蜜环菌侵染后猪苓菌核防御结构的发生及功能

蜜环菌通过猪苓菌核表皮侵染菌核时,菌核表皮下层的菌丝具特异的拮抗反应,如细胞中有结晶颗粒出现,厚壁菌丝形成,部分薄壁菌丝有质壁分离现象。蜜环菌的侵染诱导了菌核防御结构的发生:离侵染点一定距离的部位出现由少量木质化菌丝和厚壁菌丝形成的疏松带状;蜜环菌侵入后,上述菌丝增多并紧密排列形成菌核的初级隔离腔,入侵的蜜环菌和部分菌核被隔离在腔中;在初级隔离腔形成的同时,外围的次级隔离腔开始发育。蜜环菌菌索和皮层菌丝分枝可突破初、次级隔离腔的壁,再以菌索产生的侵染带侵染菌核较外部的最后防线即三级隔离腔。本文较系统的阐述了蜜环菌侵染后菌核各防御结构的发生特点及功能。     

蜜环菌侵染后猪苓菌核防御结构的发生及功能

蜜环菌通过猪苓菌核表皮侵染菌核时,菌核表皮下层的菌丝具特异的拮抗反应,如细胞中有结晶颗粒出现,厚壁菌丝形成,部分薄壁菌丝有质壁分离现象。蜜环菌的侵染诱导了菌核防御结构的发生：离侵染点一定距离的部位出现由少量木质化菌丝和厚壁菌丝形成的疏松带状;蜜环菌侵入后,上述菌丝增多并紧密排列形成菌核的初级隔离腔,入侵的蜜环菌和部分菌核被隔离在腔中;在初级隔离腔形成的同时,外围的次级隔离腔开始发育。蜜环菌环菌和部     

猪苓与蜜环菌高亲和性组合的筛选

猪苓与蜜环菌共生亲和性是猪苓人工栽培成功的关键因素。为获得猪苓与蜜环菌的高亲和性组合,本文采用了5株猪苓菌株与4株蜜环菌菌株进行筛选。通过将猪苓菌株与蜜环菌菌株共培养,比较不同组合的生长速度、拮抗线形成情况,以及两种菌丝生长过程中形态学变化等指标,结果发现组合GU-06&AM-08生长速度最快,为3.36mm/d。GU-06和GU-07-2菌株与每株蜜环菌共培养均可产生拮抗线,共培养28d后,产生拮抗的猪苓菌丝分枝较多,可以看到菌丝束。被蜜环菌菌索侵染的猪苓菌核,切面可以明显观察到侵入猪苓菌核中的蜜环菌菌索,侵染到猪苓菌核中的蜜环菌菌索分枝较多,中空,表皮细胞细长。发生侵染现象的组合有7组：GU-04与AM-06;GU-06与AM-06,AM-08,AM-13;GU-07-2与AM-06,AM-08;GU-15与AM-06,其中以GU-06与AM-06,AM-13两组组合侵染最严重,其余组合没有发现侵染现象。综合以上共生筛选指标获得GU-06&AM-08、GU-06&AM-06、GU-07-2&AM-08以及GU-06&AM-13 4组高亲和性的组合。     

蜜环菌激发子诱导猪苓细胞产生活性氧及其相关酶的变化*

研究了蜜环菌激发子处理猪苓细胞后活性氧产生及相关酶的变化。结果表明 :蜜环菌激发子分别处理猪苓菌丝和菌核后 ,都能引起活性氧迸发 ,且出现两个迸发高峰 ,高峰期分别在加入激发子后约 1 0min和 90min。与此同时 ,猪苓菌丝酶活性也发生相应变化 ,超氧化物岐化酶 (SOD)、过氧化物酶 (POD)活性下降 ,过氧化氢酶 (CAT)活性没有变化 ,而苯丙氨酸解氨酶 (PAL)活性出现先下降后上升的趋势。     

