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In order to explore the molecular mechanisms of Populus simonii × P. nigra response to stress and screen for genes conferring resistance to Alternaria alternata, we carried out measurements of physiological and biochemical indices and transcriptomic sequence analysis of leaves of Populus simonii × P. nigra inoculated with A. alternata. The results showed that the variation trends of multiple hormone contents and enzyme activities were broadly similar at different time points, with H2O2, SA, JA, PPO, SOD, PAL and POD showing a trend of increasing and then decrease after inoculation with the pathogen. The contents of H2O2 peaked on the second day and subsequently declined. The contents of SA and JA, as well as the enzymatic activities of SOD, PAL, and POD, reached their maxima on the third day before exhibiting a downward tendency. In contrast, the activity of PPO peaked on the fourth day. Whereas ABA content continued to increase until the fifth day and CAT content decreased and then increased. We subsequently identified 14,997 differentially expressed genes (DEGs) among the transcriptomic sequences(|log2FoldChange| > 1 and FDR value < 0.05), with genes encoding members of the ERF, MYB, bZIP, and WRKY transcription factor families being differentially expressed. Gene modules that were significantly associated with the ABA, PAL, JA, and SOD activity were identified using weighted gene co-expression network analysis (WGCNA). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that these genes were mainly related to biological stress, signal transduction, cell wall, and photosynthesis. Within these modules, we also identified hub genes in the regulatory network, including GLK1/2 transcriptional activators, 14-3-3 proteins, cytosine 5 methyltransferases, and a variety of proteins associated with photosynthesis and respiration. This study showed that these hub genes, which play a pivotal role in the co-expression network, which may indicate a potential role in defense process of Populus simonii × P. nigra against A. alternata. Additionally, we analyzed the gene expression regulation and defense mechanisms of Populus simonii × P. nigra adversity stress, providing new insights into how plants respond to biological stress.

IntroductionPediococcus acidilactici CNCM I-4622 (PA) is a homofermentative Gram-positive coccus that produces lactic acid as a major metabolic by-product. However, the potential of PA to improve intestinal function and, as a result, improve production performance and quality in aged laying hens remains unclear. This study aimed to investigate the effects of PA on egg production, egg quality, intestinal health, and cecal microbiota in aged laying hens.MethodsA total of 180 Lohmann pink laying hens, aged 80 weeks, were randomly assigned to five groups and fed either a basal diet (PA0) or basal diets supplemented with PA at concentrations of 50, 100, 150, and 200 mg/kg (PA50, PA100, PA150, and PA200).ResultsCompared to the PA0 group, PA did not have a significant effect on the production performance of laying hens (p > 0.05). However, the content of diamine oxidase and the expression level of IL-8 mRNA in the PA50, P100, P150, and P200 groups were significantly reduced (p

To screen strains with high production of cold-active lipase and optimize enzyme production conditions, as well as to provide production information for the industrial development of lipase, a cold-active lipase producing strain was screened from soil samples in Mohe County, Heilongjiang Province, and identified as Serratia plymuthica by morphological identification, physiological and biochemical experiments and molecular biology. The effects of different factors such as temperature, pH, loading volume, inoculum, carbon source, nitrogen source, metal ion and inducer on the enzyme production of the strain were investigated by single-factor experiments, as well as the optimization of the addition of olive oil, peptone and loading volume by Plackett-Burman experiment, hill climbing test and response surface design. The results showed that the optimal enzyme production conditions were 20 ℃, pH7.5, loading volume 42 mL, inoculum 0.5%, 20 g/L maltose, 14 g/L peptone, 0.5 g/L MgSO4·7H2O and 46 mL/L olive oil. The lipase activity under this optimized condition was 98.05 U/mL, which was 5.85 times higher than that before optimization. The results of enzymatic properties showed that the optimum temperature of this lipase was 30 ℃, which was a low temperature lipase, and the optimum reaction pH was 7. Mg2+ could obviously promote the enzyme activity. The organic solvents methanol and ethanol obviously inhibited the enzyme activity, while n-hexane could obviously promote the enzyme activity. The conclusion can provide some theoretical basis and methodological guidance for the development and utilization of microbial resources and industrial production of low-temperature lipase.

BACKGROUND: The rice white tip nematode Aphelenchoides besseyi, a devastating nematode whose genome has not been sequenced, is distributed widely throughout almost all the rice-growing regions of the world. The aims of the present study were to define the transcriptome of A. besseyi and to identify parasite-related, mortality-related or host resistance-overcoming genes in this nematode. METHODOLOGY AND PRINCIPAL FINDINGS: Using Solexa/Illumina sequencing, we profiled the transcriptome of mixed-stage populations of A. besseyi. A total of 51,270 transcripts without gaps were produced based on high-quality clean reads. Of all the A. besseyi transcripts, 9,132 KEGG Orthology assignments were annotated. Carbohydrate-active enzymes of glycoside hydrolases (GHs), glycosyltransferases (GTs), carbohydrate esterases (CEs) and carbohydrate-binding modules (CBMs) were identified. The presence of the A. besseyi GH45 cellulase gene was verified by in situ hybridization. Given that 13 unique A. besseyi potential effector genes were identified from 41 candidate effector homologs, further studies of these homologs are merited. Finally, comparative analyses were conducted between A. besseyi contigs and Caenorhabditis elegans genes to look for orthologs of RNAi phenotypes, neuropeptides and peptidases. CONCLUSIONS AND SIGNIFICANCE: The present results provide comprehensive insight into the genetic makeup of A. besseyi. Many of this species' genes are parasite related, nematode mortality-related or necessary to overcome host resistance. The generated transcriptome dataset of A. besseyi reported here lays the foundation for further studies of the molecular mechanisms related to parasitism and facilitates the development of new control strategies for this species.

The microscopical observation and karyoltype analysis of embryo root cells of healthy Xingkai Lake pine and Xingkai Lake pine infected by Cronartium quercuum were conducted. The results showed that the dividing phase of embryo root cells decreased and the viscidity of cells in dividing phase increased when Xingkai Lake pine was infected by C. quercuum. The karyoltype changed from the contract 4A to 4B, but the number of cell chromosome and karyoltype component did not change. [ABSTRACT FROM AUTHOR]