The phytoelicitor and phytostimulatory properties of alkaline extracts of two tropical seaweeds, Sargassum vulgare C. Agardh and Acanthophora spicifera (M.Vahl) Børgesen, collected from the coasts of Trinidad were investigated in tomato and sweet pepper crops. Foliar applications of seaweed extracts (SWE), at 0.5% concentration, resulted in substantial reductions in disease severity by the pathogens, Xanthomonas campestris pv. vesicatoria and Alternaria solani under greenhouse and field conditions. The effects of SWE on disease suppression were significantly improved when integrated with a minimum dose of fungicide. SWE-treated plants also showed enhanced plant growth and yield parameters. Investigations into the modes of action for disease suppressive effects revealed that SWE-treated plants had sustainably augmented defense enzyme activities and phenolic levels. The activation of defense pathways was validated by confirming the upregulation of marker gene transcripts (PR-1a, PinII, and ETR-1) which are involved in defense signalling pathways. The SWE-treated plants also showed significant upregulation of genes involved in auxin (IAA), gibberellin (Ga2Ox), and cytokinin (IPT) biosynthesis. Multiple applications of SWE in crop plants have minimized the need for chemical fungicide sprays. The current study demonstrates the applicability of tropical SWE for use in vegetable plants for achieving environmental-friendly and sustainable crop production.

所述phytoelicitor和两个热带海藻的碱性提取物phytostimulatory性能，羊栖菜大麦C. Agardh和Acanthophora spicifera（M.Vahl）Børgesen ，特立尼达海岸收集在番茄和甜椒作物进行了调查。叶面使用浓度为0.5％的海藻提取物（SWE）导致病原体Xanthomonas campestris pv大大降低了疾病的严重程度。vesicatoria和链格孢在温室和田间条件下。当与最小剂量的杀菌剂结合使用时，SWE对疾病抑制的作用得到了显着改善。经SWE处理的植物还显示出增强的植物生长和产量参数。对抑制疾病的作用方式的研究表明，经SWE处理的植物具有可持续增强的防御酶活性和酚水平。通过确认参与防御信号通路的标志物基因转录物（PR-1a，PinII和ETR-1）的上调来验证防御通路的激活。经SWE处理的植物还显示出与生长素（IAA），赤霉素（Ga2Ox）有关的基因的显着上调）和细胞分裂素（IPT）的生物合成。SWE在农作物中的多种应用使对化学杀菌剂喷雾的需求降至最低。当前的研究表明，热带SWE可用于蔬菜植物中，以实现环境友好和可持续的农作物生产。