Cu-Electrocatalytic Diazidation of Alkenes at ppm Catalyst Loading.

The 1,2-diamine motif is prevalent in natural products, small-molecule pharmaceuticals, and catalysts for asymmetric synthesis. Transition metal catalyzed alkene diazidation has evolved to be an attractive strategy to access vicinal primary diamines but remains challenging, especially for practical applications, due to the restriction to a certain type of olefins, the frequent use of chemical oxidants, and the requirement for high loadings of metal catalysts (1 mol % or above). Herein we report a scalable Cu-electrocatalytic alkene diazidation reaction with 0.02 mol % (200 ppm) of copper(II) acetylacetonate as the precatalyst without exogenous ligands. In addition to its use of low catalyst loading, the electrocatalytic method is scalable, compatible with a broad range of functional groups, and applicable to the diazidation of α,ß-unsaturated carbonyl compounds and mono-, di-, tri-, and tetrasubstituted unactivated alkenes.

Genome-wide identification of Tomato Golden 2-Like transcription factors and abiotic stress related members screening.

BACKGROUND: Golden 2-Like (G2-like) transcription factors play an important role in plant development. However, the roles of these G2-like regulatory genes in response to abiotic stresses in tomato are not well understood. RESULTS: In this study, we identified 66 putative G2-like genes in tomato (Solanum lycopersicum) and classified them into 5 groups (I to V) according to gene structure, motif composition and phylogenetic analysis. The G2-like genes were unevenly distributed across all 12 chromosomes. There were nine pairs of duplicated gene segments and four tandem duplicated SlGlk genes. Analysis of the cis-regulatory elements (CREs) showed that the promoter regions of SlGlks contain many kinds of stress- and hormone-related CREs. Based on RNA-seq, SlGlks were expressed in response to three abiotic stresses. Thirty-six differentially expressed SlGlks were identified; these genes have multiple functions according to Gene Ontology (GO) analysis and are enriched mainly in the zeatin biosynthesis pathway. Further studies exhibited that silencing SlGlk16 in tomato would reduce drought stress tolerance by earlier wilted, lower superoxide dismutase (SOD), peroxidase (POD) activities, less Pro contents and more MDA contents. CONCLUSIONS: Overall, the results of this study provide comprehensive information on G2-like transcription factors and G2-like genes that may be expressed in response to abiotic stresses.

The α-Subunit of the Chloroplast ATP Synthase of Tomato Reinforces Resistance to Gray Mold and Broad-Spectrum Resistance in Transgenic Tobacco.

Chloroplast ATP synthase (cpATPase) is responsible for ATP production during photosynthesis. Our previous studies showed that the cpATPase CF1 α subunit (AtpA) is a key protein involved in Clonostachys rosea-induced resistance to the fungus Botrytis cinerea in tomato. Here, we show that expression of the tomato atpA gene was upregulated by B. cinerea and Clonostachys rosea. The tomato atpA gene was then isolated, and transgenic tobacco lines were obtained. Compared with untransformed plants, atpA-overexpressing tobacco showed increased resistance to B. cinerea, characterized by reduced disease incidence, defense-associated hypersensitive response-like reactions, balanced reactive oxygen species, alleviated damage to the chloroplast ultrastructure of leaf cells, elevated levels of ATP content and cpATPase activity, and enhanced expression of genes related to carbon metabolism, photosynthesis, and defense. Incremental Ca2+ efflux and steady H+ efflux were observed in transgenic tobacco after inoculation with B. cinerea. In addition, overexpression of atpA conferred enhanced tolerance to salinity and resistance to the fungus Cladosporium fulvum. Thus, AtpA is a key regulator that links signaling to cellular redox homeostasis, ATP biosynthesis, and gene expression of resistance traits to modulate immunity to pathogen infection and provides broad-spectrum resistance in plants in the process.

Transcriptome Analysis of the Cf-12-Mediated Resistance Response to Cladosporium fulvum in Tomato.

Cf-12 is an effective gene for resisting tomato leaf mold disease caused by Cladosporium fulvum (C. fulvum). Unlike many other Cf genes such as Cf-2, Cf-4, Cf-5, and Cf-9, no physiological races of C. fulvum that are virulent to Cf-12 carrying plant lines have been identified. In order to better understand the molecular mechanism of Cf-12 gene resistance response, RNA-Seq was used to analyze the transcriptome changes at three different stages of C. fulvum infection (0, 4, and 8 days post infection [dpi]). A total of 9100 differentially expressed genes (DEGs) between 4 and 0 dpi, 8643 DEGs between 8 and 0 dpi and 2547 DEGs between 8 and 4 dpi were identified. In addition, we found that 736 DEGs shared among the above three groups, suggesting the presence of a common core of DEGs in response to C. fulvum infection. These DEGs were significantly enriched in defense-signaling pathways such as the calcium dependent protein kinases pathway and the jasmonic acid signaling pathway. Additionally, we found that many transcription factor genes were among the DEGs, indicating that transcription factors play an important role in C. fulvum defense response. Our study provides new insight on the molecular mechanism of Cf resistance to C. fulvum, especially the unique features of Cf-12 in responding to C. fulvum infection.

[Investigation in vivo of effect of ultrasound-mediated microbubble destruction on entrance of feridex into the aortal wall].

OBJECTIVE: To explore feasibility for entrance of the contrast agent Sonovue and Feridex into the aortal wall. METHODS: 17 male Japanese giant ears rabbits (common grade), including 11 atherosclerosis (AS) animal models fed with food containing high-content lipid and normal animals fed with common food as control. Respectively, 10 animals in the AS group and 6 animals in the normal group were selected in a random way to undergo ultrasound-mediated microbubble destruction (UMMD) and no ultrasound-mediated microbubble destruction (-UMMD) half and half. One animal was administrated with double doses of Feridex. After general anesthesia, MR plain scan and intravenous injection of Feridex 100 micromol Fe/kg, immediately ultrasound focused on the front wall of the aortic arch, which underwent UMMD at the pressure of 3.5 Mpa with MI1.2 while 10 ml solution (Sonovue + normal saline)was injected intravenously at the speed of 0.5 ml/min FOR 20 min. 3T magnetic resonance (MR) was performed with a moderately T2* weighted gradient sequence. Enhanced scan were performed for 1 h, 24 h, 48 h, 72 h and after killing the animal. then the specimen were delivered to conduct optical and electronic microscope examination. Variance test for the re-measured data was adopted to verify the data obtained in every group. RESULTS: The effect of UMMD group on SPIO particles entrance into the aortal wall is of marked significance (P = 0.0004) statistically. The effect of UMMD on distribution in the vessel wall is of statistical significance (P = 0.01), more particles in the dventitia. Gas or microbubbles were found to enter into the intima, media of the aorta, and verified by Oil Red O staining. After staining the findings of iron particle in the cell and out of the cell are different. CONCLUSIONS: UMMD may facilitate entrance of those SPIO particles with a bigger diameter and microbubbles into the aortal wall. This discovery may provide a new solution for penetration of complex macromolecule probes and gene-carried drug through the tunica intima of the aorta.