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Ian T Baldwin - One of the best experts on this subject based on the ideXlab platform.

  • transcriptome profiling reveals differential gene expression of detoxification enzymes in a hemimetabolous tobacco pest after feeding on jasmonate silenced nicotiana attenuata Plants
    BMC Genomics, 2016
    Co-Authors: Cristina M Crava, Christoph Brutting, Ian T Baldwin
    Abstract:

    The evolutionary arms race between Plants and Insects has driven the co-evolution of sophisticated defense mechanisms used by Plants to deter herbivores and equally sophisticated strategies that enable phytophagous Insects to rapidly detoxify the Plant’s defense metabolites. In this study, we identify the genetic determinants that enable the mirid, Tupiocoris notatus, to feed on its well-defended host Plant, Nicotiana attenuata, an outstanding model for Plant-Insect Interaction studies. We used an RNAseq approach to evaluate the global gene expression of T. notatus after feeding on a transgenic N. attenuata line which does not accumulate jasmonic acid (JA) after herbivory, and consequently accumulates very low levels of defense metabolites. Using Illumina sequencing, we generated a de novo assembled transcriptome which resulted in 63,062 contigs (putative transcript isoforms) contained in 42,610 isotigs (putative identified genes). Differential expression analysis based on RSEM-estimated transcript abundances identified 82 differentially expressed (DE) transcripts between T. notatus fed on wild-type and the defenseless Plants. The same analysis conducted with Corset-estimated transcript abundances identified 59 DE clusters containing 85 transcripts. In both analyses, a larger number of DE transcripts were found down-regulated in mirids feeding on JA-silenced Plants (around 70%). Among these down-regulated transcripts we identified seven transcripts possibly involved in the detoxification of N. attenuata defense metabolite, specifically, one glutathione-S-transferase (GST), one UDP-glucosyltransferase (UGT), five cytochrome P450 (P450s), and six serine proteases. Real-time quantitative PCR confirmed the down-regulation for six transcripts (encoding GST, UGT and four P450s) and revealed that their expression was only slightly decreased in mirids feeding on another N. attenuata transgenic line specifically silenced in the accumulation of diterpene glycosides, one of the many classes of JA-mediated defenses in N. attenuata. The results provide a transcriptional overview of the changes in a specialist hemimetabolous Insect associated with feeding on host Plants depleted in chemical defenses. Overall, the analysis reveals that T. notatus responses to host Plant defenses are narrow and engages P450 detoxification pathways. It further identifies candidate genes which can be tested in future experiments to understand their role in shaping the T. notatus-N. attenuata Interaction.

  • the layers of Plant responses to Insect herbivores
    Annual Review of Entomology, 2016
    Co-Authors: Meredith C Schuman, Ian T Baldwin
    Abstract:

    Plants collectively produce hundreds of thousands of specialized metabolites that are not required for growth or development. Each species has a qualitatively unique profile, with variation among individuals, growth stages, and tissues. By the 1950s, entomologists began to recognize the supreme importance of these metabolites in shaping Insect herbivore communities. Plant defense theories arose to address observed patterns of variation, but provided few testable hypotheses because they did not distinguish clearly among proximate and ultimate causes. Molecular Plant-Insect Interaction research has since revealed the sophistication of Plant metabolic, developmental, and signaling networks. This understanding at the molecular level, rather than theoretical predictions, has driven the development of new hypotheses and tools and pushed the field forward. We reflect on the utility of the functional perspective provided by the optimal defense theory, and propose a conceptual model of Plant defense as a series of layers each at a different level of analysis, illustrated by advances in the molecular ecology of Plant-Insect Interactions.

  • independently silencing two photosynthetic proteins in nicotiana attenuata has different effects on herbivore resistance
    Plant Physiology, 2008
    Co-Authors: Sirsha Mitra, Ian T Baldwin
    Abstract:

    Insect attack frequently down-regulates photosynthetic proteins. To understand how this influences the Plant-Insect Interaction, we transformed Nicotiana attenuata to independently silence ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCase) activase (RCA) and RuBPCase and selected lines whose photosynthetic capacity was similarly reduced. Decreases in Plant growth mirrored the decreases in photosynthesis, but the effects on herbivore performance differed. Both generalist (Spodoptera littoralis) and specialist (Manduca sexta) larvae grew larger on RCA-silenced Plants, which was consistent with decreased levels of trypsin protease inhibitors and diterpene glycosides and increased levels of RuBPCase, the larvae's main dietary protein. RCA-silenced Plants were impaired in their attack-elicited jasmonate (JA)-isoleucine (Ile)/leucine levels, but RuBPCase-silenced Plants were not, a deficiency that could not be restored by supplementation with Ile or attributed to lower transcript levels of JAR4/6, the key enzyme for JA-Ile conjugation. From these results, we infer that JA-Ile/leucine signaling and the herbivore resistance traits elicited by JA-Ile are influenced by adenylate charge, or more generally, carbon availability in RCA- but not RuBPCase-silenced Plants. Growth of generalist larvae on RuBPCase-silenced Plants did not differ from growth on empty vector controls, but the specialist larvae grew faster on RuBPCase-silenced Plants, which suggests that the specialist can better tolerate the protein deficiency resulting from RuBPCase silencing than the generalist can. We conclude that the Plant-herbivore Interaction is more influenced by the particular mechanisms that reduce photosynthetic capacity after herbivore attack than by the magnitude of the decrease, which highlights the value of understanding defense mechanisms in evaluating growth-defense tradeoffs.

