Project description:The extreme generalist two-spotted spider mite, Tetranychus urticae, which is documented to feed on more than 1100 plant hosts, is becoming an increasingly important agricultural pest. Historically, as studies of plant-herbivore interactions have focused largely on insects, considerably less research has investigated plant responses to spider mite herbivores, especially in grasses. To identify intraspecific differences in maize response to T. urticae, we collected RNA-seq data from three maize (Zea mays) inbred lines (B73, B75 and B49) as well as two F1 lines arising from crosses between B73 x B75 and B73 x B96. For each maize line, RNA-seq data was collected from uninfested leaves (control) and leaves infested with T. urticae for 24 hours.
Project description:Plants perceive herbivory induced volatiles and respond to them by upregulating their defenses. So far, the organs responsible for volatile perception remain poorly described. Here, we show that responsiveness to the herbivory induced green leaf volatile (Z)-3-hexenyl acetate (HAC) in terms of volatile emission, transcriptional regulation and jasmonate defense hormone activation is largely constrained to younger maize leaves. Older leaves are much less sensitive to HAC. In a given leaf, responsiveness to HAC is high at immature developmental stages and drops off rapidly during maturation. Responsiveness to the non-volatile elicitor ZmPep3 shows an opposite pattern, demonstrating that this form of hyposmia (i.e. decreased sense of smell) is not due to a general defect in jasmonate defense signaling in mature leaves. Neither stomatal conductance nor leaf cuticle composition explain the unresponsiveness of older leaves to HAC, suggesting perception mechanisms upstream of jasmonate signaling as driving factors. Finally, we show that hyposmia in older leaves is not restricted to HAC, and extends to the full blend of herbivory induced volatiles. In conclusion, our work identifies immature maize leaves as dominant stress volatile sensing organs. The tight spatiotemporal control of volatile perception may facilitate within-plant defense signaling to protect young leaves, and may allow plants with complex architectures to explore the dynamic odor landscapes at the outer periphery of their shoots
Project description:Spider mites, including the two-spotted spider mite (Tetranychus urticae, TSSM) and the Banks grass mite (Oligonychus pratensis, BGM), are becoming increasingly important agricultural pests. The TSSM is an extreme generalist documented to feed on more than 1100 plant hosts. In contrast, the BGM is a grass specialist, with hosts including important cereal crops like maize, wheat, and sorghum. Historically, studies of plant-herbivore interactions have focused largely on insects. As such, far less is known about plant responses to spider mite herbivores, especially in grasses, and whether responses differ between generalist and specialist mites. To identify plant defense pathways responding to spider mites, we collected time course RNA-seq data from maize (Zea mays) infested with TSSMs and BGMs. Additionally, and as a comparison to the physical damage caused by spider mite feeding, a wounding treatment was also included. In total, four biological samples were generated per treatment.
Project description:The objective of this study was to decipher the molecular basis of feed efficiency in meat-type chicken using duodenum tissues from a chicken population divergently selected for residual feed intake (RFI). Residual feed intake is the deviation of expected feed intake from actual feed intake. Chickens that consume less feed than expected are efficient (LRFI) and chickens that consume more feed than expected are inefficient (HRFI). A divergent selection for RFI was undertaken using an unselected random bred chicken population. RFI at day 35-42 was used as a criterion for selecting low (LRFI) and high (HRFI) RFI. Duodenum tissues were collected from 16 male chickens under sterile conditions experimentation. Tissues were collected from 4 males at days 35 and 42 in each line.
Project description:• Herbivore-induced plant volatiles (HIPVs), in addition to attracting natural enemies of herbivores, can serve a signaling function within plants by acting as wound signals that induce or prime defenses. However, particularly in woody plants, which compounds within HIPV blends are capable of acting as signaling molecules are largely unknown. • Leaves of hybrid poplar (Populus deltoides x nigra) saplings were exposed in vivo to naturally wound-emitted concentrations of the green leaf volatile (GLV) cis-3-hexenyl acetate (z3HAC) and then subsequently fed upon by gypsy moth larvae (Lymantria dispar L.). Volatiles were collected throughout the experiments, and leaf tissue was collected to measure phytohormone levels and expression of defense-related genes. • Relative to controls, z3HAC-exposed leaves had higher levels of jasmonic acid and linolenic acid following gypsy moth feeding. Further, z3HAC primed transcripts of phytohormone signaling (lipoxygenase 1) and direct defense (a Kunitz proteinase inhibitor) genes. These qRT-PCR results were supported by microarray analysis using the AspenDB 7K EST microarray containing ~5400 unique gene models. Moreover, z3HAC also primed the release of herbivore-induced terpene volatiles. • The widespread priming response suggests an adaptive benefit to detecting z3HAC as a wound signal. Thus, woody plants can detect and use z3HAC as a signaling cue to prime defenses before actually experiencing damage. GLVs may therefore have important ecological functions in arboreal ecosystems.
