ABSTRACT. Calreticulin proteins play essential roles in regulating various metabolic processes and in molecular signal transduction in animals and plants. Using homologous PCR, we screened a cDNA library of the wheat resistance gene Yr5 from a near-isogenic line in the susceptible common wheat variety Taichung 29, which was inoculated with an incompatible race CYR32 of Puccinia striiformis. We isolated a novel full-length cDNA encoding calreticulin protein, which we named TaCRT1. Sequence analyses indicated that TaCRT1 contains an open reading frame of 1287 bp in length; it was deduced to encode 428 amino acids. Clustering analysis showed that TaCRT1 belongs to group III of the calreticulin protein family. Semi-quantitative RT-PCR was used to analyze expression profiles of the isolated gene under biotic and abiotic stresses. Expression of TaCRT1 was suppressed by exogenous application of phytohormones, such as abscisic acid and methyl jasmonate, and by dehydration; but it was induced by CYR32 infection and cold treatment. Based on the expression patterns, ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 10 (4): 3576-3585 (2011) TaCRT1 in plant defense and stress resistance in wheat 3577we propose that TaCRT1 participates in regulatory processes involved in defense responses and stress resistance in wheat.

Dendrobium catenatum has become a rare and endangered medicinal plant due to habitat loss in China. As one of the most important and largest transcription factors, WRKY plays a critical role in response to abiotic stresses in plants. However, little is known regarding the functions of the WRKY family in D. catenatum. In this study, a total of 62 WRKY genes were identified from the D. catenatum genome. Phylogenetic analysis revealed that DcWRKY proteins could be divided into three groups, a division supported by the conserved motif compositions and intron/exon structures. DcWRKY gene expression and specific responses under drought, heat, cold and salt stresses were analyzed through RNA-seq data and RT-qPCR assay. The results showed that these genes had tissue-specificity and displayed different expression patterns in response to abiotic stresses. The expression levels of DcWRKY22, DcWRKY36 and DcWRKY45 were up-regulated by drought stress. Meanwhile, DcWRKY22 was highly induced by heat in roots, and DcWRKY45 was significantly induced by cold stress in leaves. Furthermore, DcWRKY27 in roots and DcWRKY58 in leaves were extremely induced under salt treatment. Finally, we found that all the five genes may function in ABA- and SA-dependent manners. This study identified candidate WRKY genes with possible roles in abiotic stress and these findings not only contribute to our understanding of WRKY family genes, but also provide valuable information for stress resistance development in D. catenatum.

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BackgroundAccumulating data support that regular physical activity potentially inhibits chronic colitis, a risk factor for colitis-associated cancer (CAC). However, possible effects of physical activity on CAC and the underlying mechanisms remain poorly understood.MethodsA pretreatment of swimming on azoxymethane/dextran sodium sulfate (AOM/DSS)-induced CAC mice was implemented to determine its protective effect. Inflammation and tumorigenesis were assessed using colorectums from C57BL/6 mice. In order to determine how swimming alters colonic lipid metabolism and gene expression, a comparative analysis was conducted. Meanwhile, alterations in intestinal microbiota and short-chain fatty acids (SCFAs) were detected and analyzed. Finally, an integration analysis of colonic lipid metabolism with gene expression and intestinal microbiota was performed respectively.ResultSwimming pretreatment relieved bowel inflammation and minimized tumor formation. We demonstrated that prostaglandin E2 (PGE2)/PGE2 receptor 2 subtype (EP2) signaling as a potential regulatory target for swimming induces colonic lipid metabolites. Swimming-induced genera, Erysipelatoclostridium, Parabacteroides, Bacteroides, and Rikenellaceae_RC9_gut_group, induced intestinal SCFAs and affected the function of colonic lipid metabolites enriched in glycerophospholipid metabolism and choline metabolism in cancer.ConclusionAccording to our experiments, swimming pretreatment can protect mice from CAC by intervention in the possible link between colonic lipid metabolites and PGE2/EP2 signaling. Further, swimming-induced genera and probiotics promoted glycerophospholipid metabolism and choline metabolism in cancer, the major constituents of colonic lipid metabolites, and increased SCFAs, which were also important mechanisms for the anti-inflammatory and anti-tumorigenic effects of swimming.