Maize plants sprayed with either jasmonic acid or its precursor, methyl linolenate, attract armyworm parasitoids, but the composition of attractants differs

Treatment of both uninfested and armyworm-infested maize plants with jasmonic acid (JA) is known to attract the parasitic wasp, Cotesia kariyai Watanabe (Hymenoptera: Braconidae). Here, we show that treatment with a methyl ester of a JA precursor, methyl linolenate (MeLin), also causes maize plants to attract this wasp, yet does not cause elevated levels of endogenous JA. The volatile chemicals emitted from either infested or uninfested maize plants treated with MeLin were qualitatively and quantitatively different from those emitted from JA-treated plants. Among compounds emitted from MeLin-treated plants, α-pinene and menthol attracted wasps in pure form in a two-choice test using a choice chamber. A mixture of methyl salicylate, α-copaene, and β-myrcene also attracted wasps. In contrast, (Z)-3-hexenyl acetate was among the main attractants for C. kariyai in JA-treated plants. These data show that in addition to JA, MeLin also has the potential to increase the host-finding ability of C. kariyai, but that the composition of attractants they induce differs

Herbivore-Specific, Density-Dependent Induction of Plant Volatiles: Honest or “Cry Wolf” Signals?

Plants release volatile chemicals upon attack by herbivorous arthropods. They do so commonly in a dose-dependent manner: the more herbivores, the more volatiles released. The volatiles attract predatory arthropods and the amount determines the probability of predator response. We show that seedlings of a cabbage variety (Brassica oleracea var. capitata, cv Shikidori) also show such a response to the density of cabbage white (Pieris rapae) larvae and attract more (naive) parasitoids (Cotesia glomerata) when there are more herbivores on the plant. However, when attacked by diamondback moth (Plutella xylostella) larvae, seedlings of the same variety (cv Shikidori) release volatiles, the total amount of which is high and constant and thus independent of caterpillar density, and naive parasitoids (Cotesia vestalis) of diamondback moth larvae fail to discriminate herbivore-rich from herbivore-poor plants. In contrast, seedlings of another cabbage variety of B. oleracea (var. acephala: kale) respond in a dose-dependent manner to the density of diamondback moth larvae and attract more parasitoids when there are more herbivores. Assuming these responses of the cabbage cultivars reflect behaviour of at least some genotypes of wild plants, we provide arguments why the behaviour of kale (B. oleracea var acephala) is best interpreted as an honest signaling strategy and that of cabbage cv Shikidori (B. oleracea var capitata) as a “cry wolf” signaling strategy, implying a conflict of interest between the plant and the enemies of its herbivores: the plant profits from being visited by the herbivore's enemies, but the latter would be better off by visiting other plants with more herbivores. If so, evolutionary theory on alarm signaling predicts consequences of major interest to students of plant protection, tritrophic systems and communication alike

Intermittent exposure to traces of green leaf volatiles triggers a plant response

Plants are known to mount a defensive response when exposed to volatile chemicals from other plants, but the critical concentration required for this response is not known. We showed that intermittent exposure over a period of 3 weeks to trace amounts (less than 140 pptV) of green leaf volatiles emitted by a freshly damaged Arabidopsis plant induced physiological (defensive) responses in undamaged neighbouring plants. These results demonstrated that plants can respond to long-term repeated exposures to subcritical amounts of chemical signals

Gefitinib induction followed by chemoradiotherapy in EGFR-mutant, locally advanced non-small-cell lung cancer: LOGIK0902/OLCSG0905 phase II study

Background: The role of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) induction coupled with standard concurrent chemoradiotherapy (CRT) is unclear in unresectable, stage III, EGFR-mutant non-small-cell lung cancer (NSCLC). Therefore, a phase II trial was conducted to evaluate the efficacy and safety of gefitinib induction followed by CRT in this disease setting. Patients and methods: Patients with unresectable, EGFR-mutant, stage III NSCLC were administered gefitinib monotherapy (250 mg/day) for 8 weeks. Subsequently, patients without disease progression during induction therapy were administered cisplatin and docetaxel (40 mg/m(2) each) on days 1, 8, 29, and 36 with concurrent radiotherapy at a total dose of 60 Gy. The primary endpoint was the 2-year overall survival (OS) rate, which was hypothesized to reach 85%, with a threshold of the lower limit of 60%. Results: Twenty patients (median age: 66 years; male/female: 9/11; histology: 20 adenocarcinoma; stage IIIA/IIIB: 9/11; and exon 19/21: 10/10) were enrolled. The 2-year OS rate was 90% (90% confidence interval: 71.4% to 96.8%), indicating that this trial met the primary objective. The overall response rate and 1- and 2-year progression-free survival rates were 85.0%, 58.1%, and 36.9%, respectively. Grade >= 3 adverse events (>10%) included hepatic toxicity during the induction phase and neutropenia and febrile neutropenia in the CRT phase. Radiation pneumonitis grade >= 3 or treatment-related death did not occur. Conclusions: This is the first prospective study to demonstrate the favorable efficacy and safety of EGFR-TKI induction followed by standard CRT in EGFR-mutant, stage III NSCLC. Further confirmatory studies are needed

