Salicylic Acid Alleviates the Adverse of Salinity Stress in Fenugreek (Trigonella foenum-graecum)

Aims: To discover the resistance of the Yemeni genotype of fenugreek to salt stress and the impact of salicylic acid on alleviating salt stress.

Study Design: The experimental design adopted a completely randomized block design (RCBD), with pots filled with a 1:2 mixture of sand and soil serving as the experimental units.

Place and Duration of Study: in a mini greenhouse covered with white polyethylene plastic sheet at Taiz University during the spring season 2021. The average temperature ranged from 32 ℃ during the day to 29 ℃ at night. chemical analyses were performed at the pharmaceutical laboratory in Al-Saeed University.

Methodology: The fenugreek genotype was subjected to varying salinity levels (0, 50, 100, 150, and 200 mM) and the impact of salicylic acid (at concentrations of 0, 0.1, and 0.5 mg/l) in alleviating salt stress effects was examined at two time points: 15 and 30 days after 2 weeks of germination.

Results: Increasing salinity significantly reduced shoot and root length and exhibited slight fluctuations influenced by salinity levels above 100 mM. Salicylic acid (SA) significantly reduced shoot length but had no effect on root length. Salinity had no appreciable effect on shoot dry matter (SDM%), while the application of SA significantly decreased it. Root dry matter percentage (RDM%) showed a notable and sharp increase with salinity. However, no appreciable changes in RDM% were observed in response to the SA application. In response to salinity, the ratio of SDM% to RDM% in treated plants decreased sharply, with the lowest ratio achieved when 0.1 SA was used for treatment. There were no significant modifications observed in the amounts of photosynthetic pigments in fenugreek leaves, including chl a, chl b and total chl. Nevertheless, using high concentration of Nacl led to a signifcantly reduced in the carotenoids and the chl. b. The protein content of fenugreek plants treated with salt was much higher than that of control plants. Also, protein levels increased with SA treatment across all NaCl concentration. Proline levels sharply increased with rising salinity, reaching a peak in approximately 22.28 ug/g DW. Application of 0.1 SA led to the highest proline level in comparison to other treatments, which was the highest level of Nacl in the second measurement time. Proline levels in plants treated with 200 Nacl and 0.1 SA were the highest, averaging roughly recorded 49.95 ug/g DW. APX significantly affected on fenugreek plants, the highest APX content was found in plants treated with 50 mM NaCl, the application of 0.1 SA produced the highest level of APX (0.373nm/g protein/minuet) in fenugreek. Catalase (CA) levels significantly decreased, but SA application did not affect CA levels. The data obtained may help in determining fenugreek cultivation areas and in managing breeding programs.