RESUMO
Environmental biotic stress factors act continuously on plants, through multiple molecular interactions that eventually lead to the establishment and progress of symbiotic or pathogenic complex interactions. Proteins and peptides play noteworthy roles in such biological processes, usually being the main effectors since the initial recognizing and elicitor functions until the following transduction, gene regulation and physiological responses activities. Ranging from specific regulators to direct antimicrobial agents, plant or pathogen proteins and peptides comprise the arsenal available to each side in this biological war, resulting from the genetic coding potential inherited by each one. Post-translational research tools have widely contributed with valuable information on how the plant proteome works to achieve, maintain and adjust plant immunity in order to properly cope with the challenging pathogenic derived proteomes. These key proteins and peptides have great biotechnological potential since they represent distinctive features of each pathogen group (fungi, bacteria, viruses and other) in response to molecules of defense of host plants.
Assuntos
Peptídeos Catiônicos Antimicrobianos/imunologia , Resistência à Doença/genética , Interações Hospedeiro-Patógeno , Doenças das Plantas/imunologia , Proteínas de Plantas/imunologia , Plantas/genética , Peptídeos Catiônicos Antimicrobianos/biossíntese , Peptídeos Catiônicos Antimicrobianos/genética , Bactérias/crescimento & desenvolvimento , Bactérias/patogenicidade , Fungos/crescimento & desenvolvimento , Fungos/patogenicidade , Regulação da Expressão Gênica de Plantas/imunologia , Doenças das Plantas/genética , Imunidade Vegetal/genética , Proteínas de Plantas/biossíntese , Proteínas de Plantas/genética , Plantas/imunologia , Plantas/microbiologia , Plantas/virologia , Plantas Geneticamente Modificadas , Proteômica/métodos , Sesquiterpenos/imunologia , Sesquiterpenos/metabolismo , Transdução de Sinais , Estresse Fisiológico/genética , Estresse Fisiológico/imunologia , Vírus/crescimento & desenvolvimento , Vírus/patogenicidade , FitoalexinasRESUMO
Biological nitrogen fixation from the legume-rhizobia symbiosis is one of the main sources of fixed nitrogen on land environments. Diazotrophic bacteria taxonomy has been substantially modified by the joint use of phenotypic, physiological and molecular aspects. Among these molecular tools, sequencing and genotyping of genomic regions such as 16S rDNA and repetitive conserved DNA regions have boosted the accuracy of species identification. This research is a phylogenetic study of diazotrophic bacteria from sabiá (Mimosa caesalpiniifolia Benth.), inoculated with soils from five municipalities of the Brazilian Northeast. After bacterial isolation and morphophysiological characterization, genotyping was performed using REP, ERIC and BOX oligonucleotides and 16S rDNA sequencing for genetic diversity identification. A 1.5b Kb fragment of the 16S rDNA was amplified from each isolate. Morphophysiological characterization of the 47 isolates created a dendrogram, where isolate PE-GR02 formed a monophyletic branch. The fingerprinting conducted with BOX, ERIC and REP shows distinct patterns, and their compilation created a dendrogram with diverse groups and, after blasting in GenBank, resulted in genetic identities ranging from 77 to 99 % with Burkholderia strains. The 16S rDNA phylogenetic tree constructed with these isolates and GenBank deposits of strains recommended for inoculant production confirm these isolates are distinct from the previously deposited strains, whereas isolates PE-CR02, PE-CR4, PE-CR07, PE-CR09 and PE-GE06 were the most distinct within the group. Morphophysiological characterization and BOX, ERIC and REP compilation enhanced the discrimination of the isolates, and the 16S rDNA sequences compared with GenBank confirmed the preference of Mimosa for Burkholderia diazotrophic bacteria.