Genome-wide identification and characterization of the WOX gene family in Brassica juncea / 生物工程学报

The WUSCHEL related-homeobox (WOX) family is one of the plant-specific transcription factor families, playing important roles in plant growth and development. In this study, 51 WOX gene family members were identified from the genome data of Brassica juncea by searching and screening with HUMMER, Smart and other software. Their protein molecular weight, amino acids numbers, and isoelectric point were analyzed by using Expasy online software. Furthermore, bioinformatics software was used to systematically analyze the evolutionary relationship, conservative region, and gene structure of the WOX gene family. The mustard WOX gene family was divided into three subfamilies: ancient clade, intermediate clade, and WUS clade/modern clade. Structural analysis showed that the type, organization form and gene structure of the conservative domain of WOX transcription factor family members in the same subfamily were highly consistent, while there was a certain diversity among different subfamilies. 51 WOX genes are distributed unevenly on 18 chromosomes of mustard. Most of the promoters of these genes contain cis acting elements related to light, hormone and abiotic stress. Using transcriptome data and real-time fluorescence quantitative PCR (qRT-PCR) analysis, it was found that the expression of mustard WOX gene was spatio-temporal specific, among which BjuWOX25, BjuWOX33, and BjuWOX49 might play an important role in the development of silique, and BjuWOX10, BjuWOX32, and BjuWOX11, BjuWOX23 respectively might play an important role in the response to drought and high temperature stresses. The above results may facilitate the functional study of mustard WOX gene family.

Identification and analysis of the TALE transcription factor family in radish / 生物工程学报

Three-amino acid loop extension (TALE) transcription factors play important roles in plant growth and cell differentiation. There are plenty of studies on TALE transcription factors in several model plants, but not in radish (Raphanus sativas). A genome-wide bioinformatics analysis identified 33 TALE family genes in the Xiang-Ya-Bai (XYB) radish, These genes, are distributed on nine chromosomes and all contain 4-6 exons. The 33 TALE genes in radish showed a co-linearity relationship with the 17 homologous genes in Arabidopsis thaliana. Moreover, a large number of stress response cis-elements were found in the promoter regions of these genes. Expression analysis showed that four genes in the BELL subfamily were highly expressed in roots, and two genes in the KNOX subfamily were highly expressed in shoots of bolting plants and callus. All radish TALE genes contain sequences encoding the conserved HOX domain, except for the gene RSA10037940, which is homologous to Arabidopsis KNATM. The deduced 3D structures of the TALE proteins irrespective of subtypes are highly similar. All the encoded proteins were weakly acidic and hydrophilic. The radish TALE gene family is relatively evolutionarily conserved, which was consistent with results from Arabidopsis, but quite different from that of rice. This study provides important clues for studying the biological functions of TALE transcription factors in radish.

Inhibitory effect of small interference RNA targeting hypoxia-inducible factor 1 alpha nanospheres on human esophageal squamous carcinoma TE-1 cell growth / 中国组织工程研究

BACKGROUND: Nanosphere, an ideal nonviral gene delivery vector, is not excellence of immunogenicity and oncogenicity. Nanotechnology and gene interference are used to block hypoxia-inducible factor 1 alpha (HIF-1α) expression in esophageal squamous carcinoma tissue and decrease tolerance of malignant cells to chemotherapeutics. Theoretically, they become effective methods to inhibit malignant cell growth of esophageal squamous carcinoma. OBJECTIVE: To study the inhibitory effect of small interference RNA targeting HIF-1α (siRNA-HIF-1α) nanospheres on human esophageal squamous cancer TE-1 cell growth. DESIGN, TIME AND SETTING: Based on in vitro cultured esophageal squamous cancer TE-1 cells, a completely randomized controlled study was performed at the Central Laboratory, the Third Hospital Affiliated to Sun Yat-sen University from January 2007 to December 2008. MATERIALS: siRNA-HIF-1α was synthesized by Shanghai Bioengineering Company; siRNA-HIF-1α nanospheres were prepared using solvent evaporation technique; human esophageal squamous cancer TE cell strain was provided by Shanghai Cell Bank of the Chinese Academy of Sciences. METHODS: TE-1 cells cultured in vitro were assigned into four groups: saline, gene-free nanospheres, siRNA-HIF-1α, and siRNA-HIF-1α nanospheres groups. MAIN OUTCOME MEASURES: HIF-1α mRNA expression was detected by RT-PCR; HIF-1α protein expression was detected by Western blot; apoptosis of TE-1 cells was determined by flow cytometry; TE-1 cell growth was examined by MTT. RESULTS: At 72 hours after treatment, both HIF-1α mRNA expression and HIF-1α protein expression in the siRNA-HIF-1α nanospheres group were significantly less than other three groups (P < 0.01), but apoptotic rate was significantly greater than other three groups (P < 0.01). TE-1 cell growth was remarkably inhibited in the siRNA-HIF-1α nanospheres group, which was significantly different compared with other three groups (P < 0.01).CONCLUSION: siRNA-HIF-1α nanospheres can specifically reduce both HIF-1α mRNA and HIF-1α protein expressions in esophageal squamous carcinoma TE-1 cells, significantly increase tumor cell apoptosis, and remarkably inhibit TE-1 cell growth.