Revealing insect herbivory-induced phenolamide metabolism: from single genes to metabolic network plasticity analysis.

The phenylpropanoid metabolic space comprises a network of interconnected metabolic branches that contribute to the biosynthesis of a large array of compounds with functions in plant development and stress adaptation. During biotic challenges, such as insect attack, a major rewiring of gene networks associated with phenylpropanoid metabolism is observed. This rapid reconfiguration of gene expression allows prioritized production of metabolites that help the plant solve ecological problems.

The roots of plant defenses: integrative multivariate analyses uncover dynamic behaviors of gene and metabolic networks of roots elicited by leaf herbivory.

High-throughput analyses have frequently been used to characterize herbivory-induced reconfigurations in plant primary and secondary metabolism in above- and below-ground tissues, but the conclusions drawn from these analyses are often limited by the univariate methods used to analyze the data. Here we use our previously described multivariate time-series data analysis to evaluate leaf herbivory-elicited transcriptional and metabolic dynamics in the roots of Nicotiana attenuata. We observed large, but transient, systemic responses in the roots that contrasted with the pattern of co-linearity observed in the up- and downregulation of genes and metabolites across the entire time series in treated and systemic leaves.

The CCHamide 1 receptor modulates sensory perception and olfactory behavior in starved Drosophila.

The olfactory response of the vinegar fly Drosophila melanogaster to food odor is modulated by starvation. Here we show that this modulation is not restricted to food odors and their detecting sensory neurons but rather increases the behavioral response to odors as different as food odors, repellents and pheromones. The increased behavioral responsiveness is paralleled by an increased physiological sensitivity of sensory neurons regardless whether they express olfactory or ionotropic receptors and regardless whether they are housed in basiconic, coeloconic, or trichoid sensilla.

An integrative statistical method to explore herbivory-specific responses in plants.

Spatial-temporal coordination between multiple processes/pathways is a key determinant of whole-organism transcriptome and metabolome reconfigurations in plants' response to biotic stresses. To explore tissue-based interdependencies in Nicotiana attenuata's resistance to insect attack, we performed time course analyses of the plant's transcriptome and metabolome in herbivory-elicited source leaves and unelicited sink leaves and roots. To dissect the multidimensionality of these responses, we have recently designed a novel approach of constructing interactive motifs by combining an extended self-organizing maps (SOM) based dimensionality reduction method with bootstrap-based non-parametric AN OVA models.

Deciphering herbivory-induced gene-to-metabolite dynamics in Nicotiana attenuata tissues using a multifactorial approach.

In response to biotic stresses, such as herbivore attack, plants reorganize their transcriptomes and reconfigure their physiologies not only in attacked tissues but throughout the plant. These whole-organismic reconfigurations are coordinated by a poorly understood network of signal transduction cascades. To explore tissue-based interdependencies in the resistance of Nicotiana attenuata to insect attack, we conducted time-series transcriptome and metabolome profiling of herbivory-elicited source leaves and unelicited sink leaves and roots.

Tissue specific diurnal rhythms of metabolites and their regulation during herbivore attack in a native tobacco, Nicotiana attenuata.

Ecological performance is all about timing and the endogenous clock that allows the entrainment of rhythms and anticipation of fitness-determining events is being rapidly characterized. How plants anticipate daily abiotic stresses, such as cold in early mornings and drought at noon, as well as biotic stresses, such as the timing of pathogen infections, is being explored, but little is known about the clock's role in regulating responses to insect herbivores and mutualists, whose behaviors are known to be strongly diurnally regulated and whose attack is known to reconfigure plant metabolomes. We developed a liquid chromatography-mass spectrometry procedure and analyzed its output with model-based peak picking algorithms to identify metabolites with diurnal accumulation patterns in sink/source leaves and roots in an unbiased manner.