Cotton leaf worm (Spodoptera littoralis) is considered one of the most destructive agricultural pests in Egypt. It is overcome by the producer by using chemical pesticides, but that leads to the appearance of new generations and causes environmental pollution. So in the present investigation six soybean genotypes (Giza-82, Giza 22, Giza 83, Giza 21, Giza 35 and Giza 111) were planted under natural infection with cotton leaf worm. The effect of two elicitors, methyl jasmonate (20 µM MeJA) and sodium nitroprusside (500 µM SNP) on the six soybean genotypes was studied to enhance the ability of the susceptible genotypes to resist cotton leaf worm. Results showed that Giza 35 and Giza 111 showed tolerance performance under natural infection compared to Giza 22 and Giza 82 as sensitive ones, while Giza 83 and Giza 21 showed moderate tolerance. Treatments with MeJA and SNP positively affected contents of secondary metabolites (phenol, flavonoid and tannin), non-enzymatic antioxidants (anthocyanin, tocopherol and ascorbic acid) and enzymatic antioxidants (catalase, peroxidase, polyphenol oxidase and Guaiacol peroxidase) in shoots of all soybean genotypes. Treatment with MeJA was found to be more effective than SNP and enhanced the resistance of the susceptible genotypes. In conclusion, treatment of soybean plants with MeJA and SNP would be effective enhancing the ability of these plants to resists cotton leaf worm infection and increased secondary metabolites and antioxidants responsible for plant defense.

棉叶虫（Spodoptera littoralis）被认为是埃及最具破坏力的农业害虫之一。生产者通过使用化学农药克服了这一问题，但这导致了新一代的出现，并造成了环境污染。因此，在本研究中，在棉叶虫自然感染下种植了六种大豆基因型（Giza-82，Giza 22，Giza 83，Giza 21，Giza 35和Giza 111）。研究了茉莉酸甲酯（20 µM MeJA）和硝普钠（500 µM SNP）这两种引发剂对六种大豆基因型的影响，以增强易感基因型抵抗棉虫的能力。结果表明，与敏感的吉萨22和吉萨82相比，吉萨35和吉萨111在自然感染下表现出耐受性，而吉萨83和吉萨21表现出中等耐受性。MeJA和SNP处理对所有大豆芽中次生代谢产物（苯酚，类黄酮和单宁），非酶抗氧化剂（花色素苷，生育酚和抗坏血酸）和酶抗氧化剂（过氧化氢酶，过氧化物酶，多酚氧化酶和愈创木酚过氧化物酶）的含量产生积极影响基因型。发现用MeJA治疗比SNP更有效，并增强了易感基因型的耐药性。总之，用MeJA和SNP处理大豆植物将有效增强这些植物抵抗棉虫感染的能力，并增加负责植物防御的次生代谢产物和抗氧化剂。多基因型芽中的多酚氧化酶和愈创木酚过氧化物酶）。发现用MeJA治疗比SNP更有效，并增强了易感基因型的耐药性。总之，用MeJA和SNP处理大豆植物将有效增强这些植物抵抗棉叶虫感染的能力，并增加负责植物防御的次生代谢产物和抗氧化剂。多基因型芽中的多酚氧化酶和愈创木酚过氧化物酶）。发现用MeJA治疗比SNP更有效，并增强了易感基因型的耐药性。总之，用MeJA和SNP处理大豆植物将有效增强这些植物抵抗棉虫感染的能力，并增加负责植物防御的次生代谢产物和抗氧化剂。