摘要
紫萁小茹侵入天麻幼苗以后，在根的皮层细胞内形成两类不同的染菌细胞：外部１－２层是包含紧密缠绕的菌丝团的细胞，简称为菌丝结细胞；内部一层细胞形态较大，只含少量菌丝，称为真菌消化细胞。酸性磷酸酶的细胞化学研究表明，菌丝结细胞内酶活性很低，只在少数老的菌丝内部具有酸性磷酸酶活性，未见植物细胞释放水解酶，因而菌丝结细胞内少量菌丝的溶解应属于自溶。
A cytochemical study has been made to examine the activity of acid β-glyceropho-sphatase in the mycorrhizal cells of the seedling of Gastrodia elata B1. using thin sectioning technique in which sections were embedded in glycol mathacrylate (GMA). After the seedling was invaded by the hyphae of Mycena osmundicola Lange, two different kin- ds of infected cells were formed in its root cortex: the outer 1-2 cell layers namely the hyphae-containing cells (or host cells) contained many coiled hyphae pelotons; the inner comparativly large cell layer or fungus-digesting cells contained a few straight hyphae. Localization of acid phosphatase in hyphae-containing cells showed that only a few senescent hyphae retained the enzyme activity and the plant cells did not release hydrolytic enzyme. So it is considered that the hyphal lysis in hyphae-containing cell may be due to autolysis. In contrast, higher acid phosphatase activity was visualized in many vesicles and small vacuoles of the fungus-digesting cells. When a hypha entered a fungus-digesting cell through a hyphae-containing cell, a number of enzyme granules (i. e. enzyme-containing vesicles) gathered around it. Later on the enzyme granules expanded gradually and became small enzyme vacuoles of 1. 6-2. 0 μm in diameter. Still later the small enzyme vacuoles fused with each other to form a large vacuole in which a part of an invading hypha was enclosed and gradually digested by hydrolytic enzymes. Finally,the digesting vacuole changed into a residual body containing some metabolic waste. The above results suggest that fungus-digesting cells can actively release hydrolytic enzymes by lysosomal vesicles to digest the invading hyphae, but such function is not present in the hyphae-containing cells,the role of which may be attributed to attracting and controling the invading hyphae.
基金
国家自然科学基金资助项目
关键词
天麻
兰科
菌根
酸性磷酸酶
真菌
Gastrodia elata
Mycena osmundicola
Orchid mycorrhiza
Phosphatase
Vacuole
