沪农灵芝一号生长过程中子实体各部位糖醇和海藻糖积累及其代谢酶的表达变化

Change of polyol and trehalose content and expression of their related metabolism enzymes in Ganoderma lingzhi SH during fruiting body growth

食用菌子实体通常会在生长过程中积累较高含量的糖醇及海藻糖,这些碳水化合物的积累能够促进食用菌的生长,而在灵芝中的同类研究较少,本研究通过高效阴离子-脉冲安培法对沪农灵芝一号子实体发育过程中不同部位的糖类成分的含量变化进行分析,发现灵芝子实体中主要的可溶性糖类成分是阿拉伯糖醇、甘露醇和海藻糖,甘露醇在子实体成熟时的菌盖中的含量达到最高值,阿拉伯糖醇在产孢子期的子实体中含量较高,两种糖醇的含量呈现相反的变化趋势,一种糖醇积累的同时会消耗利用另一种糖醇,而海藻糖在灵芝子实体的整个生长过程中含量处于较低水平,仅在子实体初期的菌基部位检测到较高的含量;同时通过qRT-PCR技术检测灵芝子实体不同部位中这几种糖类的主要代谢酶基因的表达变化,发现这些代谢酶在子实体的菌基部位的表达水平相对其他部位较高,且随着子实体生长这一差异更加显著,这一结果表明灵芝中的糖醇和海藻糖分布差异可能是先由菌基的菌丝体中合成产物并转运到子实体不同部位,再经过一段时间的积累和代谢之后产生。

The fruiting bodies of mushroom usually accumulate high amounts of polyol and trehalose during their growth. However, there are fewer reports about these data in Ganoderma lingzhi. In this research the carbohydrates in fruiting body of G. lingzhi strain SH during growth are tested using HPAEC-PAD method. Results indicate that the main polyol in G. lingzhi SH is arabinitol andmannitol. The content of mannitol peaks in pileus of mature fruiting bodies, and the content of arabinitol peaks in the fruiting bodies when the basidiospores are massively produced. The variation of the content of mannitol and arabinitol shows an adverse trend in brief. The accumulation of one of these two polyol generally results in the decrease of another one. The peak content of trehalose is detected at the base of young fruiting bodies and it maintains a low level in the rest time of growth. The expression level changes of enzymes involving the metabolism of mannitol, arabinitol and trehalose are detected using qRT-PCR. It is found that the expression levels of most of these enzymes are higher in the base of the fruiting bodies than those in other parts of fruiting bodies. This expression disparity is more and more notable with the growth of fruiting bodies. It seems that the polyol and trehalose are mainly synthesized in the mycelia of the base region and then translocate to other regions of the fruiting bodies. After accumulation and consumption during growth, the difference of distribution in different parts of the fruiting bodies occurs.