Response of Phenylethanoid Systems to Photoperiod in Rose Flower Petals

我们发现，参与气味释放的内源分子水平，如酶和挥发性成分，会因光周期而发生变化。在这项研究中，我们的研究重点是阐明2-苯乙醇(2PE)及其β-D-吡喃葡萄糖苷(2PEG)的生物合成途径。我们还试图阐明与玫瑰花瓣气味释放有关的苯乙醇系统，如挥发性化合物、它们的糖苷、酶和基因。依赖PLP的芳香氨基酸脱羧酶(AADC)和苯乙醛脱氢酶的鉴定以L-苯丙氨酸(Phe)为原料合成了苯乙醛(PAR)，它是O2 PE的直接前体。依赖PLP的AADC在好氧条件下与NH_3和H_2O_2一起直接产生PAID。玫瑰花瓣AADC的产量活性显示，对L-Phe的活性比对其D-异构体的活性高9倍。Payed后来通过平价的行动转换为2PE。PAR显示SPE…对几种挥发性醛有更强的毒性，而挥发性化合物中的酮基并没有减少。β-葡萄糖苷酶的分离和性质，该酶参与2PEG的水解制得2PE。我们成功地从玫瑰花瓣中分离到了β-葡萄糖苷酶。酶部分水解后，用TOF-MS/MS对部分多肽序列进行了鉴定。在序列分析的基础上，我们利用Rose EST序列克隆了β-葡萄糖苷酶的全长序列，并在昆虫细胞系统中进行了表达。玫瑰花瓣β-葡萄糖苷酶对几种植物挥发性化合物的β-吡喃葡萄糖苷具有专一性，而对α-吡喃葡萄糖苷、半乳吡喃糖苷、木吡喃糖苷的活性较低。2PE释放量对光周期的响应及LED颜色的影响尽管我们可以追踪完整月季花在整个12L-12D光周期中2PE释放量的变化，但每朵花的2PE释放量是波动的。因此，我们开发了利用玫瑰花瓣来跟踪2PE辐射变化的新方法。观察到2PE的昼夜排泄量至少持续3天。当使用红色LED时，也观察到了类似的模式，尽管蓝色和绿色LED没有这种影响。作为一项持续的研究，2PE释放的调节将基于mRNA表达、酶活性和几个小分子水平的变化来检验。与苯乙醇类系统有关。较少

We have found that the endogenous levels of molecules, such as enzymes and volatile components, involved in the scent emission were changed by the photoperiod. In this research we focused our research to elucidate the biosynthetic pathways of 2-phenylethanol (2PE) and its β-D-glucopyranoside (2PEG). We also tried to clarify the phenylethanoid systems, such as volatile compounds, their glucosides, enzymes, and the genes, being involved in the scent emission from the flower petals of roses.1. Identification of PLP-dependent aromatic amino acid decarboxylase (AADC) and phenvlacetaldehvde reductase. (PAR)Phenylacetaldehyde (PAId), the direct precursor o 2PE, was produced from L-phenylalanine (Phe). PLP-dependent AADC directly produced PAId together with NH_3 and H_2O_2 under aerobic conditions. The activity of rose petal AADC to yield PAId showed nine times higher activity toward L-Phe than toward its D-isomer. PAId was subsequently converted to 2PE by the action of PAR. The PAR showed spe … More cificity toward several volatile aldehydes, whereas ketone groups of the volatile compounds were not reduced at all.2. Isolation and characterization of β-glucosidase, involved in the hydrolysis of 2PEG to produce 2PE.We have successfully isolated β-glucosidase from the flower petals of roses. The partial peptide sequences were characterized by TOF-MS/MS after the partial hydrolysis of the enzyme. Based on the analysis of the sequences, we have cloned the full-length β-glucosidase using the Rose EST sequence, and expressed the gene in the insects cell systems. The rose petal β-glucosidase showed a specificity toward β-glucopyranoside of several plant volatile compounds, whereas the activity toward the α-glucopyranosides, galactopyranosides, xylopyranosides, were quite low.3. Response of 2PE emission toward Photoperiod and the effects of LED-colorsAlthough we could trace the change in the 2PE emission from the flowers of intact rose plants throughout 12L-12D-photoperioc, the amount of 2PE emitted from each flower was fluctuated. Thus we have developed the new methods to trace the change in the 2PE emission by using flower petals of roses. The diurnal emission of 2PE was observed for at least three days. The similar patter was observed when Red LED was used, although blue and green LED did not have such effects. As a continuing research, the regulation of 2PE emission will be examined based on mRNA expression, enzymatic activity and change in the levels of several small molecules. involved in the phenylethanoid systems. Less