Response of Phenylethanoid Systems to Photoperiod in Rose Flower Petals

我们发现，参与气味释放的内源性分子水平，如酶和挥发性成分，随着光周期的变化而改变。在本研究中，我们的研究重点是阐明2-苯乙醇（2PE）及其β- d -葡萄糖苷（2PEG）的生物合成途径。我们还试图澄清苯乙醇系统，如挥发性化合物，它们的糖苷，酶和基因，参与玫瑰花瓣的气味释放。plp依赖性芳香氨基酸脱羧酶（AADC）和苯乙醛还原酶的鉴定。以l -苯丙氨酸（Phe）为原料制备了2PE的直接前体苯乙醛（PAId）。plp依赖性AADC在好氧条件下直接与NH_3和H_2O_2合成PAId。玫瑰花瓣AADC对l -苯丙氨酸的活性是其d -异构体的9倍。pay随后在PAR的作用下转化为2PE。PAR对几种挥发性醛类化合物表现出更强的亲和性，而挥发性化合物的酮基根本没有被还原。参与2PEG水解生成2PE的β-葡萄糖苷酶的分离与表征。我们成功地从玫瑰花瓣中分离出β-葡萄糖苷酶。酶部分水解后，用TOF-MS/MS对部分肽序列进行了表征。在对序列分析的基础上，利用玫瑰EST序列克隆出β-葡萄糖苷酶全长，并在昆虫细胞系统中表达。2 .玫瑰花瓣β-葡萄糖苷酶对几种植物挥发性化合物中的β-葡萄糖苷具有特异性，而对α-葡萄糖苷、半乳糖糖苷、木pyrano苷的活性较低。2PE发射对光周期的响应及led颜色的影响虽然我们可以追踪完整玫瑰植株在12l - 12d光周期内的2PE发射变化，但每朵花的2PE发射量是波动的。因此，我们开发了利用玫瑰花瓣来追踪2PE发射变化的新方法。观察到2PE的日发射至少三天。当使用红色LED时，也观察到类似的模式，尽管蓝色和绿色LED没有这种效果。作为一项持续的研究，将基于mRNA表达、酶活性和几种小分子水平的变化来研究2PE发射的调控。涉及到苯乙醇系统。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