低温胁迫诱导肺形侧耳合成麦角甾醇的通路分析

Cold stress induction of ergosterol biosynthesis in Pleurotus pulmonarius

本文以肺形侧耳栽培菌株X57为研究对象,对其低温胁迫时期进行转录组分析,发现差异基因显著地富集到麦角甾醇合成通路。根据麦角甾醇合成通路的相关信息,在肺形侧耳中筛选出该通路的17个基因,并推测了肺形侧耳的麦角甾醇合成通路。利用荧光定量研究了X57栽培袋在低温处理下该通路上各个基因的表达,结果显示随着低温胁迫时间的增加,该通路上大部分基因的表达量持续上升,且差异显著。检测栽培袋中菌丝麦角甾醇含量发现,低温胁迫显著提高麦角甾醇的含量,与RNA-Seq分析结果一致。此外,以无需打冷也能整齐出菇的野生菌株X1为对照,比较X57与X1的麦角甾醇基因对冷胁迫的响应情况,探究麦角甾醇合成通路是否在肺形侧耳低温诱导形成原基时期具有关键性作用。将X57与X1菌株置于PDA平板上培养并进行低温胁迫,利用荧光定量PCR对各个基因表达进行验证,结果显示两个菌株的麦角甾醇合成通路相关基因均对低温胁迫有响应,X57低温胁迫时通路中绝大多数基因的表达量上升,且大部分基因表达量提高2倍以上;X1菌株的通路中的表达量变化较小。由此推测麦角甾醇通路在肺形侧耳变温结实中低温刺激形成原基有一定作用,为深入研究肺形侧耳低温胁迫调控分子机理提供了重要的基础。

Transcriptome in association with the low-temperature stress of Pleurotus pulmonarius cultivar X57 was investigated.It was found that the differentially expressed genes were significantly enriched in the ergosterol biosynthesis pathway.According to the information of the ergosterol biosynthesis pathway in P.pulmonarius,17 genes were screened and the pathway in P.pulmonarius was constructed.qRT-PCR was used to study the expression of each gene in this pathway under the condition of low-temperature treatment.The results showed that the expression level of most genes in this pathway continuingly increased with the prolongation of low-temperature stress,and the content of ergosterol in mycelia in cultivation bags increased significantly under low-temperature,being consistent with the results of RNA-Seq analysis.The response of ergosterol genes of X57 and X1 to cold stress was compared with that of wild strain X1 fruiting without cold stress to explore whether ergosterol synthesis pathway played a key role in the formation of primordia of P.pulmonarius.The X57 and X1 strains were cultured on PDA plates and subjected to low-temperature stress.The expression of each gene was verified by qPCR and the results showed that the genes related to the ergosterol biosynthesis pathway of both strains responded to low-temperature stress significantly.The X57 responded strongly and the expression of most genes in this pathway increased by more than 3 times under low-temperature stress;however,the response of X1 strain was lower.It is concluded that ergosterol pathway plays an important role in the formation of primordia during low-temperature stimulation in P.pulmonarius,and our result provides an important basis for further study on the molecular mechanism of responding low-temperature stress of P.pulmonarius.