香菇ALDH家族基因鉴定、表达及功能分析

Identification,Expression and Function Analysis of ALDH Gene Family in Lentinula edodes

在已发表的香菇(Lentinulaedodes)4个基因组W1-26、NBRC111202、Bin0899和B17中分别鉴定到17、20、19和18个ALDH家族成员,其编码蛋白分属于11个家族,其中家族1成员数量最多。这些ALDH基因分别分布于17、16、16和10个scaffold中,在除W1-26外的其他3个基因组中均存在1~2对串联重复ALDH基因。香菇与模式真菌裂褶菌(Schizophyllum commune)之间仅存在4对共线性ALDH基因。启动子分析发现香菇W1-26基因组中17个ALDH基因具有光、激素、氧及干旱等10种响应元件,其中光响应元件数量显著多于其他元件。转录组和蛋白质组数据显示,LeW1-26ALDH1N1、LeW1-26ALDH3L1及LeW1-26ALDH6C1对热胁迫不同时间具有显著响应。LeW1-26ALDH3L1基因RNAi转化子与野生型S606菌株相比,在40℃热胁迫24 h条件下菌丝IAA含量显著下降了55%,25℃下菌丝恢复生长速度显著下降了71%,菌丝生物量显著下降了45%,LeW1-26ALDH1N1和LeW1-26ALDH6C1基因RNAi转化子与野生型相比表型无显著改变。以上结果说明LeW1-26ALDH3L1基因表达水平的下降可能导致热胁迫下菌丝IAA含量降低进而影响菌丝耐热能力。

In this study,17,20,19,and 18 ALDH family members were identified in the four published genomes W1-26,NBRC111202,Bin0899,and B17 of Lentinula edodes,respectively.ALDH encoded proteins belong to 11 families,among which family 1 has the largest number of genes.These ALDH genes were distributed in 17,16,16,and 10 scaffolds of four genomes,respectively,and one or two pairs of tandem duplication ALDH genes were found except W1-26 genome.Only four pairs collinear ALDH genes existed between L.edodes and the model fungus Schizophyllum commune.The promoter regions of 17 ALDH genes in the W1-26 genome of L.edodes contained ten kinds of response elements such as light,hormone,oxygen and drought,among which the number of light response elements was significantly more than other elements.The transcriptome and proteome data showed that LeW1-26ALDH1N1,LeW1-26ALDH3L1 and LeW1-26ALDH6C1 had significant responses to different time periods of heat stress.Compared with wild-type S606 strain,LeW1-26ALDH3L1 gene RNAi transformant had 55%decrease of IAA content of mycelia after heat stress at 40℃for 24 h,and had 71%and 45%decrease of mycelial regrowth rate and biomass separately at 25℃.These phenotypes of LeW1-26ALDH1N1 and LeW1-26ALDH6C1 gene RNAi transformants did not change compared with wild-type S606 strain.Above all,it is indicated that the decreased gene expression level of LeW1-26ALDH3L1 may lead to mycelia’s lower IAA content under heat stress,and then reduced the thermotolerance of mycelia.