A plant‐traits approach to assessing the success of alien weed species in irrigated Mediterranean orchards

In addition to their impact on natural habitats, invasive alien plants can have a significant negative effect on agricultural systems and cause economic losses. Flood‐irrigated orchards in the Mediterranean Basin are vulnerable to the invasion of alien weeds, primarily because of the traditional management practices used in the orchards, which are characterized by high soil moisture during the dry summer period, nutrient availability and high levels of disturbance. This study sought to determine whether their biological traits can explain the success of alien weed species. To answer this question, 408 floristic relevés were conducted in 136 flood‐irrigated orchards on the Plains of Lleida (Catalonia, NE of Spain). Richness and cover of native and alien weeds were compared. Furthermore, a set of biological traits were compared between successful and non‐successful weeds for the whole data and separately between native and alien weeds using logistic regression and classification trees. In flood‐irrigated orchards, alien species covered most of their area, even though the richness of alien species was lower than that of the native species. The most important species were C4 species with seeds dispersed by water, and on the other hand, rosulate and caespitose‐reptant hemicryptophytes with long flowering period. Most of these traits fitted with those of the invasive alien weeds, which were mostly C4 species with seeds dispersed by water. Perennial life form characterized successful native weeds. In this study, we discuss how the traditional management of flood irrigation in fruit‐tree orchards favours invasive alien weeds that have specific traits, acting as a reservoir for the spread of alien weeds into other crops and surrounding riparian habitats. We also propose changing management practices in order to avoid the selection of alien weeds and to promote native species.     

A novel multifunctional cellulolytic enzyme screened from metagenomic resources representing ruminal bacteria

Metagenomic resources representing ruminal bacteria were screened for novel exocellulases using a robotic, high-throughput screening system, the novel CelEx-BR12 gene was identified and the predicted CelEx-BR12 protein was characterized. The CelEx-BR12 gene had an open reading frame (ORF) of 1140 base pairs that encoded a 380-amino-acid-protein with a predicted molecular mass of 41.8 kDa. The amino acid sequence was 83% identical to that of a family 5 glycosyl hydrolase from Prevotella ruminicola 23. Codon-optimized CelEx-BR12 was overexpressed in Escherichia coli and purified using Ni–NTA affinity chromatography. The Michaelis–Menten constant (K_m value) and maximal reaction velocity (V_max values) for exocellulase activity were 12.92 μM and 1.55 × 10⁻⁴ μmol min⁻¹, respectively, and the enzyme was optimally active at pH 5.0 and 37 °C. Multifunctional activities were observed against fluorogenic and natural glycosides, such as 4-methylumbelliferyl-β-d-cellobioside (0.3 U mg⁻¹), CMC (105.9 U mg⁻¹), birch wood xylan (132.3 U mg⁻¹), oat spelt xylan (67.9 U mg⁻¹), and 2-hydroxyethyl-cellulose (26.3 U mg⁻¹). Based on these findings, we believe that CelEx-BR12 is an efficient multifunctional enzyme as endocellulase/exocellulase/xylanase activities that may prove useful for biotechnological applications.     

SHORT Syndrome with Partial Lipodystrophy Due to Impaired Phosphatidylinositol 3 Kinase Signaling

The phosphatidylinositol 3 kinase (PI3K) pathway regulates fundamental cellular processes such as metabolism, proliferation, and survival. A central component in this pathway is the p85α regulatory subunit, encoded by PIK3R1. Using whole-exome sequencing, we identified a heterozygous PIK3R1 mutation (c.1945C>T [p.Arg649Trp]) in two unrelated families affected by partial lipodystrophy, low body mass index, short stature, progeroid face, and Rieger anomaly (SHORT syndrome). This mutation led to impaired interaction between p85α and IRS-1 and reduced AKT-mediated insulin signaling in fibroblasts from affected subjects and in reconstituted Pik3r1-knockout preadipocytes. Normal PI3K activity is critical for adipose differentiation and insulin signaling; the mutated PIK3R1 therefore provides a unique link among lipodystrophy, growth, and insulin signaling.     

Field and laboratory studies on the life-cycle, growth and feeding preference in the hairy snail Trochulus hispidus (L., 1758) (Gastropoda: Pulmonata: Hygromiidae)

For the first time the life cycle of the common land snail Trochulus hispidus was completely described in Central Europe (Poland). This is a semelparous species predominantly with an annual life cycle and the reproductive period lasting from April till October. The first young snails hatch in spring, grow rapidly in summer and reach ca. 4 whorls until winter. In spring of the next year they mature and reproduce. After that they die. There is hardly any growth from late autumn till early spring. The average proportional growth rate is ca. 0.3 whorl/month in the wild. The fastest growth is present in the youngest snails and then gradually decreases over the course of their age. Laboratory and field observations allowed for establishing the following life cycle parameters: eggs calcified, almost spherical, ca. 1.5 mm, laid in spring and summer in batches of between 1 and 47. Time to hatching is 6–24 days, hatching is asynchronous; newly-hatched snails have approximately 1.5 whorls. Analysis of food preferences revealed, that T. hispidus tends to restrict its diet during the life. Generally the youngest snails equally consumed leaves of all four tree species offered (Fraxinus excelsior, Acer pseudoplatanus, Tilia cordata and A. platanoides) whereas adults preferred F. excelsior over A. pseudoplatanus and A. platanoides.     

