Peptide uptake in the ectomycorrhizal fungus Hebeloma cylindrosporum:: characterization of two di- and tripeptide transporters (HcPTR2A and B)
Peptide uptake in the ectomycorrhizal fungus Hebeloma cylindrosporum:: characterization of two di- and tripeptide transporters (HcPTR2A and B)
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DOI：
10.1111/j.1469-8137.2006.01672.x
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发表时间：
2006-01-01
期刊：
影响因子：
9.4
通讯作者：
Wipf, D
中科院分区：
文献类型：
--
作者：
Benjdia, M;Rikirsch, E;Wipf, D
氮素有效性低对植物生长的限制是以外生菌根植物为主的生态系统的一个特征。外生菌根真菌在植物氮素营养中起着关键作用，它使其宿主植物能够获得死亡植物和动物材料的分解产物。外生菌根植物能够补偿森林生态系统中无机氮的低有效性。本研究分析了外生菌根真菌柱孢Hebeloma cylindrosporum吸收多肽的能力及其运输机制。柱孢菌菌丝体能够吸收二肽和三肽并将其用作唯一的N源。利用酵母功能互补法分离了两个肽转运蛋白（HcPTR 2A和B）。结果表明，HcPTR2A和HcPTR2B均参与了氮素限制条件下多肽的高效吸收，而HcPTR2A和HcPTR2B均为组成型表达。
Constraints on plant growth imposed by low availability of nitrogen are a characteristic feature of ecosystems dominated by ectomycorrhizal plants. Ectomycorrhizal fungi play a key role in the N nutrition of plants, allowing their host plants to access decomposition products of dead plant and animal materials. Ectomycorrhizal plants are thus able to compensate for the low availability of inorganic N in forest ecosystems.The capacity to take up peptides, as well as the transport mechanisms involved, were analysed in the ectomycorrhizal fungus Hebeloma cylindrosporum.The present study demonstrated that H. cylindrosporum mycelium was able to take up di- and tripeptides and use them as sole N source. Two peptide transporters (HcPTR2A and B) were isolated by yeast functional complementation using an H. cylindrosporum cDNA library, and were shown to mediate dipeptide uptake.Uptake capacities and expression regulation of both genes were analysed, indicating that HcPTR2A was involved in the high-efficiency peptide uptake under conditions of limited N availability, whereas HcPTR2B was expressed constitutively.