Banca de DEFESA: MARLON ENRIQUE LOPEZ TORRES

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE: MARLON ENRIQUE LOPEZ TORRES
DATA: 30/07/2021
HORA: 09:00
LOCAL: Videoconferência pelo Google Meet
TÍTULO:

Regulation of coffee flowering time: Hormonal Crosstalk and transcriptomic analysis in flower development and anthesis

PALAVRAS-CHAVES:

Flowering, LHT1 Transporter, ACO, Acauã, Oerias, Semperflorens, ABA, Ethylene

PÁGINAS: 60
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
RESUMO:

Coffee flowering is regulated by endogenous and environmental stimulus and occurs once plants are rehydrated after a period of water deficit period. In this study, the effect of exogenous application of 1-aminocyclopropane-1-carboxylic acid (ACC) as a modulator in coffee anthesis was evaluated. Also, the evolution of Abscisic Acid (ABA), ethylene, ACC content, ACC oxidase (ACO) activity, and expression analysis of the LHT1 (Lysine Histidine Transporter 1) transporter, in roots, leaves and, flower buds from coffee cultivars (Coffea arabica L. cv Oeiras, Acauã, and Semperflorens) cultivated under field conditions were evaluated. These analyses were carried out at three different times: at the end of the rainy period (May 18th), dry period (August 18th), and re-watering period (August 28th). Leaf and bud ABA content increased during the dry period in each coffee genotype, decreasing in Oeiras and Semperflorens and increasing in both tissues for Acauã in the re-watering period. Ethylene levels decreased from rainy to re-watering period, similar to the ACO activity reduction observed in the same period. Remarkably, ACC increased in all tissues from the three coffee cultivars in the re-watering period just before anthesis. In a second experiment, covering plants under field conditions confirmed the importance of water in the coffee anthesis process, as the same pattern of the hormone evolution was observed when compared to the first experiment. A third field experiment of exogenous application of ACC confirmed the modulation of this non-protein amino acid in coffee anthesis, since treatments with ACC showed a higher number of flower buds in G6 stage. Finally, LHT1 expression was higher in roots and flower buds in the re-watering period and no differences were found in leaves for field experiment I and II. An opposite ABA-ACO-ethylene interaction in coffee flower buds was observed, favoring the ACC level to be increased, and an intercellular ACC transport among leaves, buds, and roots is involved as a modulator in coffee anthesis.

MEMBROS DA BANCA:
Interno - VAGNER AUGUSTO BENEDITO - UFLA (Membro)
Interno - PAULO EDUARDO RIBEIRO MARCHIORI (Suplente)
Externo à Instituição - MANUEL JAMILENA QUESADA - UAL (Membro)
Externo à Instituição - LÁZARO EUSTÁQUIO PEREIRA PERES - ESALQ (Membro)
Externo à Instituição - DAPENG ZHANG - USDA (Membro)
Presidente - ANTONIO CHALFUN JUNIOR (Membro)
Externo à Instituição - ANDRÉ ALMEIDA LIMA - FIOCRUZ-MG (Suplente)