猪苓、伴生菌及蜜环菌共培养的形态学研究*

本文对猪苓、伴生菌及蜜环菌两两共培养及三者共培养进行了宏观形态观察及细胞学水平上的研究。结果表明,猪苓与伴生菌共培养时,在二者之间形成一致密拮抗线,猪苓菌落表面菌丝分化产生大量菌丝束;猪苓与蜜环菌共培养时,猪苓能阻止蜜环菌菌索对其自身的进一步侵袭,互作区中的双方菌丝及菌索均停止生长;蜜环菌与伴生菌共培养时,蜜环菌能穿透整个伴生菌菌落,在伴生菌菌落下方产生大量分枝;三者共培养后,猪苓对蜜环菌的防御能力有所下降,伴生菌对蜜环菌的耐受力有所提高,蜜环菌产生的新分枝均向伴生菌一侧生长,猪苓与伴生菌之间并不形成致密拮抗线,只可见双方菌丝的白色交融区。 猪苓与伴生菌均能在蜜环菌菌索皮层上形成侵入位点。     

猪苓、伴生菌及蜜环菌共培养的形态学研究

本文对猪苓、伴生菌及蜜环菌两两共培养及三者共培养进行了宏观形态观察及细胞学水平上的研究。结果表明,猪苓与伴生菌共培养时,在二者之间形成一致密拮抗线,猪苓菌落表面菌丝分化产生大量菌丝束;猪苓与蜜环菌共培养时,猪苓能阻止蜜环菌菌索对其自身的进一步侵袭,互作区中的双方菌丝及菌索均停止生长;蜜环菌与伴生菌共培养时,蜜环菌能穿透整个伴生菌菌落,在伴生菌菌落下方产生大量分枝;三者共培养后,猪苓对蜜环菌的防御能力有所下降,伴生菌对蜜环菌的耐受力有所提高,蜜环菌产生的新分枝均向伴生菌一侧生长,猪苓与伴生菌之间并不形成致密拮抗线,只可见双方菌丝的白色交融区。 猪苓与伴生菌均能在蜜环菌菌索皮层上形成侵入位点。     

猪苓、伴生菌及蜜环菌共培养的形态学研究

本文对猪苓、伴生菌及蜜环菌两两共培养及三者共培养进行了宏观形态观察及细胞学水平上的研究。结果表明,猪苓与伴生菌共培养时,在二者之间形成一致密拮抗线,猪苓菌落表面菌丝分化产生大量菌丝束;猪苓与蜜环菌共培养时,猪苓能阻止蜜环菌菌索对其自身的进一步侵袭,互作区中的双方菌丝及菌索均停止生长;蜜环菌与伴生菌共培养时,蜜环菌能穿透整个伴生菌菌落,在伴生菌菌落下方产生大量分枝;三者共培养后,猪苓对蜜环菌的防御能力有所下降,伴生菌对蜜环菌的耐受力有所提高,蜜环菌产生的新分枝均向伴生菌一侧生长,猪苓与伴生菌之间并不形成致密拮抗线,只可见双方菌丝的白色交融区。猪苓与伴生菌均能在蜜环茵菌索皮层上形成侵入位点。     

天麻消化紫萁小菇及蜜环菌过程中细胞超微结构变化的研究

本文对天麻种子消化入侵的紫萁小菇菌丝及营养繁殖茎消化蜜环菌过程中,细胞超微结构的变化进行了研究。观察结果表明:紫萁小菇侵入种胚后,染菌胚细胞的细胞器逐渐消失,其细胞质产生囊状体起消化菌丝的作用,存在于胚细胞中的紫萁小菇菌丝有脱壁或失去细胞质成为空腔等变化;种子萌发形成的原球茎消化紫萁小菇的方式同胚萌发阶段类同。蜜环菌侵入原球茎分化的营养繁殖茎后,皮层细胞产生消化酶类颗粒或囊状体包围并分解蜜环菌菌丝;被皮层细胞消化的菌丝残物或部分菌丝进入皮层内面的大型细胞,此时大型细胞的代谢功能显著增强,该细胞中的各种水解酶颗粒及液泡等完成对菌体物质的最终同化。紫萁小菇及蜜环菌先后在天麻有性繁殖和无性繁殖阶段侵染供给其营养,但菌丝被消化过程中的细胞形态变化、被消化方式不完全一致。     

