武夷岩茶加工过程中β-樱草糖苷酶和β-葡萄糖苷酶基因表达与香气前体物质的差异性

Differential gene expression analysis of β-primeverosidase and β-glucosidase genes and aroma precursors in Wuyi rock tea machining process

研究水仙和肉桂2种武夷岩茶加工过程中糖苷类香气前体物质的变化以及β-樱草糖苷酶和β-葡萄糖苷酶基因表达的差异性.结果表明:肉桂香气前体物质总量是水仙的0.80~1.93倍,香气前体物质总量变化具有差异性;水仙β-樱草糖苷酶基因平均相对表达量(1.10)低于β-葡萄糖苷酶基因(1.90),晒青过程中β-樱草糖苷酶和β-葡萄糖苷酶基因的相对表达量显著高于鲜叶,做青过程中的变化未达到显著水平;肉桂β-樱草糖苷酶基因的平均相对表达量(0.54)低于β-葡萄糖苷酶基因(0.76),晒青过程中β-樱草糖苷酶和β-葡萄糖苷酶基因的相对表达量与鲜叶比较未达到显著水平,做青结束后达到显著水平.水仙2个基因和肉桂β-樱草糖苷酶基因的相对表达量与香气前体物质总量及各糖苷成分含量变化总体一致.

To investigate the molecular mechanism of aromatic compound formation in Wuyi rock tea, differential expression of gly-cosidic aroma precursors,β-primeverosidase and β-glucosidase genes were analyzed in Shuixian and Rougui manufacturing process. The results indicated that total amount of aroma precursors of Rougui was 0.80-1.93 times as high as that of Shuixian, and they var-ied significantly during manufacturing process. Averagely, relative expression of β-primeverosidase gene （1.10） was less than β-glu-cosidase （1.90） for Shuixian. During sun-withering process, relative expressions of β-primeverosidase and β-glucosidase genes in-creased significantly compared with fresh leaves, and their difference did not reach significant level in tea leaf shaking stage. In Rou-gui, relative expression of β-primeverosidase gene （0.54） was less than β-glucosidase （0.76）. Relative expressions of β-primeverosi-dase and β-glucosidase genes did not change much compared with those of fresh leaves, but they rised significantly in tea leaf sha-king stage. Changes in gene expressions of β-primeverosidase and β-glucosidase in Shuixian and β-glucosidase in Rougui showed the same trend with glycosidic aroma precursors.