Line Defects in Molybdenum Disulfide Layers

Layered molecular materials and especially MoS2 are already accepted as promising candidates for nanoelectronics. In contrast to the bulk material, the observed electron mobility in single-layer MoS2 is unexpectedly low. Here we reveal the occurrence of intrinsic defects in MoS2 layers, known as inversion domains, where the layer changes its direction through a line defect. The line defects are observed experimentally by atomic resolution TEM. The structures were modeled and the stability and electronic properties of the defects were calculated using quantum-mechanical calculations based on the Density-Functional Tight-Binding method. The results of these calculations indicate the occurrence of new states within the band gap of the semiconducting MoS2. The most stable non-stoichiometric defect structures are observed experimentally, one of which contains metallic Mo-Mo bonds and another one bridging S atoms

Differential Metabolisms of Green Leaf Volatiles in Injured and Intact Parts of a Wounded Leaf Meet Distinct Ecophysiological Requirements

Almost all terrestrial plants produce green leaf volatiles (GLVs), consisting of six-carbon (C6) aldehydes, alcohols and their esters, after mechanical wounding. C6 aldehydes deter enemies, but C6 alcohols and esters are rather inert. In this study, we address why the ability to produce various GLVs in wounded plant tissues has been conserved in the plant kingdom. The major product in completely disrupted Arabidopsis leaf tissues was (Z)-3-hexenal, while (Z)-3-hexenol and (Z)-3-hexenyl acetate were the main products formed in the intact parts of partially wounded leaves. 13C-labeled C6 aldehydes placed on the disrupted part of a wounded leaf diffused into neighboring intact tissues and were reduced to C6 alcohols. The reduction of the aldehydes to alcohols was catalyzed by an NADPH-dependent reductase. When NADPH was supplemented to disrupted tissues, C6 aldehydes were reduced to C6 alcohols, indicating that C6 aldehydes accumulated because of insufficient NADPH. When the leaves were exposed to higher doses of C6 aldehydes, however, a substantial fraction of C6 aldehydes persisted in the leaves and damaged them, indicating potential toxicity of C6 aldehydes to the leaf cells. Thus, the production of C6 aldehydes and their differential metabolisms in wounded leaves has dual benefits. In disrupted tissues, C6 aldehydes and their α,β-unsaturated aldehyde derivatives accumulate to deter invaders. In intact cells, the aldehydes are reduced to minimize self-toxicity and allow healthy cells to survive. The metabolism of GLVs is thus efficiently designed to meet ecophysiological requirements of the microenvironments within a wounded leaf

Hepatoblast and mesenchymal cell-specific gene-expression in fetal rat liver and in cultured fetal rat liver cells

The aim of this study was to determine whether passaged rat fetal liver cells are functional hepatoblasts. Hepatocyte/hepatoblast- and liver myofibroblast-gene-expressions were studied in adult and fetal rat liver tissues as well as in primary and passaged cultures of isolated rat fetal liver cells at both the mRNA and protein level. Desmin- and Alpha-Smooth Muscle Actin (SMA)-positive cells were located in the walls of liver vessels, whereas Desmin-positive/SMA-negative cells were distributed within the liver parenchyma. Primary cultures contained Prox1-positive hepatoblasts, Desmin/SMA-positive myofibroblasts and only a few Desmin-positive/SMA-negative cells. Albumin and alpha-fetoprotein (AFP) could be detected in the primary cultures and to a lesser extent after the first passage. The number of Desmin-positive/SMA-negative cells decreased with successive passage, such that after the second passage, only Desmin/SMA-positive cells could be detected. SMA-gene-expression increased during the passages, suggesting that myofibroblasts become the major cell population of fetal liver cell cultures over time. This observation needs to be taken into account, should passaged fetal liver cells be used for liver cell transplantation. Moreover it contradicts the concept of epithelial-mesenchymal transformation and suggests rather that selective overgrowth of mesenchymal cells occurs in culture

Serum Alpha-Fetoprotein Predicts Treatment Outcome in Chronic Hepatitis C Patients Regardless of HCV Genotype

We examined the association between serum alpha-fetoprotein (AFP) level and sustained virological response (SVR) in 93 chronic hepatitis C patients. The SVR rate was much higher among patients with serum AFP levels below rather than above the median value (5.7 ng/ml) (58.7% and 19.2%, respectively; P<0.0001). Serum AFP should be added to the list of factors predictive of treatment response in chronic hepatitis C