Centre d'Agrobiotechnologie et Bioingénierie, Unité de Recherche Labellisée CNRST (Centre AgroBiotech-URL-CNRST-05), Faculté des Sciences et Techniques Marrakech, Université Cadi Ayyad, Marrakech 40000, Morocco.
Université Clermont Auvergne, Clermont Auvergne INP, CNRS, Institut Pascal, 63000 Clermont-Ferrand, France.
Mar Drugs. 2022 Jan 20;20(2):88. doi: 10.3390/md20020088.
In many African countries, the Bayoud is a common disease spread involving the fungus f. sp. (Foa). The induction of plant natural defenses through the use of seaweed polysaccharides to help plants against pathogens is currently a biological and ecological approach that is gaining more and more importance. In the present study, we used alginate, a natural polysaccharide extracted from a brown algae , to activate date palm defenses, which involve phenylalanine ammonia-lyase (PAL), a key enzyme of phenylpropanoid metabolism. The results obtained showed that at low concentration (1 g·L), alginate stimulated PAL activity in date palm roots 5 times more compared to the negative control (water-treated) after 24 h following treatment and 2.5 times more compared to the laminarin used as a positive stimulator of plant natural defenses (positive control of induction). Using qRT-PCR, the expression of a selection of genes involved in three different levels of defense mechanisms known to be involved in response to biotic stresses were investigated. The results showed that, generally, the PAL gene tested and the genes encoding enzymes involved in early oxidative events (SOD and LOX) were overexpressed in the alginate-treated plants compared to their levels in the positive and negative controls. POD and PR protein genes selected encoding -(1,3)-glucanases and chitinases in this study did not show any significant difference between treatments; suggesting that other genes encoding POD and PR proteins that were not selected may be involved. After 17 weeks following the inoculation of the plants with the pathogen Foa, treatment with alginate reduced the mortality rate by up to 80% compared to the rate in control plants (non-elicited) and plants pretreated with laminarin, which agrees with the induction of defense gene expression and the stimulation of natural defenses in date palm with alginate after 24 h. These results open promising prospects for the use of alginate in agriculture as an inducer that triggers immunity of plants against telluric pathogens in general and of date palm against f. sp. in particular.
在许多非洲国家，贝尤德病是一种常见的真菌病，涉及真菌 f. sp. （Foa）。目前，利用海藻多糖诱导植物天然防御以帮助植物抵抗病原体是一种越来越重要的生物和生态方法。在本研究中，我们使用褐藻提取的天然多糖藻酸盐激活了海枣防御系统，其中涉及苯丙氨酸解氨酶（PAL），这是苯丙烷代谢的关键酶。结果表明，在低浓度（1 g·L）下，与阴性对照（水处理）相比，藻酸盐在处理后 24 小时刺激海枣根系中 PAL 活性增加了 5 倍，与作为植物天然防御正向刺激物的昆布多糖相比增加了 2.5 倍（正向诱导物）。使用 qRT-PCR 检测了参与三种不同防御机制的选择基因的表达，这些防御机制已知参与对生物胁迫的反应。结果表明，一般来说，与阳性和阴性对照相比，在藻酸盐处理的植物中，测试的 PAL 基因和编码参与早期氧化事件的酶的基因（SOD 和 LOX）过度表达。在本研究中选择的编码 -(1,3)-葡聚糖酶和几丁质酶的 POD 和 PR 蛋白基因在处理之间没有显示出任何显著差异；这表明，未被选择的编码 POD 和 PR 蛋白的其他基因可能参与其中。在接种 Foa 病原体 17 周后，与未处理的对照植物（未诱导）和用昆布多糖预处理的植物相比，用藻酸盐处理使死亡率降低了 80%，这与防御基因表达的诱导以及在 24 小时后藻酸盐对海枣天然防御的刺激一致。这些结果为在农业中使用藻酸盐作为诱导剂来触发植物对土壤病原体的免疫力开辟了广阔的前景，特别是对海枣对 f. sp. 的免疫力。
