The olive production is limited by the important factor of winter freezing damage. The purpose of this research was to investigate the probable role of exogenously applied methyl jasmonate (MeJA; 0.02, 0.1, and 0.2 mM) and 24–epibrassinolide (EBR; 0.2, 0.4, and 0.6 μM) to alleviate the adverse effect of freezing stress in olive (Olea europaea L. cv. Koronieki) leaves, which was conducted in a research orchard. Furthermore, some physiological and biochemical changes were studied in olive leaves at six sampling dates, and their relationship with freezing tolerance (expressed as LT₅₀) were investigated. The results indicated that the olives freezing tolerance, soluble carbohydrates, proline, total soluble proteins, antioxidant enzymes, DPPH radical scavenging capacity, as well as total phenolic content were significantly increased using the foliar application of MeJA and EBR. The highest and lowest freezing tolerance in EBR 0.6 μM and control olives was as much as –8.22 °C and–6.87 °C, respectively. The LT₅₀ profile had a significant negative correlation with accumulation of some compounds such as leaf soluble carbohydrates, total soluble protein, total phenolic content, DPPH scavenging capacity, as well as activating the catalase enzyme. Moreover, EBR 0.6 μM and control treatments respectively had the highest and lowest ratio between unsaturated fatty acids and saturated fatty acids (UFA/SFA ratio), especially in January. It can be concluded that the freezing tolerance of olive leaves can be increasing by the foliar application of MeJA and EBR treatments, which can be utilized as a preventive instrument to decrease freezing damage.

橄榄的产量受到冬季冻害的重要因素的限制。这项研究的目的是研究外用茉莉酸甲酯（MeJA； 0.02、0.1和0.2 mM）和24-表油菜素内酯（EBR； 0.2、0.4和0.6μM）减轻冷冻压力的不利影响的可能作用。在研究果园中进行的橄榄叶（Olea europaea L. cv。Koronieki）叶中进行。此外，在六个采样日期对橄榄叶的一些生理和生化变化进行了研究，并研究了它们与耐寒性的关系（表示为LT ₅₀）进行了调查。结果表明，叶面施用MeJA和EBR可以显着提高橄榄的耐冻性，可溶性碳水化合物，脯氨酸，总可溶性蛋白，抗氧化酶，DPPH自由基清除能力以及总酚含量。EBR 0.6μM和对照橄榄的最高和最低冷冻耐受性分别高达–8.22°C和–6.87°C。LT ₅₀形态与某些化合物的积累具有显着的负相关性，例如叶片可溶性碳水化合物，总可溶性蛋白，总酚含量，DPPH清除能力以及激活过氧化氢酶。此外，EBR 0.6μM和对照处理分别具有最高和最低的不饱和脂肪酸和饱和脂肪酸比率（UFA / SFA比率），尤其是在一月份。可以得出结论，通过叶面施用MeJA和EBR处理，可以提高橄榄叶的抗冻性，可以将其用作减少冻害的预防手段。