【摘要】 用RT-PCR和RACE(rapidamplificationofcDNAends)技术相结合,从香菇(Lentinulaedodes)苏香菌株中得到了1个与低温胁迫相关的全长2432bp的cDNA,该基因含1个1962bp的开放式阅读框,基因组序列分析发现该基因有11个内含子。经数据库同源查找及序列比较,发现该基因编码的氨基酸与青霉菌(Penicilliumnordicum)的聚酮合酶和酿酒酵母(Saccha-romycescerevisiae)的α-氨基己二酸还原酶分别具有30%、22%的同源性和46%、40%的相似性。表达谱分析表明,当低温胁迫的温差为5℃时,该基因即开始表达,但mRNA丰度较低;温差达到10℃时,mRNA达到最大表达量;低温胁迫处理后,该基因在菌丝转色前的表达丰度低于转色后的丰度。将该基因初步命名为ICS(geneinducedundercoldstress,GenBank登录号为DQ211659),并初步推测该基因可能参与了低温胁迫的信号传导,低温胁迫信号在影响氮代谢后进而诱发子实体的形成。更多还原

【Abstract】 Fruiting body development in Lentinula edodes ((Berk.) Pegler) depends on temperature alterations, and cold stress leads to differential expression of related genes. Differential display PCR and rapid amplification of cDNA ends (RACE) were used to clone the full-length cDNA of a cold stress-responding gene. The cDNA contained an open reading frame of 2432 bp encoding 654 amino acids, and the deduced amino acid sequence showed overall homologies of 46% and 40% with polyketide reductase from Penicillium nordicum and α-aminoadipate reductase from Saccharomyces cerevisiae, respectively. Comparison of the genomic and cDNA sequences indicated the presence of 12 extrons and 11 introns. Significant levels of gene expression were detected at 20 ℃ but transcription increased after mycelium was subjected to cold stress and changed colour from white to brown at 15 ℃. The cloned gene, tentatively designated ICS (induced under cold stress, GenBank accession No. DQ211659), may play a role in transmitting signals related to cold stress. The above results suggest that its role in fruiting initiation may be linked to changes in nitrogen metabolism and provide a new candidate gene for hypothesis-based investigations of the cold stress response and the onset of fruiting.更多还原