Banca de QUALIFICAÇÃO: JULIANA GABRIELA SILVA DE LIMA
Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.DISCENTE : JULIANA GABRIELA SILVA DE LIMA
DATA : 24/08/2016
HORA: 09:00
LOCAL: Sala Carnaúba
TÍTULO:
Is a hydrogen peroxide burst necessary to seed-to-seedling transition in Carthamus tinctorius L.? Insights from drought and salinity stresses.
PALAVRAS-CHAVES:
Functional transition, catalase, ascorbate peroxidase, isocitrate lyase, malate synthase.
PÁGINAS: 24
GRANDE ÁREA: Ciências Biológicas
ÁREA: Bioquímica
RESUMO:
Seed-to-seedling transition in oilseeds is a crucial stage of development when ocurr the change of autotrophic to heterotrophic metabolism. This phase conversion is characterized by the transformation of the glyoxysome into leaf peroxisomes and depends of enzymatic, transcriptional and redox complex regulation. As in other physiological processes, the photosynthetic establishment can also be severely affected by increases in ions concentrations or water scarcity. However, studies generally report metabolic changes throughout the development under stress applied only at the time of sowing. Therefore, to investigate the physiological and metabolic alterations specifically during seed-to-seedling transition is necessary that the treatment application is carried out only during this phase. So, safflower seeds were germinated in water for 30 h and only after this subjected to drought (PEG- induced) and salt stress with the purpose of evaluating their phenological and physiological responses and to elucidate the activity of CAT, APX and SOD antioxidant systems in oxidative parameters and their integration with glioxissomal metabolism. We found that the seedlings subjected to the stress suffered losses in the phenological and physiological aspects evaluated, although having lower H2O2 and MDA-TBA contents, high APX activity and expression, when compared to the controls, and also high ICL and MLS expression. This leads us to believe that the seed-to-seedling transition is directly dependent on high levels of H2O2 and that APX system is closely linked to the maintenance of the photosynthetic establishment in seedlings of this species.
MEMBROS DA BANCA:
Presidente - 1880243 - DANIEL CARLOS FERREIRA LANZA
Externo ao Programa - 1516627 - JULIANA ESPADA LICHSTON
Interno - 1453487 - KATIA CASTANHO SCORTECCI