天麻种子／原球茎和营养繁殖茎被菌根真菌定殖后的细胞分化

天麻（Gastrodia elata Bl.)种子可与紫萁小菇（Mycena osmundicola Lange),兰小菇（M.orchidicola Fan et Guo)等一类小菇属真菌共生萌发形成原球茎。侵入种皮的菌丝集结在柄状细胞外周的胚柄残迹中,首先侵入胚的柄状细胞,然后自柄状细胞侵入其他原胚细胞。原胚细胞发生功能分化,形成菌丝结细胞和消化细胞,初被菌丝定殖的原胚细胞具有消化菌丝的功能,随后,部分原胚细胞逐渐被菌丝充满,充育成菌丝结细胞。菌丝由菌丝结细胞进一步侵入消化细胞后最终被消化。由原球茎分化形成的营养繁殖茎（以下简称营繁茎）进一步被蜜环菌（Armilariella mellea(Vahl.Fr.)Karst.)定植,蜜环菌与紫箕小菇的菌丝同时存在于营繁茎中,但两菌相遇时都停止蔓延,互不交错侵染。     

猪苓糖苷水解酶家族基因及其差异表达

猪苓与蜜环菌建立共生关系时,猪苓菌丝会反侵染并消解蜜环菌菌索,以获取营养物质,糖苷水解酶是参与这一过程的主要酶类之一。本研究从猪苓转录数据库中获得糖苷水解酶家族基因42类、309个;其编码的糖苷水解酶蛋白含各类结构域344个,以糖苷水解酶结构域glyco＿hydro为主,共计35类173个。对猪苓糖苷水解酶进行的gene ontology (GO)功能注释结果表明,这些蛋白参与的生物学过程以物质代谢及分解过程为主,特别是多糖等大分子物质代谢;181个猪苓糖苷水解酶具有水解酶活性,这些水解酶活性呈多样性分布。与未被蜜环菌侵染的猪苓部位相比,43个糖苷水解酶基因在蜜环菌侵染的菌核部位中差异表达,编码包括glyco＿hydro＿48、cellulase和polysacc＿deac＿1等功能结构域,可能发挥水解几丁质、纤维素酶活性及免疫调节等活性,这为猪苓与蜜环菌互作关系的研究提供了候选基因及蛋白。     

Nutrient Source of Sclerotia of Grifola umbellata and Its Relationship to Armillaria mellea

Ways nutrient-uptake of sclerotia of Grifola umbellata and the relationship between G. umbellata and Armillaria mellea were studied. At the primary stage of sclerotia of G. umbellate infected by A. mellea, the hyphae of G. umbellata could obtain nutrients by invading the one- to three-layer-cells of A. mellea cortex which existed in the sclerotia of G. umbellata, ar late stage of A. mellea infection, the nutrient source of sclerotia of G. umbellata mainly depended on its hyphae, adhering on the intercellular space of A. mellea, to suck the metabolic products of A. mellea. After being nourished the hyphae of sclerotia of G. umbellata outside of the rhizomorph of A. mellea began to reproduce, as their nuclear divisions were well observed. The results suggested that the mutual assimilation between G. umbellata and A. meIlea could be defined as a form of special Symbiotic relation.     

Cytological Studies on the Process of Armillaria Mellea Infection Through the Sclerotia of Grifola Umbellata

Adhering to the sclerotium of Grifola umbellata, Armillaria mellea could invade the sclerotium in a manner of rhizomorph without capsule, after which the sclerotium formed a deep coloured stereoscopic septate cavity outside of the rhizomorph. At the early stage of infection, segmentation was visualized either in the cortex or the apex of A. mellea rhizomorph to form a new rhizomorph which penetrated another parts of G. umbellata sclerotium. At the late stage of infection, the cortical hyphae of A. mellea rhizomorph produced a branch to invade the wall of the septate cavity of G. umbellata sclerotium and, in a manner of hyphae, it could further form new rhizomorph after its penetration through that wall. An alternate way of expanding A. mellea infection in sclerotium was to form a invading band which was composed of a few rolls of round ceils derived from cortical hyphae of A. mellea rhizomorph. The band could invade sclerotia to a farther distance and then could connect with each other.     

