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Key message : Over-expression of SlJA2 decreased the accumulation of SA, which resulted in significant physiological and gene expression changes in transgenic tobacco plants, leading to the decreased heat tolerance of transgenic tobacco. Abstract: NAC family, the largest transcription factors in plants, responses to different environmental stimuli. Here, we isolated a typical NAC transcription factor ( SlJA2) from tomato and got transgenic tobacco with SlJA2 over-expression. Expression of SlJA2 was induced by heat stress (42 °C), chilling stress (4 °C), drought stress, osmotic stress, abscisic acid, and salicylic acid. Over-expression of SlJA2 decreased the accumulation of salicylic acid by regulating expression of salicylic acid degradation gene under heat stress. Compared to WT plants, stomatal apertures and water loss increased in transgenic plants, and the damage of photosynthetic apparatus and chlorophyll breakdown were more serious in transgenic plants under heat stress. Meanwhile, more HO and O were accumulated transgenic plants and proline synthesis was restricted, which resulted in more serious oxidative damage compared to WT. qRT-PCR analysis showed that over-expression of SlJA2 could down-regulate genes involved in reactive oxygen species scavenging, proline biosynthesis, and response to heat stress. All the above results indicated that SlJA2 may be a negative regulator responded to plant's heat tolerance. Thus, this study provides new insight into roles of NAC family member in plant response to abiotic stress. [ABSTRACT FROM AUTHOR]

Hantaviruses infect human endothelial cells (ECs) and are known to cause vascular-permeability-based diseases, including hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). The αvβ3 integrins, which are highly expressed on the surface of ECs, serve as hantavirus receptors. Specifically, the β3 integrin and vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) form a functional complex and interact with each other. Signaling through this complex causes cytoskeletal reorganization, which is one of the most important mechanisms underlying hyperpermeability. In this study, we show that VEGF dramatically enhances Hantaan virus (HTNV)-directed permeability and increases the reorganization of the cytoskeleton and the disruption of junctional organizations in an EC monolayer at 3 days postinfection. HTNV infection reduced the effect of VEGF on adhesion, migration, and the upregulation of β3 expression, but the infection alone upregulated the expression of β3 and VEGFR2. These results indicate that in addition to its role in blocking β3 integrin activation as reported previously, HTNV blocks the function of the complex of VEGFR2 and β3 integrin, and the dysfunction of the complex may contribute to cytoskeletal reorganization in an HTNV-directed hyperpermeability response to VEGF. [ABSTRACT FROM AUTHOR]

In plants heme containing cytochrome P450 (P450) is a superfamily of monooxygenases that catalyze the addition of one oxygen atom from O into a substrate, with a substantial reduction of the other atom to water. The function of P450 families is attributed to chemical defense mechanism under terrestrial environmental conditions; several are involved in secondary and hormone metabolism. However, the evolutionary relationships of P450 genes in Panax ginseng remain largely unknown. In the present study, data mining methods were implemented and 116 novel putative P450 genes were identified from Expressed Sequence Tags (ESTs) of a ginseng database. These genes were classified into four clans and 22 families by sequence similarity conducted at amino acid level. The representative putative P450 sequences of P. ginseng and known P450 family from other plants were used to construct a phylogenetic tree. By comparing with other genomes, we found that most of the P450 genes from P. ginseng can be found in other dicot species. Depending on P450 family functions, seven P450 genes were selected, and for that organ specific expression, abiotic, and biotic studies were performed by quantitative reverse transcriptase-polymerase chain reaction. Different genes were found to be expressed differently in different organs. Biotic stress and abiotic stress transcript level was regulated diversely, and upregulation of P450 genes indicated the involvement of certain genes under stress conditions. The upregulation of the P450 genes under methyl jasmonate and fungal stress justifies the involvement of specific genes in secondary metabolite biosynthesis. Our results provide a foundation for further elucidating the actual function and role of P450 involved in various biochemical pathways in P. ginseng. [ABSTRACT FROM AUTHOR]

Epigenetic regulation in insects may have effects on diverse biological processes. Here we survey the methylome of a model insect, the silkworm Bombyx mori, at single-base resolution using Illumina high-throughput bisulfite sequencing (MethylC-Seq). We conservatively estimate that 0.11% of genomic cytosines are methylcytosines, all of which probably occur in CG dinucleotides. CG methylation is substantially enriched in gene bodies and is positively correlated with gene expression levels, suggesting it has a positive role in gene transcription. We find that transposable elements, promoters and ribosomal DNAs are hypomethylated, but in contrast, genomic loci matching small RNAs in gene bodies are densely methylated. This work contributes to our understanding of epigenetics in insects, and in contrast to previous studies of the highly methylated genomes of Arabidopsis and human, demonstrates a strategy for sequencing the epigenomes of organisms such as insects that have low levels of methylation. [ABSTRACT FROM AUTHOR]