• Main Authors: GRACIELA G. DIAS, BRUNO G. FERREIRA, GILSON R.P. MOREIRA, ROSY M.S. ISAIAS
• Format: Article
• Language: English
• Published: Academia Brasileira de Ciências 2013-03-01
• Series: Anais da Academia Brasileira de Ciências
• Subjects: galha de hemíptero; histometria; padrão de desenvolvimento; destinos celulares; hemipteran gall; histometry; developmental patterns; cell fates
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652013000100187

Galling sap-feeding insects are presumed to cause only minor changes in host plant tissues, because they usually do not require development of nutritive tissues for their own use. This premise was examined through comparison of the histometry, cytometry and anatomical development of non-galled leaves and galls of Calophya duvauae (Scott) (Hemiptera: Calophyidae) on Schinus polygamus (Cav.) Cabrera (Anacardiaceae). Cell fates changed from non-galled leaves to galls during the course of tissue differentiation. C. duvauae caused changes in dermal, ground, and vascular systems of the leaves of S. polygamus. Its feeding activity induced the homogenization of the parenchyma, and the neoformation of vascular bundles and trichomes. The histometric and cytometric data revealed compensatory effects of hyperplasia and cell hypertrophy in the epidermis, with hyperplasia predominating in the adaxial epidermis. There was a balance between these processes in the other tissues. Thus, we found major differences between the developmental pathways of non-galled leaves and galls. These changes were associated with phenotypic alterations related to shelter and appropriate microenvironmental conditions for the gall inducer. The nondifferentiation of a typical nutritive tissue in this case was compared to other non-phylogenetically related arthropod gall systems, and is suggested to result from convergence associated with the piercing feeding apparatus of the corresponding gall-inducer.<br>Sup&#245;e-se que insetos galhadores de h&#225;bito sugador causam menos altera&#231;&#245;es nos tecidos vegetais, j&#225; que eles usualmente n&#227;o necessitam de um tecido nutritivo diferenciado para sua alimenta&#231;&#227;o. Essa premissa foi examinada pelo uso da histometria, citometria e compara&#231;&#227;o do desenvolvimento de folhas n&#227;o galhadas e galhas de Calophya duvauae (Scott) (Hemiptera: Calophyidae) em Schinus polygamus (Cav.) Cabrera (Anacardiaceae). As galhas demonstraram altera&#231;&#245;es nos tipos celulares durante a diferencia&#231;&#227;o tecidual. C. duvauae causou mudan&#231;as nos sistemas de revestimento, fundamental e vascular das folhas de S. polygamus. A atividade alimentar induziu a homogeneiza&#231;&#227;o do par&#234;nquima, a neoforma&#231;&#227;o dos tecidos vasculares e tricomas. Os dados histom&#233;tricos revelaram efeitos compensat&#243;rios de hiperplasia e hipertrofia celular na epiderme, predominando a hiperplasia na epiderme adaxial. Houve um balan&#231;o entre esses processos nos demais tecidos. Assim, obtivemos diferen&#231;as expressivas entre as trajet&#243;rias de desenvolvimento das folhas com e sem galhas. Essas altera&#231;&#245;es foram associadas a altera&#231;&#245;es fenot&#237;picas relacionadas &#224; provis&#227;o de abrigo e microambiente adequado ao galhador. A n&#227;o diferencia&#231;&#227;o de um tecido nutritivo t&#237;pico neste caso foi comparada com sistemas de galhas induzidas por outros artr&#243;podes, sendo sugerido como uma converg&#234;ncia associada ao aparato alimentar perfurador do agente indutor.