Dihydroquercetin accumulation in the medium of some wild carrot culture subclones

Approximately half of the subclones examined from one clone of the wild carrot cell culture WC63-1-9-1 accumulated dihydroquercetin in the culture medium. The amount of dihydroquercetin accumulated in the medium varied with the subclone used, the size of the inoculum, the medium used and the time of sampling.Dedicated to Dr. Friedrich Constabel on the occasion of his 60th birthday     

Chalcone synthase cosuppression phenotypes in petunia flowers: comparison of sense vs. antisense constructs and single-copy vs. complex T-DNA sequences

Flower pigmentation patterns were scored in 185 senseChalcone synthase (Chs) transgenotes and 85 antisenseChs transgenotes; upon first flowering, 139 (75%) of sense transgenotes were found to be phenotypically altered, as were 70 (82%) of the antisense transgenotes. The observed patterns document the range of phenotypic variations that occur, as well as confirm and extend the finding that senseChs constructs produce several types of morphologybased based flower pigmentation patterns that antisenseChs constructs do not. Long-term monitoring for epigenetic variations in one population of 44 senseChs transgenotes showed that 43 (98%) were capable of producing a cosuppression phenotype. The primary determinant of sense-specific patterns of cosuppression ofChs was found to be the repetitiveness and organization pattern of the transgene, not position effects by, or readthrough from, flanking plant DNA sequences. The degree of cosuppression observed in progeny of transgenotes carrying multiple, dispersed copies as compared to that observed with a single copy of the transgene suggests that sense cosuppression ofChs is subject to a transgene dosage effect.     

Genetical and biochemical evidence that the hydroxylation pattern of the anthocyanin B-ring in Silene dioica is determined at the p-coumaroyl-coenzyme a stage

In petals of Silene dioica, gene P controls the 3′-hydroxylation of the anthocyanin B-ring and the hydroxylation pattern of the hydroxycinnamoyl acyl group bound to the 4″'-hydroxyl group of rhamnose of anthocyanidin 3-rhamnosyl(1→6)glucoside-5-glucoside. In this paper, experiments are presented which show that gene P is involved in the hydroxylation of p-coumaroyl-CoA to caffeoyl-CoA, which is then used both as a precursor in anthocyanin biosynthesis and as a substrate for the final acylation.     

Effect of temperature on phytochrome—mediated anthocyanin synthesis in red cabbage

Abstract. A brief high temperature treatment (45 C) promoted anthocyanin synthesis in 2-d-old dark-grown red cabbage seedlings. The increased effectiveness of a temperature/red light treatment as opposed to the reverse sequence suggests that an elevated temperature 'induces' some component which facilitates the phytochrome response.     

The effect of membrane stabilizers on phytochrome-controlled anthocyanin biosynthesis in Brassica oleracea

The promotion of anthocyanin synthesis in red-cabbage seedlings by 5 min exposure to R light is inhibited by subsequent application of CaCl₂. The stimulation of dark synthesis of anthocyanin by n-PrOH and by kinetin is also reduced by Ca²⁺ and by cholesterol, both of which are well known to stabilize cell membranes. By contrast, EDTA, which chelates Ca²⁺, promotes dark synthesis of anthocyanin. Assay of native Ca²⁺ extractable from seedlings immersed in EDTA demonstrates that R light exposure promotes a highly significant increase in extractable Ca²⁺. It is suggested that the molecular configuration of the phytochrome molecule affects the ability of a membrane to bind Ca²⁺ and that this in turn affects the permeability to substrates which are required for anthocyanin biosynthesis.     

基于转录组测序的细风轮花青素合成途径及关键酶基因分析

为进一步理解细风轮花青素合成途径,本研究利用华大基因BGISEQ-500平台对细风轮中的根、茎、叶、花4个组织进行了转录组测序,从头组装后得到128 856个Unigene。KEGG通路表明有40个Unigene编码了细风轮的花青素生物合成途径中6个关键酶。我们对其中的关键酶DFR（二氢黄酮醇还原酶）进行同源比对和空间结构模拟,结果显示DFR序列和结构均具有良好的保守性,且具有高度保守的NAD⁺结合位点,其二级结构主要由α螺旋和β折叠组成,在空间上α螺旋包裹着β折叠,形成“夹心饼干”样结构。