Project description:Plant volatiles can mediate plant-plant communication in the sense that plants attacked by herbivores can signal their unattacked neighbors of danger by emitting HIPVs. We call this the priming effect. Since the plant defense response is a systematic process involving numerous pathways and genes,to characterize the priming process, a time course study using a genome-wide microarray may provide more accurate information about the priming process. Furthermore, to what extent do the priming process and direct defense share similar gene expression profiles or pathways are also not clear. We used microarray to detect the priming effect of plant volatiles to healthy Arabidopsis thaliana, and the effect of direct leafminer feeding to Arabidopsis thalianas. A system using Lima bean plants, from which HIPVs can be effectively induced by leafminer feeding, as emitters and Arabidopsis thaliana as receivers is used to track the priming process between neighbor plants. The Arabisopsis thaliana seedlings were treated by volatiles from leafminer fed lima bean for 24h or 48h for RNA extraction and hybridization on Affymetrix microarrays. The Arabisopsis thaliana seedlings fed by leafminer directly were also collected The for RNA extraction and hybridization on Affymetrix micorarrays. We want to explore the response of Arabidopsis thaliana to priming volatiles during a 24h-48h time course. We also want to compare the effect of priming and direct leafminer feeding.
Project description:Maize LOB30 (Zm00001d036435) is a transcription factor and is specifically expressed in anthers. Our previous RNA-seq data showed that expression of some genes were upregualted in maize lob30 mutant maize anthers. To confirm these genes are the downstrem target genes, we generated proLOB30: GFP-LOB30 transgenic maize lines, collected stage 9 to stage10 anther materials and performed ChIP-seq using the GFP antibody.
Project description:For the toxicological risk assessment of genetically modified (GM) food components, the European Food Safety Agency advises to use an adapted version of the 90-day oral toxicity study in rodents, originally designed for the toxicity testing of chemicals. Since in GM crop testing scenarios the crop under evaluation is specifically intended as a food / feed component, some testing aspects are conceptually different from testing chemical compounds and thus need careful consideration. One key consideration relates to the appropriate dose level to evaluate the GM crop as a component of the experimental diet. The aim of this study was to develop and optimize methods that are required for advancing the use of zebrafish feeding trials for the toxicological safety evaluation of GM crops. Using maize as a case study, we investigated the effects of an increasing maize substitution dose level in the diets of zebrafish, using non-GM maize. In addition, we investigated the effect of the presence of maize in the diets (0% or 25% of maize substitution levels) on mRNA transcriptional profiles in the zebrafish liver.
Project description:Genotype and nitrogen-dosage effect on maize leaves collected at V8 leaf stage B73 is a model maize genotype while Illinois high protein line (IHP) is a metabolic extreme selected for higher grain protein concentration. It is a well known fact that the leaves serve as source and earshoot as a sink. Microarray analysis of V8 leaf collected from B73 and IHP genotypes grown at vairable nitrogen applications. Keywords: Genotype and N-treatment response
Project description:Spider mites, including the two-spotted spider mite (Tetranychus urticae, TSSM) and the Banks grass mite (Oligonychus pratensis, BGM), are becoming increasingly important agricultural pests. The TSSM is an extreme generalist documented to feed on more than 1100 plant hosts. In contrast, the BGM is a grass specialist, with hosts including important cereal crops like maize, wheat, sorghum and barley. Historically, studies of plant-herbivore interactions have focused largely on insects. However, far less is known about plant responses to spider mite herbivores, especially in grasses, and whether responses differ between generalists and specialists. To identify plant defense pathways responding to spider mites, we collected time course RNA-seq data from barley (Hordeum vulgare L.) infested with TSSMs and BGMs. Additionally, and as a comparison to the physical damage caused by spider mite feeding, a wounding treatment was also included.