Banca de DEFESA: DAISY SOTERO CHACON
Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : DAISY SOTERO CHACON
DATE: 27/03/2024
TIME: 14:00
LOCAL: Link de acesso para videoconferência: https://meet.google.com/qqz-fghf-bkt
TITLE:
Erythrina velutina Willd. alkaloids : piecing biosynthesis together from transcriptome analysis and metabolite profiling of seeds and leaves
KEY WORDS:
Erythrina velutina; transcriptome; metabolome; elicitation; biosynthesis; alkaloids; flavonoids; caatinga.
PAGES: 273
BIG AREA: Ciências da Saúde
AREA: Farmácia
SUMMARY:
The study of plants is under increasing transformation due to the availability of molecular and
bioinformatics tools to understand metabolism and point out potential sources of new bioactive
chemical entities with pharmaceutical interest. In this scenario, Erythrina velutina stands out
as a medicinal plant found in the northeast region of Brazil, mainly in the Caatinga biome. This
plant has a remarkable ability to produce alkaloids and flavonoids, which are the main secon
dary metabolites of the genus and are often associated with pharmacological activities, such
as modulators of the central nervous system (with antidepressant and anxiolytic effects) and
anti-inflammatory action. Although some natural products (NP) have been effective as a source
of new drugs, the pharmaceutical industry still faces challenges in the identification and opti
mized production of these compounds and this has led to a reduction in interest in NP-based
drugs. In order to minimize these gaps, this study aims to integrate molecular and chemical
data to investigate the biosynthesis of the main metabolites present in E. velutina under three
aspects: to evaluate the metabolic production in plants collected in natural habitat (Caatinga)
and in cultivated plants submitted to different elicitors (ii); identify reference genes that norma
lize RT-qPCR tests for the species (ii) and evaluate the expression of target genes responsible
for the production of alkaloids and flavonoids with bioactive potential (iii). The study focuses
on transcriptome, proteome and metabolome data obtained from samples collected in their natu
ral habitat, in addition to seedling cultivation subjected to environmental stresses (temperature,
UV, water stress, salt stress and mechanical damage) and phytohormones (methyljasmonate ,
salicylic acid, nitric oxide and abscisic acid). As a result, the predominant flavonoids observed
were flavones, isoflavones, and flavonols, along with several isoquinoline alkaloids from both
dienoids and alkenoids. Transcriptome analysis revealed the presence of enzymes involved in
the flavonoid and alkaloid biosynthesis pathways, including those differentially expressed, such
as EvCHI, EvIF7GT, EvCHS, EvCOR, EvNMT and EvODM. Among the treatments tested, the
most significant accumulation of metabolites occurred in response to NO, MeJA, water stress
and heat, while ABA caused the least pronounced effect. For normalization of RT-qPCR assays,
EvCSTF64, EvRAB7, EvNLE, EvUPF and EvARP4 were identified as the most stable reference
genes, while EvNADH and EvPBL27 exhibited lower stability. These genes serve as reliable re
ference points to ensure accurate normalization of gene expression data in subsequent analyses.
The results pointed to NO as crucial in increasing the expression of CHI and the amounts of
isoflavones noted. Drought stress negatively affected early precursors of the Erythrina alkaloid
pathway, while MeJA had the opposite effect. Exposure to heat increased alkaloid concentra
tions. This study will contribute to the understanding of the secondary metabolism of plants
in the semi-arid/xeric environmental conditions, characteristic of the Caatinga region. In addi
tion, may help to improve the production of bioactive molecules in the species and to value a
plant from the Caatinga of Rio Grande do Norte as a source of compounds with pharmaceutical
potential. This research represents the first step towards guiding the management for optimaltarget metabolite production in E. velutina.
COMMITTEE MEMBERS:
Interno - 1492900 - CICERO FLAVIO SOARES ARAGAO
Interno - 2276354 - LEANDRO DE SANTIS FERREIRA
Externo à Instituição - MASSUO JORGE KATO - USP
Presidente - 1871916 - RAQUEL BRANDT GIORDANI
Externo à Instituição - WAGNER LUIZ ARAUJO - UFV