分离自黑茶的散囊菌属真菌中的NRPS基因的检测和分布

Detection and distribution of NRPS genes in Eurotium spp. isolated from dark tea

摘要:

【目的】检测源自黑茶的散囊菌属分离菌株中的NRPS基因, 推测它们相应的次级代谢产物合成能力, 并考察了基于NRPS基因分布特征进行散囊菌属真菌遗传多样性分析的可能性。【方法】运用IQS法提取来自湖南、四川和湖北等地黑茶样品的14株散囊菌(Eurotium spp.)菌株的总DNA, 利用特异性引物对菌株中11种NRPS基因片段进行PCR检测和序列分析, 并结合UPGMA法分析了NRPS基因的分布。【结果】各菌株分别含有4?10个NRPS基因片段。NRPS7、CPS1基因在所有菌株中都可以检测到, 而NRPS2、NRPS6基因则仅在个别菌株中检测到; 其它NRPS基因的分布则呈现出多样性。来自同一块砖茶的菌株Fw-30813-7、Fw-30813-4、Fw-30813-1和Fw-30925-5之间, NRPS1、NRPS2、NRPS3、NRPS4和NRPS8五个基因的分布存在差异, 显示出黑茶内散囊菌的遗传多样性。来自湖南白沙溪茶厂的茯砖样品的菌株Fa-20719-3不含有NRPS5和NRPS8基因; 而从湖南益阳茶厂茯砖茶7个分离菌株中均含有这两种基因。不同地点加工出来的黑茶样品中的散囊菌菌株之间存在一些明显的遗传差异。【结论】首次从我国黑茶中的散囊菌属分离菌株中检测到NRPS基因, 并推测了NRPS产物的多样性, 展示了其多样化分布特征, 提示NRPS基因的分析有可能成为衡量散囊菌遗传多样性的另一个尺度。

Abstract:

[Objective] NRPS genes in 14 Eurotium spp. strains obtained from dark tea samples were detected. The potential of secondary metabolite biosynthesis mediated by some NRPS genes were predicted. Distributive characteristics of NRPS genes may be useful for understanding the genetic diversity of Eurotium spp.. [Methods] Fourteen Eurotium strains were obtained from dark tea samples. Fungal genomic DNA samples were extracted by IQS DNA extraction method. Distribution of 11 NRPS genes were detected by specific DNA primers for these strains by PCR and analyzed by DNA sequencing and sequence analyses. UPGMA was conducted to discuss distribution pattern of NRPS genes. [Results] Numbers of NRPS genes involved in Eurotium strains tested were ranged from 4 to 10. NRPS7 and CPS1 genes were detected from all the Eurotium strains, while NRPS2 and NRPS6 genes were only detected in few strains, and other NRPS genes diverse. Fw-30813-1, Fw-30813-4, Fw-30813-7 and Fw-30925-5 from the same tea brick were different each other in detection of NRPS1, NRPS2, NRPS3, NRPS4 and NRPS8 genes, demonstrating an extremely high genetic diversity in Eurotium spp. from dark teas. NRPS5 and NRPS8 genes were not detected from strain Fa-20719-3 from Fuzhuan samples made in Baishaxi, Hunan, while detected from all of 7 strains obtained from Fuzhuan samples made in Yiyang, Hunan. Distinct genetic differences were demonstrated among Eurotium strains obtained from separate manufactures and sites. [Conclusion] Detection and distribution and genetic diversity of NRPS genes were first reported from Eurotium strains obtained from Chinese dark tea. Detection of NRPS genes could be effective as an easy method to evaluate genetic diversity of Eurotium spp..