Análise de genes PGs e PGIPs associados às interações planta-patógeno

Abstract

Polygalacturonases (PGs) are enzymes secreted by phytopathogenic fungi that degrade the plant cell wall, facilitating tissue colonization and the progression of infection. In response, plants produce polygalacturonase-inhibiting proteins (PGIPs), which inhibit PG activity, hindering invasion and increasing resistance against pathogens. In order to gain a deeper understanding of the complex interaction between PGIPs and PGs, as well as plant defense mechanisms, the present study was conducted in three stages. Initially, 39 PGIPs from 30 plant species were characterized with respect to phylogeny, protein properties, subcellular localization, conserved domains and motifs, gene structure, and cis-elements. The results revealed the distribution of PGIPs according to species taxonomy, their predominance in the extracellular environment, the presence of three conserved domains, the absence or presence of few introns, and the abundance of the TATA-box and CAAT-box cis-elements. These findings contribute to understanding the role of PGIPs in plant defense. The second stage involved evaluating the effectiveness of the bean genes PvuPGIP1 and PvuPGIP2 in inhibiting Sclerotinia sclerotiorum in tobacco through Agrobacterium-mediated transient genetic transformation. The results demonstrated a significant defensive effect of these genes during the first three days after inoculation, reinforcing the potential of PGIPs in controlling phytopathogens. Finally, 115 fungal PGs from the GH28 family were characterized. The proteins were classified into five phylogenetic groups, and their protein properties, subcellular localization, and conserved motifs were analyzed. The results revealed the presence of four main conserved motifs and contributed to understanding the interaction between PGs and PGIPs, providing a foundation for future research related to plant disease control.