猪苓菌核结晶及厚壁细胞的起源与发育

猪苓菌核的含晶细胞发生于菌丝中间或顶端,该细胞具有体积大、细胞质丰富等特点;结晶是由细胞质中的微小颗粒沉积于液泡中逐渐发育而成,液泡周围常有数量较多的线粒体分布,结晶发育至一定大小时细胞壁破裂释放出结晶,单个结晶在菌核中可聚集成大的棱状晶体。厚壁细胞产生于菌丝中间,与两端细胞以横隔膜相隔,细胞质收缩的同时胞壁加厚,厚壁细胞发育至仅留很小胞腔或完全被加厚物质充满时,可与相邻菌丝细胞分离;猪苓菌核厚壁细胞与有些真菌无性厚壁孢子的形成类同,但其大小不等在5～30μm之间。     

猪苓菌丝形成菌核伴生菌的发现及应用

在野生猪苓(Grifola umbellata (Pers.) Pilát)菌核生长穴中首次分离到猪苓菌丝形成菌核所必需的伴生菌(Grifola sp.).实验证明:纯培养的猪苓菌丝不能形成菌核,但其与伴生菌共培养,无论在实验室培养基上或用树棒栽培,猪苓菌核形成很快且发育正常;伴生菌是猪苓菌丝形成菌核的关键生物因子.另外,伴生菌菌丝和猪苓菌菌丝二者形态差别较大,前者多为细长的薄壁菌丝,后者多为细胞直径较大的薄壁和厚壁菌丝.     

猪苓菌核结构性质的研究

利用光学显微镜和电子显微镜对猪苓菌核的结构及其发育进行了研究。组成猪苓菌核的菌丝与平板培养或发酵培养的猪苓菌丝比较,具有多分枝、融合频率高、菌丝形态不规则等特点。猪苓菌核表现了高度的结构分化,有表皮、表皮下层、疏松菌丝层和结构菌丝之分,结构菌丝是组成菌核的主要成分,疏松菌丝层类似一般菌核的髓,但大小、位置在菌核中变化较大。菌核的个体繁殖是由母体菌核的一束或几柬菌丝突破表皮而萌发产生新的菌核;较系统的观察了猪苓菌核细胞分裂及其菌丝内部结构的变化。     

Study on Ultrastructure and Localization of Acid Phosphatase of Gastrodia elata Cortical Cells in Their Digestive Process of Armillaria mellea

In order to study the mechanism of the digestive process of Armillaria mellea in Castrodia data, electron microscopy and cytochemical method for determination of acid phosphatase activity was employed. The provacuoles were formed by means of expanded or convoluted ER under the stimulation of cortical cells and large cells of Gastrodia data by Armillaria mellea. A product of acid phosphatase (lead phosphate deposits) occured on the tonoplast. The papillae were produced in the cell wall of cortex in Gastrodia data when Armillaria mellea penetrated into its cortex. Our results showed that the enzyme was not released from cell of Armillaria mellea. A number of small vacuoles in the cortical cells disappeared. At the same time, lead phosphate deposits on the Armillaria mellea hyphae wall were observed and than Armillaria mellea hyphae wall was going to be digested, and the hyphae lost their structure. The activity of Armillaria mellea hyphae was not observed in the large cell of Gastrodia data. A great deal of small vacuoles and mitochondria were produced, at the same time the renewable nuclei and nuclolar vacuoles etc. appeared in the large cells of Gastrodia data under the stimulation of Armillaria mellea.     

Morphological characteristics of sclerotia formed from hyphae of <Emphasis Type="Italic">Grifola umbellata</Emphasis> under artificial conditions

The morphological characteristics of sclerotia were induced in cultures of the fungus Grifola umbellata by introducing an unidentified companion fungus were studied by light microscope, scanning and transmission electron microscope (SEM and TEM). Light microscope and SEM investigations of developing sclerotia revealed that aerial mycelial hyphae diminished with age, and mature sclerotia had two tissue layers, the rind and medulla. The medulla was comprised of thin and thick-walled hyphae of varying diameter. The thick-walled cells always formed below the hyphal tips. Retraction of the cytoplasm was accompanied by the thickening of cell wall. There were crystalline initials in the newly formed sclerotium. Crystalline initials were always formed in the tip of medullary hyphae and were not of regular shape. A series of changes occurred in the cells in which the crystalline initials would be formed, such as enlargement of size, formation of one or several large vacuoles. Crystalline initials developed via amorphous materials in the cytoplasm deposited in the vacuoles. At last crystalline initials was released by degradation of the cell wall.