[Identification and expression analysis of whole gene family of Isatis indigotica 4-coumarate: CoA ligase].

The 4-coumarate: CoA ligase(4CL) is a key enzyme in the upstream pathway of phenylpropanoids such as flavonoids, soluble phenolic esters, lignans, and lignins in plants. In this study, 13 4CL family members of Arabidopsis thaliana were used as reference sequences to identify the 4CL gene family candidate members of Isatis indigotica from the reported I. indigotica genome. Further bioinformatics analysis and analysis of the expression pattern of 4CL genes and the accumulation pattern of flavonoids were carried out. Thirteen 4CL genes were obtained, named Ii4CL1-Ii4CL13, which were distributed on chromosomes 1, 2, 3, 4, and 6. The analysis of the gene structure and conserved structural domains revealed the intron number of I. indigotica 4CL genes was between 1 and 12 and the protein structural domains were highly conserved. Cis-acting element analysis showed that there were multiple response elements in the promoter sequence of I. indigotica 4CL gene family, and jasmonic acid had the largest number of reaction elements. The collinearity analysis showed that there was a close relationship between the 4CL gene family members of I. indigotica and A. thaliana. As revealed by qPCR results, the expression analysis of the 4CL gene family showed that 10 4CL genes had higher expression levels in the aboveground part of I. indigotica. The content assay of flavonoids in different parts of I. indigotica showed that flavonoids were mainly accumulated in the aboveground part of plants. This study provides a basis for further investigating the roles of the 4CL gene family involved in the biosynthesis of flavonoids in I. indigotica.

[Cloning and catalytic analysis of Isatis indigotica chalcone isomerase in vitro].

Chalcone isomerase is a key rate-limiting enzyme in the biosynthesis of flavonoids in higher plants, which determines the production of flavonoids in plants. In this study, RNA was extracted from different parts of Isatis indigotica and reverse-transcribed into cDNA. Specific primers with enzyme restriction sites were designed, and a chalcone isomerase gene was cloned from I. indigotica, named IiCHI. IiCHI was 756 bp in length, containing a complete open reading frame and encoding 251 amino acids. Homology analysis showed that IiCHI was closely related to CHI protein of Arabidopsis thaliana and had typical active sites of chalcone isomerase. Phylogenetic tree analysis showed that IiCHI was classified into type Ⅰ CHI clade. Recombinant prokaryotic expression vector pET28a-IiCHI was constructed and purified to obtain IiCHI recombinant protein. In vitro enzymatic analysis showed that the IiCHI protein could convert naringenin chalcone into naringenin, but could not catalyze the production of liquiritigenin by isoliquiritigenin. The results of real-time quantitative polymerase chain reaction(qPCR) showed that the expression level of IiCHI in the aboveground parts was higher than that in the underground parts and the expression level was the highest in the flowers of the aboveground parts, followed by leaves and stems, and no expression was observed in the roots and rhizomes of the underground parts. This study has confirmed the function of chalcone isomerase in I. indigotica and provided references for the biosynthesis of flavonoid components.

[Effect of ASO Blood Stasis Syndrome Serum on Vascular Endothelial Cell Injury and Regulation of Taohong Siwu Decoction on it].

OBJECTIVE: To explore the effect of arteriosclerosis obliterans (ASO) blood stasis syndrome (BSS) serum on vascular endothelial cell injury and to study the regulation of Taohong Siwu Decoction (TSD) on it. METHODS: Umbilical vein endothelial cell culture system was established. The serum endothelial cell injury model with ASO BSS was prepared. Low, medium, and high concentrations TSD containing serums were respectively added. The endothelial cell proliferation activity was observed by MTT method. Ultrastructures of endothelial cells were observed under transmission electron microscope. Changes of intracellular calcium ion concentration and the cytoskeleton were observed under laser confocal microscope. Contents of ET, NO, and transforming growth factor beta1 (TGF-beta1) in endothelial cell culture supernatant were detected by ELISA. RESULTS: In ASO BSS serum group endothelial cell proliferation activities decreased, the cell structure was obviously destroyed, calcium ion concentration increased, contents of ET, NO and TGF-beta1 increased significantly (P < 0.01), and ET/NO ratio was imbalanced. After incubating with TSD drug containing serum, endothelial cell proliferation activities and injured cell structures were obviously improved; ET, NO and TGF-beta1 levels decreased (P < 0.05, P < 0.01), ET/NO ratios approximated to the normal level. CONCLUSION: The main mechanism of TSD for treating ASO ASS lied in improving injured vascular endothelial cells and endocrine disorder.

Tomato WRKY transcriptional factor SlDRW1 is required for disease resistance against Botrytis cinerea and tolerance to oxidative stress.

WRKY proteins comprise a large family of transcription factors that play important roles in plant responses to biotic and abiotic stresses; however, only a few of tomato WRKYs have been studied for their biological functions. In the present study, we identified a Botrytis cinerea-responsive WRKY gene SlDRW1 (Solanum lycopersicumdefense-related WRKY1) from tomato. SlDRW1 is a nucleus localized protein with transactivation activity in yeast. Expression of SlDRW1 was significantly induced by B. cinerea, leading to 10-13 folds of increase than that in the mock-inoculated plants but not by Pseudomonas syringae pv. tomato (Pst) DC3000. Silencing of SlDRW1 resulted in increased severity of disease caused by B. cinerea, but did not affect the phenotype of disease caused by Pst DC3000. In addition, silencing of SlDRW1 also resulted in decreased tolerance against oxidative stress but did not affect drought stress tolerance. Furthermore, silencing of SlDRW1 attenuated defense response such as expression of defense-related genes after infection by B. cinerea. Our results demonstrate that SlDRW1 is a positive regulator of defense response in tomato against B. cinerea and oxidative stress.

[Taohong Siwu Decoction regulated functions of endothelial cells and treated arteriosclerosis obliterans: an experimental study].

OBJECTIVE: To discuss the effect of Taohong Siwu Decoction (TSD) in regulating functions of endothelial cells and treating arteriosclerosis obliterans (ASO). METHODS: The ASO model was prepared by using high-fat diet plus intimal injury. They were randomly divided into the model group (n = 10), the normal control group (n = 9), the low dose TSD group (group A, n = 12), the middle dose TSD group (group B, n = 10), and the high dose TSD group (group C, n = 9). Eight weeks after modeling, the limb blood perfusion was observed using laser Doppler flowmetry. The arterial morphology was observed using light microscope and transmission electron microscope. The number of circulating endothelial cells (CECs) was determined using Percoll density gradient centrifugation method. Serum levels of TNF-alpha, IL-1, ET-1, and NO were detected using double antibody sandwich assay of enzyme linked immunosorbent assay (ELISA). RESULTS: The ASO rat model was successfully established. Blood lipids levels significantly increased, the blood perfusion of left hind limbs significantly decreased, the number of CECs in the peripheral blood significantly increased, the arterial lumen was irregularly narrowed, the ultra-structure of vessel walls was damaged, serum levels of TNF-alpha, IL-1, and ET-1 significantly increased, and the serum level of NO significantly decreased in the model group, showing statistical difference when compared with the normal control group (P < 0.01). Compared with the model group, significant improvement in the aforesaid indices was shown in group B and C (P < 0.05, P < 0.01). CONCLUSIONS: The injury and abnormal functions of endothelial cells is an important pathological process of ASO. As an effective recipe for treating ASO, TSD could protect vascular endothelial cells and improve the secretion function of vascular endothelial cells.