香菇漆酶活性及转录表达对不同温度的响应特征

Effects of different temperature cultures on laccase activity and transcriptional expression of Letinous edodes

摘要:

以香菇新808为材料,研究不同温度培养下漆酶活性及其基因表达调控特征.通过平板培养法测定4种温度（20℃、25℃、28℃和30℃）对香菇菌丝圈及氧化圈的影响,通过液体发酵测定漆酶活性,并采用qPCR技术检测漆酶同工酶基因的相对表达量.结果表明:不同温度条件下,漆酶的活性及转录表达存在明显差异.25℃培养条件下香菇菌丝圈及氧化圈最大,漆酶活性最强（114.11 U/mL）;而30℃时的菌丝圈和氧化圈最小,漆酶活性低（47.52 U/mL）.不同温度培养下漆酶同工酶基因出现差异性表达,以25℃为对照组,20℃培养条件下9个漆酶基因（Llac1-3、Llac5和Llac7-11）表达量上调,28℃处理下除Llac5和Llac7基因以外,其余8个漆酶基因表达量发生上调,而30℃处理组6个漆酶基因（Llac1-2、Llac4、Llac7-8和Llac10）表达量下调.表明20℃处理下有助于漆酶基因的表达,而30℃处理下则抑制了其同工酶基因的表达.

Abstract:

The laccase activity and its gene expression regulation characteristics under different temperature cultures (20℃, 25℃, 28℃and 30℃) were studied with the Lentinus edodes Xin808 to analyze the effect of its diameter of the mycelium ring and oxidation ring. The laccase activity was measured by liquid fermentation, and the relative expression level of lac was detected by qPCR technique. The results showed that, the growth rate of Lentinus edode mycelium, formation of oxidation ring, and laccase activity were all higher under 25℃ cultivation temperature. While 30℃ inhibited the growth of mycelium and the formation of oxidation ring and resulted into the lowest laccase activity. Moreover, the Lac genes exhibited differential expression profiles cultured in different temperature. Compared to the 25℃(control), the relative expression level of 9 laccase genes (i.e. Llac1-3, Llac5 and Llac7-11) were up-regulated cultured at 20℃. Besides, the expression level of genes such as Llac5, Llac7, and the rest 8 laccase genes were up-regulated at 28℃. While 6 genes (including Llac1-2, Llac4, Llac7-8 and Llac10) were down-regulated under 30℃ treatment. It can promote Llac genes expression cultured at 20℃ , while 30℃ treatment inhibit the expression of the isozyme genes.