Cutaneous secretions produced by amphibians of the family Bufonidae are rich sources of bioactive compounds that can be useful as new chemical templates for agrochemicals. In crop protection, the use of elicitors to induce responses offers the prospect of durable, broad-spectrum disease control using the plant’s own resistance. Therefore, we evaluated the potential of methanolic extracts of cutaneous secretions of two species of amphibians of the family Bufonidae found in the Amazon biome—Rhaebo guttatus (species 1) and Rhinella marina (species 2)—in the synthesis of phytoalexins in soybean cotyledons, bean hypocotyls, and sorghum mesocotyls. Additionally, changes in the enzyme activity of β-1,3-glucanase, peroxidase (POX), and polyphenol oxidase (PPO) and in the total protein content of soybean cotyledons were determined. In the soybean cultivar ‘TMG 132 RR’, our results indicated that the methanolic extract of R. guttatus cutaneous secretions suppressed glyceollin synthesis and β-1,3-glucanase activity and increased POX and PPO activities at higher concentrations and total protein content at a concentration of 0.2 mg/mL. On the other hand, the methanolic extract of R. marina cutaneous secretions induced glyceollin synthesis in the soybean cultivars ‘TMG 132 RR’ and ‘Monsoy 8372 IPRO’ at 0.1–0.2 mg/mL and 0.2 mg/mL, respectively. The methanolic extract of R. marina cutaneous secretions also increased the specific activity of POX and PPO in ‘Monsoy 8372 IPRO’ and ‘TMG 132 RR’, respectively, and decreased the activity of β-1,3-glucanases in ‘Monsoy 8372 IPRO’. At 0.3 mg/mL, it stimulated phaseolin synthesis. The extracts did not express bioactivity in the synthesis of deoxyanthocyanidins in sorghum mesocotyls. The study in soybean suggests that the bioactivity in defense responses is influenced by cultivar genotypes. Therefore, these results provide evidence that extracts of cutaneous secretions of these amphibians species may contribute to the bioactivity of defense metabolites in plants.

蟾蜍科两栖动物产生的皮肤分泌物是丰富的生物活性化合物的来源，可用作农业化学品的新化学模板。在作物保护中，使用激发子诱导反应提供了利用植物自身的抗药性进行持久，广谱疾病控制的前景。因此，我们评估了在亚马逊生物群系中发现的Bufonidae科的两种两栖动物的皮肤分泌物甲醇提取物的潜力，即Rhaebo guttatus（物种1）和Rhinella marina（第2种）—在大豆子叶，大豆下胚轴和高粱中胚轴中合成植物抗毒素。另外，测定了β-1，3-葡聚糖酶，过氧化物酶（POX）和多酚氧化酶（PPO）的酶活性以及大豆子叶总蛋白含量的变化。在大豆品种“ TMG 132 RR”中，我们的结果表明R的甲醇提取物。鱯皮肤分泌物抑制大豆抗毒素合成和β-1,3-葡聚糖酶活性，并在更高的浓度和总蛋白含量增加POX和PPO活性以0.2mg / mL的浓度。另一方面，R的甲醇提取物。码头皮肤分泌物分别以0.1–0.2 mg / mL和0.2 mg / mL的大豆品种'TMG 132 RR'和'Monsoy 8372 IPRO'诱导甘油三醇合成。R的甲醇提取物。码头皮肤分泌物还分别增加了“ Monsoy 8372 IPRO”和“ TMG 132 RR”中POX和PPO的比活性，并降低了“ Monsoy 8372 IPRO”中β-1,3-葡聚糖酶的活性。在0.3 mg / mL时，它会刺激菜豆素的合成。提取物在高粱中胚轴中的脱氧花青素合成中不表达生物活性。在大豆中的研究表明，防御反应中的生物活性受品种基因型的影响。因此，这些结果提供了证据，表明这些两栖动物物种的皮肤分泌物提取物可能有助于植物防御代谢产物的生物活性。