title: Manipulation of host plant cells and tissues by gall-inducing insects and adaptive strategies used by different feeding guilds.
abstract: Biologists who study insect-induced plant galls are faced with the overwhelming diversity of plant forms and insect species. A challenge is to find common themes amidst this diversity. We discuss common themes that have emerged from our cytological and histochemical studies of diverse neotropical insect-induced galls. Gall initiation begins with recognition of reactive plant tissues by gall inducers, with subsequent feeding and/or oviposition triggering a cascade of events. Besides, to induce the gall structure insects have to synchronize their life cycle with plant host phenology. We predict that reactive oxygen species (ROS) play a role in gall induction, development and histochemical gradient formation. Controlled levels of ROS mediate the accumulation of (poly)phenols, and phytohormones (such as auxin) at gall sites, which contributes to the new cell developmental pathways and biochemical alterations that lead to gall formation. The classical idea of an insect-induced gall is a chamber lined with a nutritive tissue that is occupied by an insect that directly harvests nutrients from nutritive cells via its mouthparts, which function mechanically and/or as a delivery system for salivary secretions. By studying diverse gall-inducing insects we have discovered that insects with needle-like sucking mouthparts may also induce a nutritive tissue, whose nutrients are indirectly harvested as the gall-inducing insects feeds on adjacent vascular tissues. Activity of carbohydrate-related enzymes across diverse galls corroborates this hypothesis. Our research points to the importance of cytological and histochemical studies for elucidating mechanisms of induced susceptibility and induced resistance.
authors.affiliation: Universidade Federal de Uberlândia (UFU), Instituto de Biologia (INBIO), Campus Umuarama, Caixa Postal 593, Av. Pará 1720, CEP 38400-902 Uberlândia, MG, Brazil. Electronic address: denisoliveira@inbio.ufu.br.
authors.forename: D C
authors.initials: DC
authors.lastname: Oliveira
authors.affiliation: Universidade Federal de Minas Gerais (UFMG), Instituto de Ciências Biológicas, Departamento de Botânica, Av. Antônio Carlos 6627, Caixa Postal 486, Pampulha, CEP 31270-901 Belo Horizonte, MG, Brazil. Electronic address: rosy@icb.ufmg.br.
authors.forename: R M S
authors.initials: RMS
authors.lastname: Isaias
authors.affiliation: Ecologia Evolutiva & Biodiversidade/DBG, ICB/Universidade Federal de Minas Gerais, CP 486, 31270-901 Belo Horizonte, MG, Brazil; Department of Biology, Stanford University, Stanford, CA 94305, USA. Electronic address: gw.fernandes@gmail.com.
authors.forename: G W
authors.initials: GW
authors.lastname: Fernandes
authors.affiliation: Universidade Federal de Minas Gerais (UFMG), Instituto de Ciências Biológicas, Departamento de Botânica, Av. Antônio Carlos 6627, Caixa Postal 486, Pampulha, CEP 31270-901 Belo Horizonte, MG, Brazil. Electronic address: bruno.garcia.ferreira@gmail.com.
authors.forename: B G
authors.initials: BG
authors.lastname: Ferreira
authors.affiliation: Universidade Federal de Minas Gerais (UFMG), Instituto de Ciências Biológicas, Departamento de Botânica, Av. Antônio Carlos 6627, Caixa Postal 486, Pampulha, CEP 31270-901 Belo Horizonte, MG, Brazil; Universidade Federal de Goiás, Instituto de Ciências Biológicas 1, Departamento de Botânica, Sala 203. Avenida Esperança, s/n, Câmpus Samambaia. CEP 74.690-900 Goiânia, GO, Brazil. Electronic address: rgscarneiro@gmail.com.
authors.forename: R G S
authors.initials: RGS
authors.lastname: Carneiro
authors.affiliation: Universidade Federal de Uberlândia (UFU), Instituto de Biologia (INBIO), Campus Umuarama, Caixa Postal 593, Av. Pará 1720, CEP 38400-902 Uberlândia, MG, Brazil. Electronic address: fuzaro.leandro@gmail.com.
authors.forename: L
authors.initials: L
authors.lastname: Fuzaro
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D006790:Host-Parasite Interactions; D007313:Insecta / Q000502:physiology*; D059828:Plant Cells / Q000469:parasitology*; D010937:Plant Growth Regulators / Q000502:physiology; D010941:Plant Tumors / Q000469:parasitology*; D010944:Plants / Q000469:parasitology*
chemical_list: D010937:Plant Growth Regulators
keywords: Biotic stress; Gall induction; Insect nutrition; Nutritive tissue; Plant galls