Szeto Carol Y Y, Wong Queenie W L, Leung Grace S, Kwan H S
Molecular Biotechnology Programme, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China.
Mycol Res. 2008 Jan;112(Pt 1):108-16. doi: 10.1016/j.mycres.2007.08.024. Epub 2007 Nov 21.
Le.nik1, a two-component histidine kinase gene of Lentinula edodes, the Shiitake mushroom, was identified. The relationship between this two-component signal transduction system and mushroom development was studied. We used a modified RNA arbitrarily-primed PCR (RAP-PCR) method to isolate Le.nik1 as a differentially expressed gene during L. edodes development. We determined the 6.29kb full-length cDNA sequence of Le.nik1. It had high sequence homology to Neurospora crassa nik1, which encoded a histidine kinase essential for development and osmotic response. In L. edodes, the expression level of Le.nik1 was highest during primordium formation and fruiting body maturation. The transcripts were localized predominantly in the developing hymenophores, or mushroom gills, which may indicate the role of a two-component signal transduction system in cell differentiation during mushroom development. Mannitol stress influenced transcript expression of Le.nik1, suggesting that it may be involved in osmo-sensing and regulation. To our knowledge, this is the first report on the two-component system in mushrooms and the first analysis on the distribution of Le.nik1 transcript in the course of fruiting body formation and in parts of fruiting bodies.
香菇（Lentinula edodes）的双组分组氨酸激酶基因Le.nik1已被鉴定。研究了该双组分信号转导系统与蘑菇发育之间的关系。我们采用改良的RNA任意引物PCR（RAP-PCR）方法，将Le.nik1作为香菇发育过程中的差异表达基因进行分离。我们测定了Le.nik1的6.29kb全长cDNA序列。它与粗糙脉孢菌（Neurospora crassa）的nik1具有高度的序列同源性，后者编码一种对发育和渗透反应至关重要的组氨酸激酶。在香菇中，Le.nik1的表达水平在原基形成和子实体成熟期间最高。转录本主要定位于发育中的菌褶，即蘑菇的鳃，这可能表明双组分信号转导系统在蘑菇发育过程中的细胞分化中发挥作用。甘露醇胁迫影响Le.nik1的转录本表达，表明它可能参与渗透感知和调节。据我们所知，这是关于蘑菇双组分系统的首次报道，也是对Le.nik1转录本在子实体形成过程中和子实体部分的分布的首次分析。
