In plants, basic leucine zipper (bZIP) proteins regulate numerous biological processes such as seed maturation, flower and vascular development, stress signalling and pathogen defence. We have carried out a genome-wide identification and analysis of 125 bZIP genes that exist in the maize genome, encoding 170 distinct bZIP proteins. This family can be divided into 11 groups according to the phylogenetic relationship among the maize bZIP proteins and those in Arabidopsis and rice. Six kinds of intron patterns (a–f) within the basic and hinge regions are defined. The additional conserved motifs have been identified and present the group specificity. Detailed three-dimensional structure analysis has been done to display the sequence conservation and potential distribution of the bZIP domain. Further, we predict the DNA-binding pattern and the dimerization property on the basis of the characteristic features in the basic and hinge regions and the leucine zipper, respectively, which supports our classification greatly and helps to classify 26 distinct subfamilies. The chromosome distribution and the genetic analysis reveal that 58 ZmbZIP genes are located in the segmental duplicate regions in the maize genome, suggesting that the segment chromosomal duplications contribute greatly to the expansion of the maize bZIP family. Across the 60 different developmental stages of 11 organs, three apparent clusters formed represent three kinds of different expression patterns among the ZmbZIP gene family in maize development. A similar but slightly different expression pattern of bZIPs in two inbred lines displays that 22 detected ZmbZIP genes might be involved in drought stress. Thirteen pairs and 143 pairs of ZmbZIP genes show strongly negative and positive correlations in the four distinct fungal infections, respectively, based on the expression profile and Pearson's correlation coefficient analysis.

BackgroundIn plant, non-specific lipid transfer proteins (nsLTPs) are small, basic proteins that have been reported to be involved in numerous biological processes such as transfer of phospholipids, reproductive development, pathogen defence and abiotic stress response. To date, only a tiny fraction of plant nsLTPs have been functionally identified, and even fewer have been identified in maize [Zea mays (Zm)].ResultsIn this study, we carried out a genome-wide analysis of nsLTP gene family in maize and identified 63 nsLTP genes, which can be divided into five types (1, 2, C, D and G). Similar intron/exon structural patterns were observed in the same type, strongly supporting their close evolutionary relationship. Gene duplication analysis indicated that both tandem and segmental duplication contribute to the diversification of this gene family. Additionally, the three-dimensional structures of representative nsLTPs were studied with homology modeling to understand their molecular functions. Gene ontology analysis was performed to obtain clues about biological function of the maize nsLTPs (ZmLTPs). The analyses of putative upstream regulatory elements showed both shared and distinct transcriptional regulation motifs of ZmLTPs, further indicating that ZmLTPs may play roles in diverse biological processes. The dynamic expression patterns of ZmLTPs family across the different developmental stages showed that several of them exhibit tissue-specific expression, indicative of their important roles in maize life cycle. Furthermore, we focused on the roles of maize nsLTPs in biotic and abiotic stress responses. Our analyses demonstrated that some ZmLTPs exhibited a delayed expression pattern after the infection of Ustilago maydis and differentially expressed under drought, salt and cold stresses, and these may be a great help for further studies to improve the stress resistance and tolerance in maize breeding.ConclusionsOur results provide new insights into the phylogenetic relationships and characteristic functions of maize nsLTPs and will be useful in studies aimed at revealing the global regulatory network in maize development and stress responses, thereby contributing to the maize molecular breeding with enhanced quality traits.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-014-0281-8) contains supplementary material, which is available to authorized users.

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Background This study aimed to explore the effect of long non-coding RNA (LncRNA) H19 on the proliferation and invasion of lung carcinoma cells A549, and to determine its molecular targets. Methods A549 cells were with either LncRNA H19 or LncRNA H19 shRNA, and the expression levels of LncRNA H19 were evaluated by quantitative real-time PCR (RT-PCR). We measured cell proliferation using the CCK-8 assay, cell counting assays, and colony formation assay in response to shLncRNA H19-2. Cell migration and invasion were assessed by wound healing assay and Transwell assay, respectively. The mRNA and protein expression levels of E-cadherin, N-cadherin, and vimentin were determined by RT-PCR and western blot, respectively. Results The three LncRNA H19 shRNAs used in our study significantly reduced the expression levels of LncRNA H19 in A549 cells ( P <0.05). Moreover, LncRNA H19 shRNA 2 (shLncRNA-2) was the most potent inhibitor of LncRNA H19 expression, and was selected for further experimentation. Transfection with shLncRNA H19-2 significantly decreased the proliferation, migration, and invasion of A549 cells, while overexpression of LncRNA H19 had the opposite effect in these cells ( P <0.05). In response to shLncRNA H19-2, the expression levels of E-cadherin were notably elevated ( P <0.05), while the expression levels of N-cadherin and vimentin were decreased ( P <0.05). In contrast, overexpression of LncRNA H19 induced the expression of E-cadherin, and blocked the expression of N-cadherin, and vimentin ( P <0.05). Conclusion Our results suggest that LncRNA H19 mediates the proliferation and invasion of lung cancer cells via upregulation of N-cadherin and vimentin, and downregulation of E-cadherin.

Increasing evidence supports that microRNA (miRNA) plays a significant functional role in cancer progression by directly regulating respective targets. In this study, the expression levels of miR-105-1 and its target gene were analyzed using genes microarray and hierarchical clustering analysis followed by validation with quantitative RT-PCR in hepatocellular carcinoma (HCC) and normal liver tissues. We examined the expression of nuclear receptor coactivator 1 (NCOA1), the potential target gene of miR-105-1, following the transfection of miR-105-1 mimics or inhibitors. Our results showed that miR-105-1 was downregulated in HCC tissues when compared with normal liver tissues and patients with lower miR-105-1 expression had shorter overall survival (OS) and progression free survival (PFS). Moreover, NCOA1 was confirmed to be a direct target of miR-105-1. Furthermore, concomitant high expression of NCOA1 and low expression of miR-105-1 correlated with a shorter median OS and PFS in HCC patients. In conclusion, our results provide the first evidence that NCOA1 is a direct target of miR-105-1 suggesting that NCOA1 and miR-105-1 may have potential prognostic value and may be useful as tumor biomarkers for the diagnosis of HCC patients.