Banca de QUALIFICAÇÃO: JOSE DEMETRIOS SANTOS NASCIMENTO
Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.DISCENTE: JOSE DEMETRIOS SANTOS NASCIMENTO
DATA: 10/08/2015
HORA: 09:00
LOCAL: Sala Carl Peter von Dietrich - Depto. de Bioquímica - CB/UFRN
TÍTULO:
Coordinated Modulation of Root Growth and Reserve Mobilization by Glutamate During Seedling Establishment in Sunflower
PALAVRAS-CHAVES:
Helianthus annuus L.; Metabolite partitioning; Root architecture; Source-sink relation; Sugar signalling
PÁGINAS: 27
GRANDE ÁREA: Ciências Biológicas
ÁREA: Bioquímica
SUBÁREA: Metabolismo e Bioenergética
RESUMO:
Sunflower seedlings grown in vitro were exposed to different exogenous sources of organic and inorganic N to investigate if these compounds could modulate reserve mobilization by acting as signals of the source-sink relation. Only glutamate was able to simultaneously inhibit root growth, delay reserve mobilization, and change metabolite partitioning. Primary root growth and lateral root emergence and elongation were severely inhibited in the presence of glutamate and these effects were reproduced by asparagine. The mobilization of both C and N reserves was affected when glutamine and glutamate were added to the culture medium, but oil degradation was less affected than starch and storage protein hydrolysis. As the amino acid content was not changed and the sugar content was increased in the cotyledons of glutamate-treated seedlings, it seems that sugars, instead of amino acids, played a part as signals of the source-sink relation. Considering that the activity of enzymes involved in reserve degradation was not decreased in a coordinated fashion by glutamate, the simultaneous delay of oil, starch, and storage protein mobilization seems a consequence of intricate mechanisms affected by the source-sink relation during seedling establishment in sunflower.
MEMBROS DA BANCA:
Presidente - 1453487 - KATIA CASTANHO SCORTECCI
Interno - 1880243 - DANIEL CARLOS FERREIRA LANZA
Interno - 1149356 - ELIZEU ANTUNES DOS SANTOS