Controlling plant diseases is essential to the long-term viability of agriculture. As the most significant global agricultural liability, fungal phytopathogens infect a widespread array of host plants and epitomize a substantial menace to plant species. Appropriate solutions are needed in contemporary agriculture to solve the current trend of agricultural and food insecurity challenges. The use of bioproducts, including seaweeds, is one potential lever to encourage this transition. Alginates, laminarins, ulvans, phenols, and carrageneans are seaweed metabolites and chemicals that have been shown to have direct antifungal properties. These substances limit the growth of the fungi by breaking down their cell walls and causing oxidative stress. This provides considerable disease control in plants at an early stage and substantially lowers the incidence of disease. It is believed that by starting a cross-talk between the defense pathway and phytohormone, seaweed oligosaccharides and ulvans stimulate synthesis of plant protective compounds as well as physiological changes that prevent pathogen entry like lignification or accumulate cell wall degrading enzymes (chitinase or glucanase) or antimicrobial compounds (phenols, salicylic acid) at the sites of infection. This activates the ethylene, jasmonic, and salicylic acid pathways, which in turn increases the synthesis of several plant defense chemicals and activates pathogenesis-related genes (PR 1–3). Effective disease management has been facilitated by increased oxidative enzyme production to avoid oxidative stress induced by pathogen entry also. Rather than a single mechanism for disease control, seaweed compounds instigate a cascade of reactions that activate plant defense offering multifold resistance and protection against phytopathogenic fungi. This substantially facilitates a benign environment for plant growth, positively influencing the nutritional status of plant products and yield, in an economic as well as sustainable manner.

中文翻译：

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海洋杂草对抗真菌植物病原体 - 当前的农艺影响和可持续未来的有趣前景

控制植物病害对于农业的长期生存至关重要。作为全球最重要的农业责任，真菌植物病原体感染广泛的寄主植物，并对植物物种构成重大威胁。当代农业需要适当的解决方案来解决当前农业和粮食不安全挑战的趋势。包括海藻在内的生物产品的使用是鼓励这一转变的潜在杠杆。海藻酸盐、昆布多糖、绿藻硫化多糖、酚类和卡拉胶是海藻代谢物和化学物质，已被证明具有直接抗真菌特性。这些物质通过破坏细胞壁并引起氧化应激来限制真菌的生长。这在早期阶段为植物提供了相当大的疾病控制，并大大降低了疾病的发生率。据信，通过启动防御途径和植物激素之间的串扰，海藻寡糖和绿藻硫化多糖刺激植物保护化合物的合成以及防止病原体进入的生理变化，如木质化或积累细胞壁降解酶（几丁质酶或葡聚糖酶）或感染部位的抗菌化合物（酚类、水杨酸）。这会激活乙烯、茉莉酸和水杨酸途径，进而增加多种植物防御化学物质的合成并激活发病机制相关基因 (PR 1-3)。增加氧化酶的产生也有助于有效的疾病管理，以避免病原体进入引起的氧化应激。海藻化合物不是单一的疾病控制机制，而是引发一系列反应，激活植物防御，提供针对植物病原真菌的多重抵抗和保护。这极大地促进了植物生长的良性环境，以经济且可持续的方式积极影响植物产品的营养状况和产量。