RESUMO
Tobacco hornworm (Manduca sexta, THW) is a voracious pest of tomato and potato. StZFP2 is a Q-type C2H2 zinc finger transcription factor (TF) that is induced upon wounding and infestation. Previous work has shown that Q-type C2H2 TFs are involved in stress responses and when over expressed, can enhance protection against drought, salinity or pathogen infection. Twelve transgenic lines (S1-S12) were tested that over-express StZFP2. Feeding S6 or S8 to THW significantly lowered larval weight (21-37%) as well as increased expression of StPIN2 in comparison to untransformed Kennebec. The increase in StPIN2, a classic marker for insect defense in potato, is consistent with the decreases in larval weight gain.
Assuntos
Manduca/patogenicidade , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Solanum lycopersicum/metabolismo , Solanum lycopersicum/parasitologia , Solanum tuberosum/metabolismo , Solanum tuberosum/parasitologia , Animais , Larva/patogenicidade , Solanum lycopersicum/genética , Folhas de Planta/genética , Folhas de Planta/metabolismo , Folhas de Planta/parasitologia , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/parasitologia , Solanum tuberosum/genéticaRESUMO
During tomato fruit ripening, photosynthetically competent thylakoid membranes are broken down and replaced by membranous deposits of carotenoids. Few of the proteins involved in this transition have been identified. We have used chloroplast protein import assays as a means to identify two cDNAs that encode proteins destined for the developing chromoplast. One of the cDNAs had unexpected properties and its biological function has not been determined. However, the other cDNA encodes a plastid-localized low-MW heat shock protein (hsp). The steady-state level of RNA corresponding to this cDNA increased several-fold during tomato ripening, and the amount of RNA induced by heat stress increased dramatically during this process. These observations suggest a new role for this stress protein in protecting the plastid during the dismantling of the thylakoid membranes or during the buildup of carotenoids.