Behaviour of zoospores and zoospore cysts in relation to root infection by Pythium aphanidermatum.
Behaviour of zoospores and zoospore cysts in relation to root infection by Pythium aphanidermatum.
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DOI：
10.1111/j.1469-8137.1991.tb04910.x
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发表时间：
1991-02
期刊：
影响因子：
9.4
通讯作者：
S. Jones;S. Donaldson;J. Deacon
中科院分区：
文献类型：
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作者：
S. Jones;S. Donaldson;J. Deacon
发明内容当小麦、水芹或番茄的根被置于Pythiumaphanidermatum（Edson）Fitzp的游动孢子的悬浮液中时，通过视频显微镜研究了包括游动孢子趋动、包囊形成、包囊萌发和芽管定向的预穿透序列。该序列也在体外进行了研究，以确定负责的因素。几种氨基酸，糖或挥发性化合物引起的序列的一个或多个阶段，但只有谷氨酸和天冬氨酸引起的所有阶段，因此可以解释所观察到的行为根。根表面粘液的多糖醛酸盐也可能需要孢子的包囊化和定向，因为芽管从排水液泡前位置附近的固定点出现向根。然而，相同的模式游动孢子的积累和encystment未处理的根和根包裹在藻酸盐凝胶表明，无论是多糖醛酸酯，也没有特定的糖残基的根粘液引起局部encystment根。在此基础上，提出了一种“最简单情况”的根部预侵彻序列模型。
summary The Pre-Penetration Sequence Involving Zoospore Taxis, encystment, Cyst Germination And Germ-Tube Orientation Was Studied By Video Microscopy When Roots Of Wheat, Cress or Tomato Were Placed In Suspensions of Zoospores of Pythium aphanidermatum (Edson) Fitzp. The Sequence Was Also Studied In Vitro, to identify the responsible Factors. Several amino acids, sugars or volatile compounds elicited one of more stages of the sequence, but only glutamic acid and aspartic acid elicited all stages and thus could account for the observed behaviour on roots. Polyuronates of root surface slime also may be needed for encystment and orientation of Spores, because germ-tubes emerged towards roots from a fixed point near the former position of the water-expulsion vacuole. However, identical patterns of zoospore accumulation and encystment on untreated roots and roots encased in alginate gel indicated that neither polyuronates nor Specific sugar residues of root slime caused localized encystment on roots. Based on these results, a ‘simplest case’ model of the pre-penetration sequence on roots is proposed.