Tropaeolum majus R2R3 MYB Transcription Factor TmPAP2 Functions as a Positive Regulator of Anthocyanin Biosynthesis.

Anthocyanins are an important group of water-soluble and non-toxic natural pigments with antioxidant and anti-inflammatory properties that can be found in flowers, vegetables, and fruits. Anthocyanin biosynthesis is regulated by several different types of transcription factors, including the WD40-repeat protein Transparent Testa Glabra 1 (TTG1), the bHLH transcription factor Transparent Testa 8 (TT8), Glabra3 (GL3), Enhancer of GL3 (EGL3), and the R2R3 MYB transcription factor Production of Anthocyanin Pigment 1 (PAP1), PAP2, MYB113, and MYB114, which are able to form MYB-bHLH-WD40 (MBW) complexes to regulate the expression of late biosynthesis genes (LBGs) in the anthocyanin biosynthesis pathway. Nasturtium (Tropaeolum majus) is an edible flower plant that offers many health benefits, as it contains numerous medicinally important ingredients, including anthocyanins. By a comparative examination of the possible anthocyanin biosynthesis regulator genes in nasturtium varieties with different anthocyanin contents, we found that TmPAP2, an R2R3 MYB transcription factor gene, is highly expressed in "Empress of India", a nasturtium variety with high anthocyanin content, while the expression of TmPAP2 in Arabidopsis led to the overproduction of anthocyanins. Protoplast transfection shows that TmPAP2 functions as a transcription activator; consistent with this finding, some of the biosynthesis genes in the general phenylpropanoid pathway and anthocyanin biosynthesis pathway were highly expressed in "Empress of India" and the 35S:TmPAP2 transgenic Arabidopsis plants. However, protoplast transfection indicates that TmPAP2 may not be able to form an MBW complex with TmGL3 and TmTTG1. These results suggest that TmPAP2 may function alone as a key regulator of anthocyanin biosynthesis in nasturtiums.

A new insight into the mechanism for cytosolic lipid droplet degradation in senescent leaves.

Leaf senescence involves lipid droplet (LD) degradation that produces toxic fatty acids, but little is known about how the toxic metabolites are isolated from the rest of the cellular components. Our ultramicroscopic characterization of cytosolic LD degradation in central vacuole-absent cells and central vacuole-containing cells of senescent watermelon leaves demonstrated two degradation pathways: the small vacuole-associated pathway and the central vacuole-associated pathway. This provided an insight into the subcellular mechanisms for the isolation of the fatty acids derived from LDs. The central vacuole-containing cells, including mesophyll cells and vascular parenchyma cells, adopted the central vacuole-associated pathway, indicated by the presence of LDs in the central vacuole, which is believed to play a crucial role in scavenging toxic metabolites. The central vacuole-absent intermediary cells, where senescence caused the occurrence of numerous small vacuoles, adopted the small vacuole-associated pathway, evidenced by the occurrence of LDs in the small vacuoles. The assembly of organelles, including LDs, small vacuoles, mitochondria and peroxisome-like organelles, occurred in the central vacuole-absent intermediary cell in response to leaf senescence.

Function of terahertz spectra in monitoring the decomposing process of biological macromolecules and in investigating the causes of photoinhibition.

Chlorophyll a and ß-carotene play an important role in harvesting light energy, which is used to drive photosynthesis in plants. In this study, terahertz (THz) and visible range spectra of chlorophyll a and ß-carotene and their changes under light treatment were investigated. The results show that the all THz transmission and absorption spectra of chlorophyll a and ß-carotene changed upon light treatment, with the maximum changes at 15 min of illumination indicating the greatest changes of the collective vibrational mode of chlorophyll a and ß-carotene. The absorption spectra of chlorophyll a in the visible light region decreased upon light treatment, signifying the degradation of chlorophyll a molecules. It can be inferred from these results that the THz spectra are very sensitive in monitoring the changes of the collective vibrational mode, despite the absence of changes in molecular configuration. The THz spectra can therefore be used to monitor the decomposing process of biological macromolecules; however, visible absorption spectra can only be used to monitor the breakdown extent of biological macromolecules.

Nitric oxide synthase inhibitors: a review of patents from 2011 to the present.

INTRODUCTION: Nitric oxide synthases (NOSs) are a family of enzymes that play an essential role in synthesizing nitric oxide (NO) by oxidizing l-arginine. As previously reported, NO is a significant mediator in cellular signaling pathways. It serves as a crucial regulator in insulin secretion, vascular tone, peristalsis, angiogenesis, neural development and inflammation. Due to its important role, the inhibition of these vital enzymes provides, as tools, the opportunity to gain an insight into potential therapeutic applications targeting NOSs. AREAS COVERED: This paper reviews the patent literature between 2011 and mid-2014 that specified inhibitors of NOS family members as the significant targets. Google and Baidu search engines were used to find relevant patents and clinical information using NOSs or NOS inhibitor as search terms. EXPERT OPINION: Considerable recent progress has been made in the development of NOS inhibitors with pharmacodynamic and pharmacokinetic properties, and such development is likely to continue. The patented compounds attenuated mostly embodying evidence from in vitro and in vivo trials that demonstrate good potential for future clinical human trials and industrial applications. Furthermore, new techniques such as X-ray ligand crystallographic study and structure-activity relationship were popularly utilized, which give new insights for developing novel, safe, efficient and selective NOS inhibitors.

Production and characterization of a somatic hybrid of Chinese cabbage and cabbage.

