生物技术通报 ›› 2019, Vol. 35 ›› Issue (2): 39-45.doi: 10.13560/j.cnki.biotech.bull.1985.2018-0842

• 研究报告 • 上一篇    下一篇

pH对香菇多糖含量及合成关键酶基因转录水平的影响

王杰1, 张阳2, 秦澎1, 何茂兰1, 李津1, 辜运富1, 曾先富3, 向泉桔1   

  1. 1. 四川农业大学资源学院微生物系,成都 611130;
    2. 四川农业大学农学院,成都 611130;
    3. 成都市农林科学院园艺研究所,成都 611130
  • 收稿日期:2018-09-28 出版日期:2019-02-26 发布日期:2019-03-07
  • 作者简介:王杰,男,硕士研究生,研究方向:微生物资源与分子生物学;E-mail:1060404419@qq.com
  • 基金资助:
    四川省教育厅重点项目(15ZA0013),四川省科技支撑计划项目(2016NYZ0040),四川农业大学大学生创新训练计划(1510626036)

Effects of pH on the Lentinan Content and the Transcriptional Levels of Genes Related to the Synthesis of Key Enzymes in Lentinula edodes

WANG Jie1, ZHANG Yang2, QIN Peng1, HE Mao-lan1, LI Jin1, GU Yun-fu1, ZENG Xian-fu3, XIANG Quan-ju1   

  1. 1. Department of Microbiology,College of Resources,Sichuan Agricultural University,Chengdu 611130;
    2. Agricultural College,Sichuan Agricultural University,Chengdu 611130;
    3.Institute of Horticulture,Chengdu Academy of Agricultural and Forestry Sciences,Chengdu 611130
  • Received:2018-09-28 Published:2019-02-26 Online:2019-03-07

摘要: 香菇是一种药食两用真菌,其主要代谢产物香菇多糖具有较高药用价值,研究香菇多糖代谢途径对提高香菇多糖含量具有较大参考价值。以香菇新808为材料,苯酚-硫酸法测定不同pH发酵条件下香菇多糖的含量,通过荧光定量PCR及3个软件(GeNorm、NormFinder和BestKeeper)筛选出了不同pH条件香菇稳定表达的内参基因,并以此为基础分析多糖代谢途径中3个关键酶基因的转录表达水平。结果表明,在实验用pH值范围内(5.0-7.0),香菇菌丝体生物量和胞内多糖含量随着pH值的升高而增加,而胞外多糖含量则呈下降趋势;18S和rpl4分别被鉴定为不同pH发酵条件下最稳定和最不稳定表达的内参基因。不同pH发酵条件UDP-葡萄糖焦磷酸化酶基因(UGP)的相对表达量明显高于葡萄糖磷酸变位酶基因(PGM)与葡萄糖磷酸异构酶基因(PGI);PGM相对表达量小且稳定,PGI相对表达量较小,但随pH值的变化波动较大。不同pH对香菇生物量及多糖含量的影响存在差异,3个关键酶基因的转录表达水平与多糖含量之间无明显相关性。

关键词: 香菇多糖, pH值, 内参基因, 相对表达量

Abstract: Lentinula edodes is a fungus as both medicine and food. Its main metabolite,lentinan,has great medicinal value. It is of great significance to study the metabolic pathways of lentinan biosynthesis for improving the content of lentinan. With Xin808 as the material,phenol-sulfuric acid method was used to measure the lentinan content under different pH fermentation conditions,and fluorescence quantitative PCR and three software(GeNorm,NormFinder and BestKeeper)were adapted to screen the stably expressed reference genes. Based on those,the transcriptional expression levels of 3 key enzyme genes in polysaccharide metabolic pathways were analyzed. The results showed that the biomass and intracellular polysaccharide of mycelium increased with the increase of pH,while the extracellular polysaccharide decreased. 18S and rpl4 were determined as the most stable and unstable reference genes,respectively. In the range of pH 5.0-7.0,the relative expression level of UGP was obviously higher than that of PGM and PGI,low-level and stable expression profile of PGM was detected,and the relative expression of PGI was low,but fluctuated with the variation of pH value. In sum,the variation of pH value resulted in the various effects on the biomass and polysaccharide content of L. edodes,and there was no correlation between the transcriptional expression level of 3 key enzyme genes and polysaccharide content in this study.

Key words: lentinan, pH value, reference gene, relative expression level