Project description:Stalk borers are major pests for some of the most important crops in the world, such as maize or rice. Plant defense mechanisms against these herbivores have been poorly investigated. The maize´s stalk responds to insect feeding activating defense genes including hormone biosynthetic-related or proteinase inhibitor transcripts. The most outstanding conclusion is that cells in the maize´s stalk undergo cell wall fortification after corn borer tunneling. We performed a gene expression profiling to identify those genes differentially expressed in maize after infestation with the corn borer S. nonagrioides.
Project description:Herbivorous insects having variable numbers of generations annually depending on climate and day length conditions are increasingly breeding additional generations driven by elevated temperature under the scenario of global warming, which will increase insect abundance and result in more frequent damage events. Theoretically, this relies on two premises, i.e., either an evolutionary shift to facultative diapause for an insect behaving an obligatory diapause or developmental plasticity to alter voltinism productively for an insect with facultative diapause before shortening photoperiods inducing diapause. Inter-population evidence supporting the premise (theory) comes primarily from a model system with voltinism linked to thermal gradients across latitude. We examined the intra-population evidence in the field (47°24' N, 123°68' E) with Ostrinia furnacalis, one of the most destructive pests, on corn in Asia and Pacific islands. The species was univoltine in high latitudinal areas (≤46° N). Divergence of the diapause feature (obligatory and facultative) was observed within the field populations from 2016 to 2021. Warmer climates would provoke more facultative diapause individuals to initiate a second generation, which will significantly drive the population to evolve toward facultative diapause (multi-voltinism). Both divergent diapause and temperature must be considered for accurate prediction of phenology and population dynamics in ACB.
Project description:Stalk borers are major pests for some of the most important crops in the world, such as maize or rice. Plant defense mechanisms against these herbivores have been poorly investigated. The maize´s stalk responds to insect feeding activating defense genes including hormone biosynthetic-related or proteinase inhibitor transcripts. The most outstanding conclusion is that cells in the maize´s stalk undergo cell wall fortification after corn borer tunneling. We performed a gene expression profiling to identify those genes differentially expressed in maize after infestation with the corn borer S. nonagrioides. Four genetically unrelated maize inbred lines (EP39, EP42, CM151 and PB130) were infested at VT (tasseling) developmental stage with a mass of approximately 40 eggs of S. nonagrioides laid on the sheath of the main ear. Another four biological replicates per genotype were used as control. Samples for RNA extraction were harvested fifteen days after infestation.
Project description:The most common ladybird beetle, Coccinella septempunctata L., is an excellent predator of crop pests such as aphids and white flies, and it shows a wide range of adaptability, a large appetite and a high reproductive ability. In this study, we collected female adults in three different states, i.e., non-diapause, diapause and diapause termination, for transcriptome sequencing. The experimental insects consisted of three different states as follows: Non-diapause female insects were reared at 24±1°C, with a RH of 70±10% and a 16:8 h light: dark (L: D) photoperiod and collected after their first oviposition. Female adults in diapause were reared at 18±1°C at an RH of 70±10% and a 10:14-h (L:D) photoperiod. The experimental diapause insects were collected after 30 days. Diapause-terminated adults were transferred to another climatic cabinet with the 30-day diapause insects and reared under the same conditions as the non-diapause insects. After their first oviposition, the female insects were collected and stored at -80°C. Three biological replicates per treatment (non-diapause, diapause, diapause-terminated) were sequenced using Illumina HiSeq 2500.
Project description:Purpose: transcriptome sequencing of Conopomorpha sinensis Methods: high-through Illumina HiSeqTM 2000 Results:66017 transcripts,35383 unigenes Conclusions:This study provided valuable transcriptome data for the litchi fruit borer, which was the first fundamental genomic basis for exploiting gene resources from the litchi fruit borer
Project description:Diapause is an environmentally programmed and hormonally regulated period of dormancy which makes an important part of the life-cycle in many species of invertebrates. In this study, using a RNAseq approach, we focused on very early stages of diapause induction in the larvae of drosophilid fly, Chymomyza costata by characterizing global patterns of gene expression associated with photoperiodic induction of diapause.
Project description:Diapause represents a crucial adaptive strategy used by insects to cope with changing environmental conditions. In North China, the Asian corn borer (Ostrinia furnacalis) enters a winter larval diapause stage. Although there is growing evidence implicating epigenetic mechanisms in diapause regulation, it remains unclear whether dynamic genome-wide profiles of epigenetic modifications exist during this process. By investigating multiple histone modifications, we have discovered the essential roles of H3K9me3 and H3K27me3 during diapause of the Asian corn borer. Building upon previous findings in vertebrates highlighting the connection between DNA methylation and repressive histone methylations, we have examined changes in the genome-wide profile of H3K9me3, H3K27me3, and DNA methylation at the nondiapause, prediapause, and diapause stages. Data analysis reveals significant alterations in these three modifications during diapause. Moreover, we observe a correlation between the H3K9me3 and H3K27me3 modification sites during diapause, whereas DNA modifications show little association with either H3K9me3 or H3K27me3. Integrative analysis of epigenome and expression data unveils the relationship between these epigenetic modifications and gene expression levels at corresponding diapause stages. Furthermore, by studying the function of histone modifications on genes known to be important in diapause, especially those involved in the juvenile pathway, we discover that the juvenile hormone pathway lies downstream from H3K9me3 and H3K27me3 histone modifications. Finally, the analysis of gene loci with modified modifications unreported in diapause uncovers novel pathways potentially crucial in diapause regulation. This study provides a valuable resource for future investigations aiming to elucidate the underlying mechanisms of diapause.