Lindahl Björn D, Taylor Andy F S
Department of Forest Mycology and Pathology, SLU, Box 7026, SE-750 07 Uppsala, Sweden.
New Phytol. 2004 Oct;164(1):193-199. doi: 10.1111/j.1469-8137.2004.01147.x.
• The genetic potential of ectomycorrhizal fungi to produce N-acetylhexosaminidases was investigated here. N-acetylhexosaminidases are enzymes that cleave monosaccharides from oligomers of N-acetylhexosamines and play an important role in the degradation of chitin. • Degenerate PCR-primers were designed against genes coding for N-acetylhexosaminidases in basidiomycetes. PCR was performed with DNA templates extracted from sporocarps of 26 ectomycorrhizal fungal species and two saprotrophs. • PCR-products were obtained from 18 species representing 12 genera distributed throughout the basidiomycete phylogeny. Sequencing confirmed that the products were homologous with N-acetylhexosaminidase genes from plants, animals and other fungi. Some species yielded two PCR-products representing isoenzymes. • Chitin constitutes a potentially important nitrogen source in soil. Our results demonstrate that a wide range of ectomycorrhizal fungi have the genetic potential to produce N-acetylhexosaminidases, and the expression of this potential would enable them to exploit polymers of amino sugars as a source of nitrogen for themselves and their host plants.
• 本文研究了外生菌根真菌产生N - 乙酰己糖胺酶的遗传潜力。N - 乙酰己糖胺酶是一种能从N - 乙酰己糖胺寡聚物中切割单糖的酶，在几丁质降解中起重要作用。
• 针对担子菌中编码N - 乙酰己糖胺酶的基因设计了简并PCR引物。用从26种外生菌根真菌和两种腐生菌的子实体中提取的DNA模板进行PCR。
• 从代表担子菌系统发育中12个属的18个物种中获得了PCR产物。测序证实这些产物与来自植物、动物和其他真菌的N - 乙酰己糖胺酶基因同源。一些物种产生了代表同工酶的两种PCR产物。
• 几丁质是土壤中一种潜在的重要氮源。我们的结果表明，广泛的外生菌根真菌具有产生N - 乙酰己糖胺酶的遗传潜力，这种潜力的表达将使它们能够利用氨基糖聚合物作为自身及其寄主植物的氮源。