Claudio C Ramirez - One of the best experts on this subject based on the ideXlab platform.

Michael S Engel - One of the best experts on this subject based on the ideXlab platform.

  • a defensive behavior and Plant Insect Interaction in early cretaceous amber the case of the immature lacewing hallucinochrysa diogenesi
    Arthropod Structure & Development, 2016
    Co-Authors: Ricardo Perezde La Fuente, Xavier Delclos, Enrique Penalver, Michael S Engel
    Abstract:

    Amber holds special paleobiological significance due to its ability to preserve direct evidence of biotic Interactions and animal behaviors for millions of years. Here we review the finding of Hallucinochrysa diogenesi Perez-de la Fuente, Delclos, Penalver and Engel, 2012, a morphologically atypical larva related to modern green lacewings (Insecta: Neuroptera) that was described in Early Cretaceous amber from the El Soplao outcrop (northern Spain). The fossil larva is preserved with a dense cloud of fern trichomes that corresponds to the trash packet the Insect gathered and carried on its back for camouflaging and shielding, similar to that which is done by its extant relatives. This finding supports the prominent role of wildfires in the paleoecosystem and provides direct evidence of both an ancient Plant–Insect Interaction and an early acquisition of a defensive behavior in an Insect lineage. Overall, the fossil of H. diogenesi showcases the potential that the amber record offers to reconstruct not only the morphology of fossil arthropods but, more remarkably, their lifestyles and ecological relationships.

  • early evolution and ecology of camouflage in Insects
    Proceedings of the National Academy of Sciences of the United States of America, 2012
    Co-Authors: Ricardo Perezde La Fuente, Xavier Delclos, Enrique Penalver, Mariela Speranza, Jacek Wierzchos, Carmen Ascaso, Michael S Engel
    Abstract:

    Taxa within diverse lineages select and transport exogenous materials for the purposes of camouflage. This adaptive behavior also occurs in Insects, most famously in green lacewing larvae who nestle the trash among setigerous cuticular processes, known as trash-carrying, rendering them nearly undetectable to predators and prey, as well as forming a defensive shield. We report an exceptional discovery of a green lacewing larva in Early Cretaceous amber from Spain with specialized cuticular processes forming a dorsal basket that carry a dense trash packet. The trash packet is composed of trichomes of gleicheniacean ferns, which highlight the presence of wildfires in this early forest ecosystem. This discovery provides direct evidence of an early acquisition of a sophisticated behavioral suite in stasis for over 110 million years and an ancient Plant–Insect Interaction.

Christian C Figueroa - One of the best experts on this subject based on the ideXlab platform.

Ricardo Perezde La Fuente - One of the best experts on this subject based on the ideXlab platform.

  • a defensive behavior and Plant Insect Interaction in early cretaceous amber the case of the immature lacewing hallucinochrysa diogenesi
    Arthropod Structure & Development, 2016
    Co-Authors: Ricardo Perezde La Fuente, Xavier Delclos, Enrique Penalver, Michael S Engel
    Abstract:

    Amber holds special paleobiological significance due to its ability to preserve direct evidence of biotic Interactions and animal behaviors for millions of years. Here we review the finding of Hallucinochrysa diogenesi Perez-de la Fuente, Delclos, Penalver and Engel, 2012, a morphologically atypical larva related to modern green lacewings (Insecta: Neuroptera) that was described in Early Cretaceous amber from the El Soplao outcrop (northern Spain). The fossil larva is preserved with a dense cloud of fern trichomes that corresponds to the trash packet the Insect gathered and carried on its back for camouflaging and shielding, similar to that which is done by its extant relatives. This finding supports the prominent role of wildfires in the paleoecosystem and provides direct evidence of both an ancient Plant–Insect Interaction and an early acquisition of a defensive behavior in an Insect lineage. Overall, the fossil of H. diogenesi showcases the potential that the amber record offers to reconstruct not only the morphology of fossil arthropods but, more remarkably, their lifestyles and ecological relationships.

  • early evolution and ecology of camouflage in Insects
    Proceedings of the National Academy of Sciences of the United States of America, 2012
    Co-Authors: Ricardo Perezde La Fuente, Xavier Delclos, Enrique Penalver, Mariela Speranza, Jacek Wierzchos, Carmen Ascaso, Michael S Engel
    Abstract:

    Taxa within diverse lineages select and transport exogenous materials for the purposes of camouflage. This adaptive behavior also occurs in Insects, most famously in green lacewing larvae who nestle the trash among setigerous cuticular processes, known as trash-carrying, rendering them nearly undetectable to predators and prey, as well as forming a defensive shield. We report an exceptional discovery of a green lacewing larva in Early Cretaceous amber from Spain with specialized cuticular processes forming a dorsal basket that carry a dense trash packet. The trash packet is composed of trichomes of gleicheniacean ferns, which highlight the presence of wildfires in this early forest ecosystem. This discovery provides direct evidence of an early acquisition of a sophisticated behavioral suite in stasis for over 110 million years and an ancient Plant–Insect Interaction.