Key Laboratory of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China
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.
