The Composite Effect of Transgenic Plant Volatiles for Acquired Immunity to Herbivory Caused by Inter-Plant Communications

A blend of volatile organic compounds (VOCs) emitted from plants induced by herbivory enables the priming of defensive responses in neighboring plants. These effects may provide insights useful for pest control achieved with transgenic-plant-emitted volatiles. We therefore investigated, under both laboratory and greenhouse conditions, the priming of defense responses in plants (lima bean and corn) by exposing them to transgenic-plant-volatiles (VOCos) including (E)-β-ocimene, emitted from transgenic tobacco plants (NtOS2) that were constitutively overexpressing (E)-β-ocimene synthase. When lima bean plants that had previously been placed downwind of NtOS2 in an open-flow tunnel were infested by spider mites, they were more defensive to spider mites and more attractive to predatory mites, in comparison to the infested plants that had been placed downwind of wild-type tobacco plants. This was similarly observed when the NtOS2-downwind maize plants were infested with Mythimna separata larvae, resulting in reduced larval growth and greater attraction of parasitic wasps (Cotesia kariyai). In a greenhouse experiment, we also found that lima bean plants (VOCos-receiver plants) placed near NtOS2 were more attractive when damaged by spider mites, in comparison to the infested plants that had been placed near the wild-type plants. More intriguingly, VOCs emitted from infested VOCos-receiver plants affected their conspecific neighboring plants to prime indirect defenses in response to herbivory. Altogether, these data suggest that transgenic-plant-emitted volatiles can enhance the ability to prime indirect defenses via both plant-plant and plant-plant-plant communications

454 Transcriptome pyrosequencing (P. persimilis_single)

454 Transcriptome pyrosequencing (P. persimilis_single

Data from: Temperature-dependent, behavioral, and transcriptional variability of a tritrophic interaction consisting of bean, herbivorous mite, and predator

Different organisms compensate for, and adapt to, environmental changes in different ways and therefore environmental changes affect animal–plant interactions. We consequently assessed the effect of temperature on a tritrophic system of the lima bean, the spider mite Tetranychus urticae, and the predatory mite Phytoseiulus persimilis. In this system the plant defends itself against T. urticae by emitting volatiles that attract P. persimilis. Over a range of 20 40°C the emission of volatiles by infested plants and the attraction of P. persimilis, peaked at 30°C but the number of eggs laid by T. urticae adults and the number of eggs consumed by P. persimilis, peaked at 35°C. This indicates that the spider mites and predatory mites performed best at a higher temperature than that at which most volatile attractants were produced. We used data from transcriptome pyrosequencing of the mites and found that P. persimilis up-regulated gene families for heat shock proteins (HSPs) and ubiquitin-associated proteins, whereas T. urticae did not. RNA interference-mediated gene suppression in P. persimilis, developed in the current study, revealed that predation on T. urticae eggs by P. persimilis fed with PpHsp70-1 dsRNA was reduced at 35°C, when the expression level of PpHsp70-1 was greatly increased but not at 25°C. Overall, our molecular and behavioral approaches revealed that the mode and tolerance of lima bean, T. urticae, and the predatory mite P. persimilis are distinctly affected by temperature variability, thereby making their tritrophic interactions temperature dependent

Acquired immunity of transgenic torenia plants overexpressing agmatine coumaroyltransferase to pathogens and herbivore pests

We investigated the ability of transgenic torenia (Scrophulariaceae) plants to resist fungi and arthropod herbivores. Torenia hybrida cv. Summerwave Blue was manipulated to produce Arabidopsis agmatine coumaroyltransferase (AtACT). This catalyses the last step in the biosynthesis of hydroxycinnamic acid amides (HCAAs) which function in defence. Transgenic plants accumulated substantial HCAAs, predominantly p-coumaroylagmatine, and the HCAAs were isomerized from the trans-form to the cis-form in planta. The transgenic line, accumulated the highest amount of endogenous HCAAs (CouAgm at 32.2 µM and total HCAAs at 47.5 µM) and this line was resistant to the necrotrophic fungus, Botrytis cinerea. There was no resistance, however, in their wild-type progenitors or in other transgenic lines accumulating low HCAA amounts. In contrast, the transformants were not significantly resistant to three representative herbivores, Frankliniella occidentalis, Aphis gossypii, and Tetranychus ludeni

Expression of Cancer Stem Cell Markers EpCAM and CD90 Is Correlated with Anti- and Pro-Oncogenic EphA2 Signaling in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer death worldwide. Additionally, the efficacy of targeted molecular therapies with multiple tyrosine kinase inhibitors is limited. In this study, we focused on the cellular signaling pathways common to diverse HCC cells and used quantitative reverse phase protein array (RPPA) and statistical analyses to elucidate the molecular mechanisms determining its malignancy. We examined the heterogeneity of 17 liver cancer cell lines by performing cluster analysis of their expression of CD90 and EpCAM cancer stem cell markers. Gaussian mixture model clustering identified three dominant clusters: CD90-positive and EpCAM-negative (CD90+), EpCAM-positive and CD90-negative (EpCAM+) and EpCAM-negative and CD90-negative (Neutral). A multivariate analysis by partial least squares revealed that the former two cell populations showed distinct patterns of protein expression and phosphorylation in the EGFR and EphA2 signaling pathways. The CD90+ cells exhibited higher abundance of AKT, EphA2 and its phosphorylated form at Ser897, whereas the EpCAM+ cells exhibited higher abundance of ERK, RSK and its phosphorylated form. This demonstrates that pro-oncogenic, ligand-independent EphA2 signaling plays a dominant role in CD90+ cells with higher motility and metastatic activity than EpCAM+ cells. We also showed that an AKT inhibitor reduced the proliferation and survival of CD90+ cells but did not affect those of EpCAM+ cells. Taken together, our results suggest that AKT activation may be a key pro-oncogenic regulator in HCC

Polyamines and jasmonic acid induce plasma membrane potential variations in lima bean

Exogenous polyamines [cadaverine (Cad), putrescine (Put), spermidine (Spd) and spermine (Spm)] elicit the production of volatiles in Lima bean (Phaseolus lunatus). Among the tested PAs, Spm induces the production of some volatile terpenoids that are known to be induced by the spider mite Tetranychus urticae. Spm treatment elicits the biosynthesis of Jasmonic acid (JA), a phytohormone known to regulate the production of the volatile terpenoids. The treatment with JA together with Spm resulted in the increased volatile emission, and predatory mites Phytoseiulus persimilis preferred JA and Spm-treated leaves over those treated with JA alone.5 JA and Spm treatment has no effects on polyamine oxidase (PAO) and Cu-amine oxidase (CuAO) but has a significant induction of calcium influx, ROS production, enzyme activities for NADPH-oxidase complex, superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase and glutathione peroxidase, and gene expressions except for NADPH-oxidase complex.5 Here, we report that a plasma membrane potential (Vm) depolarization was observed after polyamine perfusion with an increasing trend: Spm, Cad, Put and Spd. JA perfusion did not alter Vm but the perfusion of JA and the polyamines significantly increased Cad and Put Vm depolarization. When JA was perfused with polyamines, a negative correlation was found between Vm depolarization and the number of amino group of the polyamines tested

Volatile analysis

Volatile analysi