In order to broaden Chinese cabbage gene pool, we conducted interspecific somatic hybridization between Chinese cabbage (Brassica campestris, 2n=20, AA) and Cabbage (B. oleracea, 2n=18, CC). Protoplasts were isolated from 10-day-old cotyledons and hypocotyls of young seedlings, and fused by 40% polyethylene glycol (PEG). Fused cells were cultured in modified K8p liquid medium supplemented with some plant growth regulators. Fusion products were characterized by their morphological, cytological and molecular biological traits. The results showed that, a total of 35 regenerated green plants were obtained from 320 calli, the plant regeneration frequency was 10.94%, and eleven of which were survived in greenhouse. All regenerants were true hybrids as confirmed by randomly amplified polymorphic DNA (RAPD) and genomic in situ hybridization (GISH) analysis. Ploidy levels of hybrid plants were determined by chromosome counting and flow cytometry. The sum of the chromosome number (2n = 38) from the two fusion patents were found in 36.4% of regeneratns; another 36.4% had chromosomes range to 58-60; 27.2% had more chromosomes ranges to 70-76. All regenerated plants produced normal flowers. We investigated the pollen fertility and seed set after self-pollination and backcrossing with the parental species. For hybrids with chromosomes more than 38 it was possible to obtain some seeds when they after self-pollination. Within the group of hybrids with 38 chromosomes, seed set were very variable, only 0.11 seeds per pod by self-pollination, 0.23-0.76 by open-pollination, 0.02-0.04 by backcrossing with Chinese cabbage. Progeny lines obtained by self-pollination had larger leaves and leaf shapes intermediate of the parental species. Pollen fertility was gradually recovered in the first and second progenies. The backcrossing progeny lines, as a whole, exhibited morphologies were similar to Chinese cabbage. Morphological variations were observed among the somatic hybrids and their progenies.

Morphological, cytological, and molecular characterization of hybrids and their progenies derived from the somatic hybridization of Brassica campestris and Brassica oleracea.

In order to produce interspecific somatic hybrids between Brassica campestris (2n = 20, AA) and Brassica oleracea (2n = 18, CC), we isolated protoplasts from cotyledons and hypocotyls of young seedlings, and fused by 40% polyethylene glycol (PEG). Fused cells were cultured in modified K8p liquid medium supplemented with 0.2 mg/L 2,4-dichorophenoxyacetic acid (2,4-D) +0.5 mg/L 6-benzylaminopurine (6-BA)+0.1 mg/L naphthaleneacetic acid (NAA)+ 0.1 mg/L Kinetin (Kin), 0.3 mol/L sucrose and 0.3 mol/L glucose were used as osmoticum. At the eight-to ten-cell stage, divided cells were transferred to Kao's basal medium supplemented with 0.3 mol/L sucrose as carbon source and 0.1% agarose, 2 mg/L 6-BA+ 2 mg/L Zeatin (ZEA)+1 mg/L NAA+ 0.5 mg/L Kin for callus induction. After 35 days, when small calli reached 2-3 mm in diameter, calli were transferred to regeneration medium containing 5 mg/L Zeatin (ZEA) and 2 mg/L indole-3-acetic acid (IAA). After the length of the shoots reached 1-2 cm, the shoots were transferred to 1/2 MS+0.2 mg/L NAA for root induction. Morphological, cytological and molecular biological analysis methods were used for identification of somatic hybrids. The results showed that, the first cell division occurred during 2-7 days of culture. Five weeks after culture initiation, the plating efficiency attained 0.66%. Finally, the shoot regeneration frequency was 3.7%. A total of eleven regenerated plants were obtained and verified as somatic hybrids by morphological observation and flow cytometry. Cytological studies showed that all tested plants had a chromosome number of 38, the sum of both parents. Hybridity was also confirmed by randomly amplified polymorphic DNA (RAPD) and genomic in situ hybridization (GISH) analysis, indicating that these regenerated plants were all true hybrids of B. campestris and B. oleracea. All amphidiploid somatic hybrids showed low pollen fertility. Pollen fertility was gradually recovered in the first and second progenies.

Expression and purification of His-tagged flavonol synthase of Camellia sinensis from Escherichia coli.

Flavonols, a class of bioactive polyphenols present in plants, are the products of flavonol desaturation catalyzed by flavonol synthase (FLS). We cloned the cDNA coding for the enzyme FLS from Camellia sinensis (CsFLS) by end-to-end PCR followed by 5'- and 3'-RACE. The putative CsFLS had 333 amino acid residues, displayed identities to the FLSs of Arabidopsis and Ginkgo of 53% and 52.5%, respectively, and contained several conserved elements found in the 2-oxoglutarate-Fe(II)-dioxygenase superfamily. The cDNA of CsFLS was subcloned into pET28a(+) and introduced into Escherichia coli (BL21-CodonPlus-RIL). Induction with 0.1mM IPTG at low temperature (20 degrees C) led to higher amounts of CsFLS in the soluble fraction than induction at 30 degrees C. The enzyme aggregated into inclusion bodies could be rescued by denaturation with 6M urea and purification with a His. Bind purification kit. The purified protein was desalted by Amicon Ultra-15 centrifugal filter unit, and the His-tag was removed with thrombin. The finally purified protein was assayed with dihydroquercetin as substrate and the products were analyzed by HPLC. The addition of FeSO(4) to the buffers used in the CsFLS purification significantly increased the recovery of active enzyme. The CsFLS obtained in this study was found to have higher specific activity and lower K(m) than previously reported FLSs.