Ontogênese da folha e das galhas induzidas por Aceria lantanae Cook (Acarina:Eriophyidae) em Lantanacamara L. (Verbenaceae)

Abstract

-(Ontogenesis of the leaf and leaf galls induced by Aceria lantanae Cook (Acarina:Eriophyidae) in Lantana camara L. (Verbenaceae)). Aceria lantanae is a phytophagous mite commonly observed inducing galls in Lantana camara leaves. The comparative study of histological and histometric characteristics, during the ontogenesis of leaves and galls, aims to determine which of the healthy tissues morphogenetic events are altered by the galling herbivore. Leaf ontogenetical events of L. camara followed the pattern described in literature. Gall induction causes hyperplasia of epidermis and ground system. At growth and development stage, leaf lamina invagination gives rise to the nymphal chamber, where eriophids reproduce. The cell layer limiting this chamber constitutes the nutritive tissue, where inducers feed, and stimulate cell divisions. At the maturation stage, gall increase in size is followed by an increase in the number of A. lantanae individuals. Gall external covering is characterized by a high density of non-glandular trichomes whose morphotype is particular to the galls. The differentiation of emergencies and neoformation of vascular bundles promotes an increase in the flux of food resources to the inducers. Cell divisions in diverse angles alter the laminar pattern of the leaf firstly related to photosynthesis, and result in verrucous galls which guarantee an adequate microenvironment and nutrition source to A. lantanae colony. At senescent stage, nutritive tissue suberization occurs, indicating the end of the inducers feeding activity. The suberization of nutritive tissue indicates the end of cell cycles, an event that may be related to the death of the deutogyne female, or to the limits imposed by the age of L. camara host leaf.Key words -Aceria, development, Lantana, leaf anatomy, plant gall RESUMO -(Ontogênese da folha e das galhas induzidas por Aceria lantanae Cook (Acarina:Eriophyidae) em Lantana camara L. (Verbenaceae)). Aceria lantanae é um ácaro fitófago indutor de galhas em folhas de Lantana camara. O estudo comparativo de caracteres histológicos e histométricos durante a ontogênese foliar e das galhas visa determinar quais eventos da morfogênese dos tecidos sadios são alterados pelo galhador. A ontogênese foliar de L. camara segue os padrões descritos na literatura. A indução de galhas provoca hiperplasia da epiderme e do sistema fundamental. No estágio de crescimento e desenvolvimento, a invaginação da lâmina foliar origina a câmara ninfal, onde os eriofídeos se reproduzem. O revestimento interno dessa câmara constitui o tecido nutritivo, no qual os indutores se alimentam, estimulando as divisões celulares. No estágio de maturação, o aumento no tamanho da estrutura é acompanhado pelo aumento no número de indivíduos de A. lantanae. O revestimento externo da galha apresenta alta densidade de tricomas tectores, cujo morfotipo é particular às galhas. A diferenciação de emergências e a neoformação de feixes vasculares promove o aporte de nutrientes aos indutores. Divisões celulares em diversos...

Structural and histochemical profile of Lopesia sp. Rübsaamen 1908 pinnula galls on Mimosa tenuiflora (Willd.) Poir. in a Caatinga environment

“…The anatomical alterations from non-galled pinnulae toward galls -The structural alterations induced by Lopesia sp. on the pinnulae of M. tenuiflora are quite similar to those induced by other species of Cecidomyiidae in the neotropics (Arduin & Kraus 1995, Moura et al 2009, Oliveira & Isaias 2009. Cecidomyiidae galls commonly have parenchyma homogenization and the formation of sclerenchyma layers adjacent to the nutrient tissue (Rohfritsch 1992).…”

“…system, its primary function, i.e., protection against abiotic factors, may be performed by the thick periclinal cell walls, which can control the excess of water loss due to the high temperatures of Caatinga (Gal et al 2015). Together with the thick cell walls, the glandular and non-glandular trichomes observed both in host pinnula and galls may enhance the protection against unfavorable environmental features (Stone & Schonrogge 2003, Moura et al 2009. Also, gall tissues and trichomes are terpenoid-rich, which may add in chemical defense against natural enemies (Souza-Silva et al 2017).…”

“…An important aspect of the Cecidomyiidae is that they induce profound modifications in their host plant organs, both at the cell and tissue levels (Arduin & Kraus 1995, Moura et al 2009. After the establishment of the galling insect, the growth of gall tissues is associated with changes in the accumulation of carbohydrates, proteins, lipids, as well as secondary metabolites, such as phenols and alkaloids (Arya et al 1975, Amorim et al 2017.…”

The imbalance of redox homeostasis in arthropod-induced plant galls: Mechanisms of stress generation and dissipation

“…Insect-induced galls have complex tissues with typical features and functions [75,82], which deviate from the morphogenetic patterns of the host organs and are therefore elegant models for the study of developmental and physiological responses of plant cells to specific stimuli. These responses have been explored in temperate regions [5,14,84,88,89] and in the Neotropics [16,17,20,34,35,52,53,71,75]. Elicitor substances and hormones are believed to mediate plant-insect interactions [8,29,65,91,99], but the exact mechanisms of gall induction remain to be elucidated.…”

Phenotypic plasticity and similarity among gall morphotypes on a superhost, Baccharis reticularia (Asteraceae)

“…In fact, changes in the vascular parenchyma cells are possible due to their totipotency (Fosket 1994). The expression of this totipotency indicates competence to assume distinct developmental pathways reported in other galling herbivore-host plant systems (Souza et al 2000;Arduin et al 2005;Moura et al 2009;S a et al 2009), which, nevertheless, seems to be a functional constraint imposed by B. reticularia host cells.…”