Chilling Tolerance Enhancement in Tomato (Solanum lycopersicum) By Exogenous Application of Aspirin

Abstract

Two pot experiments were conducted during two growing seasons 2017/2018 and 2018/2019 at the green house of the National Research Centre, Dokki, Giza, Egypt. To improve cold tolerance, acetyl salicylic acid (aspirin) (1, 2 mM) was investigated. The work focused on study the effect of aspirin (ASA) on growth criteria (plant height, number of leaves, fresh and dry weights of leaves and root of tomato/plant), total soluble Protein, total chlorophyll, antioxidant enzyme (APX, GR, Gly1) activities and specific activities, super oxide (O2ˉ), electrolyte leakage, and yield. Obtained results revealed that plants grown under low temperature and foliarly treated after transplanting with ASA at the concentration of 2mM followed by 1mM mitigated the harmful effects of low temperature stress through the enhancement of their protective parameters, such as antioxidant enzymes activity, total soluble protein and total chlorophyll. ASA at 2mM recorded the highest increments in growth criteria, APX, GR, GlyI activities and specific activities, total soluble protein, total chlorophyll and total soluble solids. Remarkable decreases were also obtained in O2ˉ and electrolyte leakage (EL) with the used concentration of aspirin treatments. The results also, showed that the highest value of yield per plant was recorded with plants received aspirin at the concentration of 2mM. Based on the obtained results, it could be suggested that the protection mechanism had helped the plants to increase their resistance against chilling stress, through mainly the decrease in membrane damage symptoms leading to intercellular osmotic adjustment.