Cancer remains one of the most lethal diseases worldwide. There is an urgent need for new drugs with novel modes of action and thus considerable research has been conducted for new anticancer drugs from natural sources, especially plants, microbes and marine organisms. Marine populations represent reservoirs of novel bioactive metabolites with diverse groups of chemical structures. This review highlights the impact of marine organisms, with particular emphasis on marine plants, algae, bacteria, actinomycetes, fungi, sponges and soft corals. Anti-cancer effects of marine natural products in in vitro and in vivo studies were first introduced; their activity in the prevention of tumor formation and the related compound-induced apoptosis and cytotoxicities were tackled. The possible molecular mechanisms behind the biological effects are also presented. The review highlights the diversity of marine organisms, novel chemical structures, and chemical property space. Finally, therapeutic strategies and the present use of marine-derived components, its future direction and limitations are discussed.

The plant-specific NAC (NAM, ATAF1/2, and CUC2) transcription factors (TFs) play important roles in plant growth, development, and stress responses. However, the precise role of NAC TFs in relation to fruit ripening is poorly understood. In this study, six NAC genes, designated MaNAC1–MaNAC6, were isolated and characterized from banana fruit. Subcellular localization showed that MaNAC1–MaNAC5 proteins localized preferentially to the nucleus, while MaNAC6 was distributed throughout the entire cell. A transactivation assay in yeast demonstrated that MaNAC4 and MaNAC6, as well as their C-terminal regions, possessed trans-activation activity. Gene expression profiles in fruit with four different ripening characteristics, including natural, ethylene-induced, 1-methylcyclopropene (1-MCP)-delayed, and a combination of 1-MCP with ethylene treatment, revealed that the MaNAC genes were differentially expressed in peel and pulp during post-harvest ripening. MaNAC1 and MaNAC2 were apparently upregulated by ethylene in peel and pulp, consistent with the increase in ethylene production. In contrast, MaNAC3 in peel and pulp and MaNAC5 in peel were constitutively expressed, and transcripts of MaNAC4 in peel and pulp and MaNAC6 in peel decreased, while MaNAC5 or MaNAC6 in pulp increased slightly during fruit ripening. Furthermore, the MaNAC2 promoter was activated after ethylene application, further enhancing the involvement of MaNAC2 in fruit ripening. More importantly, yeast two-hybrid and bimolecular fluorescence complementation analyses confirmed that MaNAC1/2 physically interacted with a downstream component of ethylene signalling, ethylene insensitive 3 (EIN3)-like protein, termed MaEIL5, which was downregulated during ripening. Taken together, these results suggest that MaNACs such as MaNAC1/MaNAC2, may be involved in banana fruit ripening via interaction with ethylene signalling components.

BackgroundTreatment of plants with HrpNEa, a protein of harpin group produced by Gram-negative plant pathogenic bacteria, induces plant resistance to insect herbivores, including the green peach aphid Myzus persicae, a generalist phloem-feeding insect. Under attacks by phloem-feeding insects, plants defend themselves using the phloem-based defense mechanism, which is supposed to involve the phloem protein 2 (PP2), one of the most abundant proteins in the phloem sap. The purpose of this study was to obtain genetic evidence for the function of the Arabidopsis thaliana (Arabidopsis) PP2-encoding gene AtPP2-A1 in resistance to M. persicae when the plant was treated with HrpNEa and after the plant was transformed with AtPP2-A1.ResultsThe electrical penetration graph technique was used to visualize the phloem-feeding activities of apterous agamic M. persicae females on leaves of Arabidopsis plants treated with HrpNEa and an inactive protein control, respectively. A repression of phloem feeding was induced by HrpNEa in wild-type (WT) Arabidopsis but not in atpp2-a1/E/142, the plant mutant that had a defect in the AtPP2-A1 gene, the most HrpNEa-responsive of 30 AtPP2 genes. In WT rather than atpp2-a1/E/142, the deterrent effect of HrpNEa treatment on the phloem-feeding activity accompanied an enhancement of AtPP2-A1 expression. In PP2OETAt (AtPP2-A1-overexpression transgenic Arabidopsis thaliana) plants, abundant amounts of the AtPP2-A1 gene transcript were detected in different organs, including leaves, stems, calyces, and petals. All these organs had a deterrent effect on the phloem-feeding activity compared with the same organs of the transgenic control plant. When a large-scale aphid population was monitored for 24 hours, there was a significant decrease in the number of aphids that colonized leaves of HrpNEa-treated WT and PP2OETAt plants, respectively, compared with control plants.ConclusionsThe repression in phloem-feeding activities of M. persicae as a result of AtPP2-A1 overexpression, and as a deterrent effect of HrpNEa treatment in WT Arabidopsis rather than the atpp2-a1/E/142 mutant suggest that AtPP2-A1 plays a role in plant resistance to the insect, particularly at the phloem-feeding stage. The accompanied change of aphid population in leaf colonies suggests that the function of AtPP2-A1 is related to colonization of the plant.

No abstract

Here, we describe the first in vivo application of non-toxic, cell-permeable synthetic ligands to regulate signal transduction in transgenic mice expressing a conditional receptor. Using this system, we show that the Fas pathway is restricted to double-positive thymocytes in vivo, consistent with recent in vitro findings with thymocytes. This method promises to be more useful not only for developmental studies involving cell ablation, but also for studies involving the regulation of a wide variety of signaling molecules.

No abstract

In the past few years, the immobilization of biomolecules on hybrid nanoflowers and metal–organic frameworks (MOFs) via self-assembly synthesis has received much attention due to its superior advantages.

Harpin proteins from plant pathogenic bacteria can stimulate hypersensitive cell death (HCD), drought tolerance, defence responses against pathogens and insects in plants, as well as enhance plant growth. Recently, we identified nine functional fragments of HpaG;Xooc, a harpin protein from Xanthomonas oryzae pv.oryzicola, the pathogen that causes bacterial leaf streak in rice. Fragments HpaG;1-94'HpaG;10-42, and HpaG;62-138, which contain the HpaG;Xooc regions of the amino acid sequence as indicated by the number spans, exceed the parent protein in promoting growth, pathogen defence and HCD in plants. Here we report improved productivity and biochemical properties of green tea (Camellia sinensis) in response to the fragments tested in comparison with HpaG;Xooc and an inactive protein control. Field tests suggested that the four proteins markedly increased the growth and yield of green tea, and increased the leaf content of tea catechols, a group of compounds that have relevance in the prevention and treatment of human diseases. In particular, HpaG;1-94 was more active than HpaG;Xooc in expediting the growth of juvenile buds and leaves used as green tea material and increased the catechol content of processed teas. When tea shrubs were treated with HpaH;Xooc and HpaG;1-94 compared with a control, green tea yields were over 55% and 39% greater, and leaf catechols were increased by more than 64% and 72%, respectively. The expression of three homologues of the expansin genes, which regulate plant cell growth, and the CsCHS gene encoding a tea chalcone synthase, which critically regulates the biosynthesis of catechols, were induced in germinal leaves of tea plants following treatment with HpaG;1-94 or HpaG;Xooc. Higher levels of gene expression were induced by the application of HpaG;1-94 than HpaG;Xooc. Our results suggest that the harpin protein, especially the functional fragment HpaG;1-94, can be used to effectively increase the yield and improve the biochemical properties of green tea, a drink with medicinal properties.