Differential defense responses of tropical grasses to Mahanarva spectabilis (Hemiptera: Cercopidae) infestation.

The spittlebugs Mahanarva spectabilis economically challenges cattle production of neotropical regions, due to its voracious feeding on tropical grasses. Here, we evaluated biochemical responses of the interaction between M. spectabilis and the widely cultivated tropical grasses Brachiaria spp. (i.e., brizantha and decumbens) and elephant grasses (cvs. Roxo de Botucatu and Pioneiro), regarding lipoxygenases, protease inhibitors, phytohormones, and proteolytic activities in the midgut of M. spectabilis. The M. spectabilis-infested grasses increased lipoxygenases activity, except for cv. Pioneiro. The levels of the phytohormones jasmonic and abscisic acids were similarly low in all genotypes and increased under herbivory. Furthermore, salicylic acid concentration was constitutively higher in Brachiaria sp., increasing only in spittlebug-infested B. decumbens. M. spectabilis infestations did not induce increases of protease inhibitors in any forage grass type. The trypsin activity remained unaltered, and the total proteolytic activity increased only in B decumbens-fed insects. Our findings revealed that most forage grasses exposed to spittlebugs activate the lipoxygenases pathway, resulting in increased abscisic and jasmonic acids. However, greater amounts of these hormones do not induce protease inhibitory activity in response to spittlebug attack. This knowledge certainly helps to guide future projects aiming at reducing the impact of spittlebugs on forage production.

Detalhes bibliográficos

Principais autores:	BARROS, R. de A., VITAL, C. E., SILVA JÚNIOR, N. R., VARGAS, M. A. S., MONTEIRO, L. P., FAUSTINO, V. A., AUAD, A. M., PEREIRA, J. F., OLIVEIRA, E. E. de, RAMOS, H. J. O., OLIVEIRA, M. G. de A.
Outros Autores:	RAFAEL DE A. BARROS, Universidade Federal de Viçosa; CAMILO E. VITAL, Universidade Federal de Viçosa; NEILIER R. SILVA JÚNIOR, Universidade Federal de Viçosa; MANUEL A. S. VARGAS, Universidade Federal de Viçosa; LUANA P. MONTEIRO, Universidade Federal de Viçosa; VERONICA A. FAUSTINO, Universidade Federal de Viçosa; ALEXANDER MACHADO AUAD, CNPGL; JORGE FERNANDO PEREIRA, CNPGL; EUGENIO E. DE OLIVEIRA, Universidade Federal de Viçosa; HUMBERTO J. O. RAMOS, Universidade Federal de Viçosa; MARIA GORETI DE A. OLIVEIRA, Universidade Federal de Viçosa.
Formato:	Artigo de periódico biblioteca
Idioma:	Ingles English
Publicado em:	2021-09-12
Assuntos:	Hormônio, Inseto, Intestino, Protease, Cigarrinha das Pastagens, Pastagem, Hormones, Insects, Midgut,
Acesso em linha:	http://www.alice.cnptia.embrapa.br/alice/handle/doc/1134243 https://doi.org/10.1590/0001-3765202120191456
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