Identification and expression analysis of WRKY gene family in eukaryotic algae / 生物工程学报

WRKY is a superfamily of plant-specific transcription factors, playing a critical regulatory role in multiple biological processes such as plant growth and development, metabolism, and responses to biotic and abiotic stresses. Although WRKY genes have been characterized in a variety of higher plants, little is known about them in eukaryotic algae, which are close to higher plants in evolution. To fully characterize algal WRKY family members, we carried out multiple sequence alignment, phylogenetic analysis, and conserved domain prediction to identify the WRKY genes in the genomes of 30 algal species. A total of 24 WRKY members were identified in Chlorophyta, whereas no WRKY member was detected in Rhodophyta, Glaucophyta, or Bacillariophyta. The 24 WRKY members were classified into Ⅰ, Ⅱa, Ⅱb and R groups, with a conserved heptapeptide domain WRKYGQ(E/A/H/N)K and a zinc finger motif C-X4-5-C-X22-23-H-X-H. Haematococcus pluvialis, a high producer of natural astaxanthin, contained two WRKY members (HaeWRKY-1 and HaeWRKY-2). Furthermore, the coding sequences of HaeWRKY-1 and HaeWRKY-2 genes were cloned and then inserted into prokaryotic expression vector. The recombinant vectors were induced to express in Escherichia coli BL21(DE3) cells and the fusion proteins were purified by Ni-NTA affinity chromatography. HaeWRKY-1 had significantly higher expression level than HaeWRKY-2 in H. pluvialis cultured under normal conditions. High light stress significantly up-regulated the expression of HaeWRKY-1 while down-regulated that of HaeWRKY-2. The promoters of HaeWRKY genes contained multiple cis-elements responsive to light, ethylene, ABA, and stresses. Particularly, the promoter of HaeWRKY-2 contained no W-box specific for WRKY binding. However, the W-box was detected in the promoters of HaeWRKY-1 and the key enzyme genes HaeBKT (β-carotene ketolase) and HaePSY (phytoene synthase) responsible for astaxanthin biosynthesis. Considering these findings and the research progress in the related fields, we hypothesized that the low expression of HaeWRKY-2 under high light stress may lead to the up-regulation of HaeWRKY-1 expression. HaeWRKY-1 may then up-regulate the expression of the key genes (HaeBKT, HaePSY, etc.) for astaxanthin biosynthesis, consequently promoting astaxanthin enrichment in algal cells. The findings provide new insights into further analysis of the regulatory mechanism of astaxanthin biosynthesis and high light stress response of H. pluvialis.

Chemical constituents of Galium verum / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the chemical constituents of the extract of Galium verum.</p><p><b>METHOD</b>The compounds were isolated by chromatography and identified by spectral data.</p><p><b>RESULT</b>The eleven compounds obtained were identified as (+)-pinoresinol 4,4'-O-bis-beta-D-glucopyranoside (1), epipinoresinol (2), (+) -medioresinol (3), isorhamnetin (4), isorhamnetin 3-O-alpha-L-rhamnopyranosyl-(1-6)-beta-D-glucopyranoside (5), diosmetin (6), diosmetin 7-O-beta-D-glucopyranoside (7), quercetin-3-O-beta-D-glucopyranoside (8), ursolic acid (9), ursolic aldehyde (10) and rubifolic acid (11).</p><p><b>CONCLUSION</b>Compounds 1-5 and 9-11 were isolated from this genus for the first time.</p>

Chemical constituents from fruits of Ailanthus altissima / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the chemical constituents from the extract of the fruits of Ailanthus altissimrna.</p><p><b>METHOD</b>Twelve compounds were isolated by chromatography and identified by spectral data.</p><p><b>RESULT</b>The compounds obtained were identified as (+)-isolariciresinol (1), isolariciresinol 9-O-beta-D-glucopyranoside (2), gallic acid (3), D-sorbitol (4), vanillin (5), 6,7-dihydroxy-coumarin (6), stigmast-4-en-3-one (7), 5alpha, 8alpha-epidioxy-ergosta-6,9 (11), 22E-trien-3beta-ol (8), ergosta-4,6,8 (14), 22E-tetraen-3-one (9), cycloeucalenol (10), lupeol (11), betulinic acid (12).</p><p><b>CONCLUSION</b>Compounds 1-12 were isolated from this genus for the first time.</p>

Chemical constituents in fruits of Ailanthus altissima / 中草药

Objective To isolate and identify the chemical constituents of 95% alcohol extract in the fruits of Ailanthus altissima. Methods The compounds were prepared by repurification and their structures were identified by physicochemical properties and spectral analyses. Results Nine compounds were isolated and identified as ailanthone A [11?, 20-epoxy-1?, 2?, 12?-pentahydroxypicrasa-3, 13(21)-dien-16-one, Ⅰ], olean-9(11), 12-dien-3?-ol (Ⅱ), D-friedoolean-14-en-3-one (Ⅲ), ?-amyin (Ⅳ), cycloart-25-ene-3?,24?-diol (Ⅴ), hopane-3-one-22-ol (Ⅵ), n-tetratriacontane (Ⅶ), L-evonymitol (Ⅷ), D-mannitol (Ⅸ). Conclusion Among them Ⅱ- Ⅸ are isolated from the plants of Ailanthus Desf. nom. Conserv. for the first time.