Banca de QUALIFICAÇÃO: MARIA CLARA CARLI

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE: MARIA CLARA CARLI
DATA: 21/06/2024
HORA: 08:00
LOCAL: Google Meet - meet.google.com/pbe-ivir-ted
TÍTULO:

Genome-wide analysis of PGIP genes associated with plant resistance to diseases

PALAVRAS-CHAVES:

Polygalacturonase inhibitory protein, polygalacturonase, leucine-rich repeats,
phytopathogens, plant-pathogen interaction.

PÁGINAS: 25
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Fitotecnia
ESPECIALIDADE: Melhoramento Vegetal
RESUMO:

Polygalacturonase inhibitory proteins (PGIP) produced by plants belong to families
of proteins with leucine-rich repeats (LRR). In the presence of polygalacturonases (PG)
enzymes secreted by phytopathogens during the infection of plant tissue, cell wall degradation
occurs with the release of oligogalacturonide (OG) fragments, which are accumulated in the
medium. These OGs signal to the plant a demand for the production of PGIPs, which inhibit
PGs and, therefore, infection and colonization by the fungus. Acting as a plant defense
mechanism and given the possibility of a strategy that allows the prediction or increase of
plant resistance to diseases, research on this topic is highly relevant for genetic improvement.
In this study, a genome-wide analysis was performed to characterize PGIP genes and proteins
from different species. From the selection of PGIPs published in the literature with confirmed
effects regarding the inhibition of fungal PGs in plants, amino acid sequences, nucleotides,
and CDS regions of PGIP genes from 30 plant species were obtained. Of this total, 11
available Putative Promoter Regions (PPR) were analyzed. To this purpose, the Phytozome
and NCBI databases were used to obtain the sequences. With this information, multiple amino
acid sequences were aligned and a phylogenetic tree was constructed, which made it possible
to evaluate the homology between the 38 PGIPs, using the PGIP of a bryophyte (Ceratodon
purpurus) as an outgroup. Based on the classification order of PGIPs by the phylogenetic tree,
the characterization of the biochemical properties of the proteins, the number of amino acids,
molecular weight, isoelectric point and percentage composition of amino acids, protein
domains, structural motifs, and the subcellular location was carried out. Among the
highlights, PGIPs are rich in leucine and have 3 conserved functional domains, LRRNT_2,
LRR_4, and LRR_8. In general, PGIPs are located in the extracellular space, but NtaPGIP1,
NtaPGIP2, and PpePGIP1 were predicted for the intracellular space, with the first 2 for
mitochondria and the last for the nucleus. Three structural motifs, 2, 4, and 5, stood out for
being conserved in all 38 proteins analyzed. Regarding the genes structure that encodes
PGIPs, it was found that only 6 PGIPs have introns. In the study of promoters, 73 cis-
elements were identified, the most frequent being those considered essential for mRNA
transcription, such as the TATA-box (36.4%), the CAAT-box (28.78%), and the AT ~TATA -
box (3.61%). Together, the results of this study increased the level of enlightenment about
PGIPs, providing important insights into their potential to act in different pathosystems.

MEMBROS DA BANCA:
Presidente - WELISON ANDRADE PEREIRA (Membro)
Externo à Instituição - RENATO COELHO DE CASTRO VASCONCELLOS - N/A (Membro)
Externo ao Programa - FLAVIO HENRIQUE VASCONCELOS DE MEDEIROS - DFP/ESAL (Membro)
Interno - EVANDRO NOVAES (Membro)
Externo ao Programa - ANTONIO CHALFUN JUNIOR - DBI/ICN (Suplente)