Synthesis and acrosin inhibitory activities of 5-phenyl-1H-pyrazole-3-carboxylic acid amide derivatives

A series of novel 5-phenyl-1H-pyrazole-3-carboxylic acid amide derivatives were designed, synthesized, and their acrosin inhibitory activities in vitro were evaluated. The results of the acrosin inhibitory activity showed that all target compounds were more potent than control TLCK. Compounds AQ-A1, AQ-D3, AQ-D4, AQ-E4 and AQ-E5 exhibited stronger acrosin inhibitory activities than control ISO-1. Especially, compound AQ-E5 displayed the most potent acrosin inhibitory activity in all the compounds, with an IC₅₀ of 0.01 μmol/mL. This study provided a new structural class for the development of novel acrosin inhibitory agents.     

Curcumin ameliorates TNF-α-induced ICAM-1 expression and subsequent THP-1 adhesiveness via the induction of heme oxygenase-1 in the HaCaT cells

Adhesion molecules such as ICAM-1 are important in the infiltration of leukocytes into the site of inflammation. In this study, we investigated the inhibitory effects of curcumin on ICAM-1 expression and monocyte adhesiveness as well as its underlying action mechanism in the TNF-α-stimulated keratinocytes. Curcumin induced expression of heme oxygenase-1 (HO-1) in the human keratinocyte cell line HaCaT. In addition, curcumin induced Nrf2 activation in dose- and time-dependent manners in the HaCaT cells. Curcumin suppressed TNF-α- induced ICAM-1 expression and subsequent monocyte adhesion, which were reversed by the addition of tin protoporphyrin IX (SnPP), a specific inhibitor of HO-1, or HO-1 knockdown using siRNA. Furthermore, Nrf2 knockdown using siRNA reversed the inhibitory effect of curcumin on the TNF-α-induced ICAM-1 expression and adhesion of monocytes to keratinocytes. These results suggest that curcumin may exert its anti-inflammatory activity by suppressing the TNF-α-induced ICAM-1 expression and subsequent monocyte adhesion via expression of HO-1 in the keratinocytes. [BMB Reports 2013;46(8): 410-415]     

Dedifferentiation-specific expression of MMP-9 and the effects of RA on its expression during salamander limb regeneration

The matrix metalloproteinases (MMPs) are well known to responsible for the degradation of extracellular matrix (ECM) during tissue remodelling such as wound healing, metamorphosis, and regeneration. In present study, gelatinase activities were investigated in normal and retinoic acid (RA)-treated limb regenerates. During the early phase of limb regeneration, gelatinase activities increased greatly, and RA caused the enhanced and prolonged gelatinase activities. We also isolated full length of Hynobius MMP-9, and its spatial and temporal expression profiles were examined in normal, RA-treated, and denervated limb regenerates. Whole mount in situ hybridization showed that the expression of MMP-9 increased in the wound epidermis at the wound healing stage and early phase of dedifferentiation stage. In addition, RA enhanced remarkably its expression both in terms of level and duration in the wound epidermis. However, expression signal of MMP-9 was barely detectable in denervated in limb regenerates. Our results may indicate that MMP-9 plays important role(s) in the dedifferentiation process by participating in ECM degradation and enhancement of MMP-9 expression and activity might be closely related to RA-evoked pattern duplication.     

Continuous rhamnolipid production using denitrifying Pseudomonas aeruginosa cells in hollow‐fiber bioreactor

Rhamnolipids are high‐value effective biosurfactants produced by Pseudomonas aeruginosa. Large‐scale production of rhamnolipids is still challenging especially under free‐cell aerobic conditions in which the highly foaming nature of the culture broth reduces the productivity of the process. Immobilized systems relying on oxygen as electron acceptor have been previously investigated but oxygen transfer limitation presents difficulties for continuous rhamnolipid production. A coupled system using immobilized cells and nitrate instead of oxygen as electron acceptor taking advantage of the ability of P. aeruginosa to perform nitrate respiration was evaluated. This denitrification‐based immobilized approach based on a hollow‐fiber setup eliminated the transfer limitation problems and was found suitable for continuous rhamnolipid production in a period longer than 1,500 h. It completely eliminated the foaming difficulties related to aerobic systems with a comparable specific productivity of 0.017 g/(g dry cells)‐h and allowed easy recovery of rhamnolipids from the cell‐free medium. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29: 346–351, 2013