{"title":"天麻与真菌共生种子萌发过程中的超微结构变化,重点是真菌定殖区。","authors":"Yuan-Yuan Li, Shun-Xing Guo, Yung-I Lee","doi":"10.1186/s40529-019-0280-z","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>Gastrodia elata is a fully mycoheterotrophic orchid and has long been used in traditional Chinese medicine. The life cycle of G. elata requires an association with two different fungi-Mycena for seed germination and Armillaria for tuber growth. The association with Armillaria is representative of the phytophagous type of orchid mycorrhiza: the intracellular hyphae are lysed without forming condensed pelotons. However, whether the association with Mycena during seed germination belongs to the same type of orchid mycorrhiza is unknown.</p><p><strong>Results: </strong>Histological and ultrastructural studies revealed several notable features in different developmental stages. First, a thickened cell wall with papillae-like structures appeared during fungal penetration in the suspensor end cell, epidermal cells and cortical cells of germinating embryos. In addition, the formation of two distinctive cell types in the colonized region of a protocorm (i.e., the passage canal cell filled with actively growing fungal hyphae) can be observed in the epidermal cell, and the distinctive digestion cell with a dense cytoplasm appears in the cortex. Finally, within the digestion cell, numerous electron-dense tubules form a radial system and attach to degrading fungal hyphae. The fungal hyphae appear to be digested through endocytosis.</p><p><strong>Conclusions: </strong>The present study provides important structural evidence for the phytophagous type of orchid mycorrhiza in the symbiotic germination of G. elata with Mycena. This case demonstrates a particular nutrient transfer network between G. elata and its litter-decaying fungal partner.</p>","PeriodicalId":48844,"journal":{"name":"Botanical Studies","volume":null,"pages":null},"PeriodicalIF":4.1000,"publicationDate":"2020-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7016048/pdf/","citationCount":"0","resultStr":"{\"title\":\"Ultrastructural changes during the symbiotic seed germination of Gastrodia elata with fungi, with emphasis on the fungal colonization region.\",\"authors\":\"Yuan-Yuan Li, Shun-Xing Guo, Yung-I Lee\",\"doi\":\"10.1186/s40529-019-0280-z\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><strong>Background: </strong>Gastrodia elata is a fully mycoheterotrophic orchid and has long been used in traditional Chinese medicine. The life cycle of G. elata requires an association with two different fungi-Mycena for seed germination and Armillaria for tuber growth. The association with Armillaria is representative of the phytophagous type of orchid mycorrhiza: the intracellular hyphae are lysed without forming condensed pelotons. However, whether the association with Mycena during seed germination belongs to the same type of orchid mycorrhiza is unknown.</p><p><strong>Results: </strong>Histological and ultrastructural studies revealed several notable features in different developmental stages. First, a thickened cell wall with papillae-like structures appeared during fungal penetration in the suspensor end cell, epidermal cells and cortical cells of germinating embryos. In addition, the formation of two distinctive cell types in the colonized region of a protocorm (i.e., the passage canal cell filled with actively growing fungal hyphae) can be observed in the epidermal cell, and the distinctive digestion cell with a dense cytoplasm appears in the cortex. Finally, within the digestion cell, numerous electron-dense tubules form a radial system and attach to degrading fungal hyphae. The fungal hyphae appear to be digested through endocytosis.</p><p><strong>Conclusions: </strong>The present study provides important structural evidence for the phytophagous type of orchid mycorrhiza in the symbiotic germination of G. elata with Mycena. This case demonstrates a particular nutrient transfer network between G. elata and its litter-decaying fungal partner.</p>\",\"PeriodicalId\":48844,\"journal\":{\"name\":\"Botanical Studies\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":4.1000,\"publicationDate\":\"2020-02-12\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7016048/pdf/\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Botanical Studies\",\"FirstCategoryId\":\"99\",\"ListUrlMain\":\"https://doi.org/10.1186/s40529-019-0280-z\",\"RegionNum\":3,\"RegionCategory\":\"生物学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"PLANT SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Botanical Studies","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1186/s40529-019-0280-z","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"PLANT SCIENCES","Score":null,"Total":0}
引用次数: 0
摘要
背景:天麻(Gastrodia elata)是一种全霉菌兰科植物,长期以来一直被用于传统中药中。天麻的生命周期需要与两种不同的真菌结合--Mycena(用于种子发芽)和Armillaria(用于块茎生长)。与臂孢菌的结合是兰花菌根中植物吞噬型菌根的代表:胞内菌丝被裂解,而不形成凝结的颗粒。然而,在种子萌发过程中与霉菌的结合是否属于兰花菌根的同一类型尚不清楚:组织学和超微结构研究显示了不同发育阶段的几个显著特点。首先,在真菌穿透发芽胚的悬丝末端细胞、表皮细胞和皮层细胞时,细胞壁增厚并出现乳头状结构。此外,在原球茎的定殖区(即充满活跃生长的真菌菌丝的通道细胞),可以观察到表皮细胞中形成了两种独特的细胞类型,而在皮层细胞中则出现了具有致密细胞质的独特消化细胞。最后,在消化细胞内,许多电子致密小管形成一个放射状系统,并附着在降解的真菌菌丝上。真菌菌丝似乎是通过内吞作用被消化的:结论:本研究提供了重要的结构证据,证明兰花菌根的植食性类型存在于 G. elata 与真菌的共生发芽过程中。本研究为兰花菌根的植食性共生萌发提供了重要的结构证据,证明了兰花菌根与其垃圾腐生真菌伙伴之间的特殊营养传递网络。
Ultrastructural changes during the symbiotic seed germination of Gastrodia elata with fungi, with emphasis on the fungal colonization region.
Background: Gastrodia elata is a fully mycoheterotrophic orchid and has long been used in traditional Chinese medicine. The life cycle of G. elata requires an association with two different fungi-Mycena for seed germination and Armillaria for tuber growth. The association with Armillaria is representative of the phytophagous type of orchid mycorrhiza: the intracellular hyphae are lysed without forming condensed pelotons. However, whether the association with Mycena during seed germination belongs to the same type of orchid mycorrhiza is unknown.
Results: Histological and ultrastructural studies revealed several notable features in different developmental stages. First, a thickened cell wall with papillae-like structures appeared during fungal penetration in the suspensor end cell, epidermal cells and cortical cells of germinating embryos. In addition, the formation of two distinctive cell types in the colonized region of a protocorm (i.e., the passage canal cell filled with actively growing fungal hyphae) can be observed in the epidermal cell, and the distinctive digestion cell with a dense cytoplasm appears in the cortex. Finally, within the digestion cell, numerous electron-dense tubules form a radial system and attach to degrading fungal hyphae. The fungal hyphae appear to be digested through endocytosis.
Conclusions: The present study provides important structural evidence for the phytophagous type of orchid mycorrhiza in the symbiotic germination of G. elata with Mycena. This case demonstrates a particular nutrient transfer network between G. elata and its litter-decaying fungal partner.
期刊介绍:
Botanical Studies is an open access journal that encompasses all aspects of botany, including but not limited to taxonomy, morphology, development, genetics, evolution, reproduction, systematics, and biodiversity of all plant groups, algae, and fungi. The journal is affiliated with the Institute of Plant and Microbial Biology, Academia Sinica, Taiwan.