天麻吸收蜜环菌营养机制的细胞学研究

天麻(Gastrodia elata BI.)地下块茎皮层内具三种染菌细胞:通道细胞、寄主细胞和消化细胞。超微结构的研究表明,通道细胞被真菌所破坏,寄主细胞与真菌保持共生关系,而消化细胞能反寄生于真菌并从真菌摄取营养。消化细胞首先释放溶酶体小泡消化真菌,然后通过内吞管和内吞泡吸收菌丝细胞质降解后渗漏的可溶性有机大分子物质,后期通过消化泡进一步吞噬和消化不溶性菌丝细胞壁物质。

A CYTOLOGICAL STUDY ON THE NUTRIENT-UPTAKE MECHANISM OF A SAPROPHYTIC ORCHID GASTRODIA ELATA

There are three type cells infected by the mycorrhizal fungus, Armillaria mellea (Vahl ex Fr.) Karst in the tube cortex of Gastrodia elata Bl. , namely the passage cells, host cells and digesting cells. Ultrastructural study demonstrated that the passage cells were distroyed by the hyphae, the host cells kept symbiotic with the hyphae, but the digesting cells could become inversely parasitic on the hyphae from which nutrient were being uptaken. The detail process of the digesting cells obtaining nutrient'from the fungus is described as follows: Firstly the digesting cells began to attack the invading hyphae by releasing numerious electron-transparent vesicles of lysosomal property, secondly they took up the soluble organic material leaked out from the digested hyphae by forming many electron-dense endocytic tubes and vesicles, and finally they endocytosed and hydrolysed the insoluble hyphal walls by forming large digesting vacuole in which a piece of hyphal wall was completly enveloped.