Host-specific plant signal and G-protein activator, mastoparan, trigger differentiation of zoospores of the phytopathogenic oomycete Aphanomyces cochlioides
Host-specific plant signal and G-protein activator, mastoparan, trigger differentiation of zoospores of the phytopathogenic oomycete Aphanomyces cochlioides
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DOI：
10.1023/a:1026114731718
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发表时间：
2003-08-01
期刊：
影响因子：
4.9
通讯作者：
Tahara, S
中科院分区：
文献类型：
--
作者：
Islam, MT;Ito, T;Tahara, S
我们发现，梯度的主机特定的引诱剂，cochliophilin A（5-羟基-6，7-亚甲基二氧基黄酮）从菠菜的根分离触发包囊随后萌发的游动孢子的隐孢子虫cochlioides在浓度小于微摩尔的顺序。该化合物在培养基中浓度高达10（-6）M时不影响该植物病原体的生长和繁殖。我们还观察到异三聚体G蛋白激活剂mastoparan可抑制游动孢子的运动，然后显著影响包囊形成，随后60 - 80%的包囊萌发。同时应用cochliophilin A和mastoparan表现出更强的包囊化，随后100%的包囊萌发。此外，我们已经观察到，干扰磷脂酶C活性（新霉素）和Ca 2+内流/释放（EGTA和洛哌丁胺）的化学物质抑制cochliophilin A或mastoparan诱导的包囊形成和萌发。提示G蛋白介导的信号转导机制可能参与了A. Cochlioides游动孢子这是第一个报告的分化卵菌游动孢子启动的主机特定的植物信号或G蛋白激活剂。
We found that the gradient of a host-specific attractant, cochliophilin A (5-hydroxy-6,7-methylenedioxyflavone) isolated from the roots of spinach triggered encystment followed by germination of zoospores of Aphanomyces cochlioides at a concentration less than micromolar order. This compound did not affect the growth and reproduction of this phytopathogen up to 10(-6) M concentration in the culture medium. We also observed that mastoparan, an activator of heterotrimeric G-protein could inhibit the motility of zoospores and then strikingly effect encystment followed by 60 - 80% germination of cysts. Concomitant application of cochliophilin A and mastoparan showed stronger encystment followed by 100% germination of cysts. In addition, we have observed that chemicals interfering with phospholipase C activity ( neomycin) and Ca2+ influx/release ( EGTA and loperamide) suppress cochliophilin A or mastoparan induced encystment and germination. These results suggest that G-protein mediated signal transduction mechanism may be involved in the differentiation of the A. cochlioides zoospores. This is the first report on the differentiation of oomycete zoospores initiated by a host-specific plant signal or a G-protein activator.