Orientador: Jorge Vega / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-08T03:46:44Z (GMT). No. of bitstreams: 1 Gouvea_JorgeAlbertode_D.pdf: 1143224 bytes, checksum: 108744e4f1f8e8833644140838007856 (MD5) Previous issue date: 2006 / Resumo:A aplicação de determinados reguladores de crescimento em plantas pode resultar na indução de resistência contra ataques subseqüentes de patógenos. Este fenômeno é conhecido como resistência sistêmica adquirida (SAR) e vários mecanismos estão envolvidos, entre eles a resposta de hipersensibilidade (HR), o aumento na atividade das enzimas peroxidases (POX) e da fenilalanina amônia-liase (PAL) nos tecidos resistentes. A fim de se detenninar o efeito do ácido salicílico (AS) e de um brassinolídeo (BR 16) na resposta hipersensível, plantas de feijoeiro (Phaseolus vulgaris L.), cultivar Moruna (nc) foram tratadas com estes reguladores de crescimento e inoculadas com o Southern bean mosaic virus (SBMV). Detenninou-se o número de lesões necróticas das folhas primárias e a atividade das enzimas guaiacol peroxidases (g-POX) e PAL. Houve uma redução significativa no número de lesões necróticas nas plantas tratadas com ambos os reguladores de crescimento e um aumento significativo na atividade das g-POX, mas nenhum efeito na atividade da PAL. O efeito da aplicação de AS e BR 16 na resposta suscetível foi verificado através da aplicação destes reguladores de crescimento em plantas de feijoeiro da cultivar lalo, inoculadas com o SBMV. Os tratamentos promoveram uma redução significativa na concentração viral na sa folha trifoliolada, 28 dias após a inoculação das folhas primárias. Os resultados indicam que as aplicações de ácido salicílico e do brassinolídeo BR 16 podem ter promovido uma indução de resistência tanto local quanto sistêmica, em plantas de feijoeiro. O aumento na atividade das enzimas g-POX, envolvidas nos processos de detoxificação de espécies reativas de oxigênio, promovido pelo tratamento com ambos os reguladores de crescimento, sugere uma participação destas na redução do número de lesões necróticas das plantas inoculadas com o SBMV / Abstract: The use of certain growth regulators in plants can result in the induction of resistance against attacks of some plant pathogens. This phenomenon is known as Systemic Acquired Resistance (SAR) and several mechanisms are involved in the induction of SAR.,among them are the Hypersensitive Reaction (HR), the increase in the activity of some enzymes like peroxidases (POX) and Phenylalanine ammonia-Iyase (PAL). Two different growth regulators (salicylic acid "SA" and a brassinosteroid "BR 16") were used in order to determine the induction of local resistance in bean plants (Phaseolus vulgaris L.) of cultivar Moruna (nc). Afier the application, the plants were mechanically inoculated with Southern bean mosaic virus (SBMV), genus Sobemovirus. The number of necrotic lesion was determined in the the primary leaves and the activity of the enzymes guaiacol peroxidases (g-POX) and Phenylalanine ammonia-Iyase (pAL) were also measured. There was a significant reduction in the number of necrotic lesions in the treated plants with both growth regulators and a significant increase in the activity ofthe g-POX, but there was no effect in the PAL activity. The effect ofthe application of SA and BR 16 in the induction of systemic resistance was verified through the application of these growth regulators in bean plants cultivar Jalo, inoculated with SBMV. The treatments promoted a significant reduction in the viral concentration in the SIDleaf, 28 days afier the inoculation of the primary leaves. The results indicated that the applications of SA and of the BR 16 promoted both local and systemic resistances. The increase in the activity of the guaiacol peroxidases, enzymes involved in the scavenning of reactive oxygen species, caused by the treatment with both growth regulators, suggested a contribution in the reduction of the number of necrotic lesions in the plants inoculated with SBMV. The use of SA and BR 16 did not change the activity of PAL, enzyme involved in the lignification process and in the mechanisms of plant defense against infections / Doutorado / Doutor em Biologia Vegetal

Auto-fluorescence emission of plant tissues can be a powerful reporter on plant biochemistry and physiology since it originates in substances inherent to primary or secondary metabolism. Plant bodies contain a plethora of intrinsic fluorescent compounds emitting practically all wavelengths of visible light. Moreover, the spectrum of fluorescent reporter signals was recently extended by a variety of fluorescent proteins that provide a new tool to mark whole cells or sub-cellular structures, study protein localization and monitor gene expression and molecule interactions. The imaging of such fluorescence signals reveals a possibility to acquire the information from as many as millions of points simultaneously, in vivo and in a non-invasive way thereby preserving integrity of cells and whole organisms. Imaging is particularly suited to visualize heterogeneity such as a localized immune response to invading pathogens. It can be applied both at macro- as well as micro-scales in two and three dimensions. The recent advancement in microscopy, the multi-photon microscopy, has made possible to monitor fluorescence signals, such as NAD(P)H fluorescence from intact leaf interior, that have been hidden to single-photon techniques.