GABA accumulation and oxidative damage responses to salt, osmotic and H₂O₂ treatments in two lentil (Lens culinaris Medik) accessions

Abstract

Abiotic stresses such as cold, drought, heat, salinity, nutrient deficiency, and toxicity adversely affect lentil yields worldwide. Therefore, the purpose of this study was to investigate the response of two lentil cultivars (Lens culinaris Medik) (Jordan 1 and Jordan 2) to NaCl, mannitol, sorbitol, and H₂O₂ via the characterization of seed germination, accumulation of reactive oxygen species, and γ-aminobutyric acid (GABA) level. There was a significant increase in GABA and malondialdehyde (MDA) levels in the two lentil cultivars under all treatments. Jordan 1 showed the highest germination percentages with p-values: 0.009, 0.013, 0.026, and 0.015, while Jordan 2 seedlings showed the highest GABA levels with p-values: 0.023, 0.007, 0.023, and 0.019 and MDA accumulation with p-values: 0.009, 0.012, 0.007, and 0.009 under salt, osmotic, and oxidative stresses, respectively, compared with Jordan 1 seedlings under the same treatments. Our results indicate that GABA shunt is a key signaling and metabolic pathway that allows adaptation of lentil seedlings to salt, osmotic, and oxidative stresses. In addition, Jordan 1 cultivar showed significant tolerance to abiotic stress treatments and it is the most recommended lentil cultivar to be used in soil with high salt and osmotic contents.

Keywords:

• γ-Aminobutyric acid (GABA)
• H₂O₂
• lentil
• mannitol
• NaCl
• oxidative stress
• sorbitol
• stress

Funding

This work was supported by the Deanship of Research, Jordan University of Science and Technology, Jordan [grant number 96/2011].