil conditions. The use of PA under SS8 increased the hydrogen peroxide and caused the highest activity, while the lowest activity was obtained under non-saline soil conditions with the application of Sb. In the first year of the experiment, it was found that the use of SA1 without biochar under non-stress conditions resulted in the highest levels of malondialdehyde. Likewise, in the second year, the highest malondialdehyde activity was observed by applying Rb and SA1 under SS8. The research concludes that kidney bean plants are significantly impacted by salt stress, which affects their biochemical characteristics. Nonetheless, the combined application of biochar and salicylic acid showed promise in addressing these challenges. This approach could be particularly effective in managing salinity issues in arid and semi-arid regions, highlighting the potential of biochar and salicylic acid for improving plant resilience under such conditions.
