Data/hora: 11/06/2024 03:42:58

Provedor de dados: 	52	
País: 	Brazil	
Título: 	Enhanced biosynthesis of quercetin occurs as A photoprotective measure in Lycopersicon esculentum mill. under Acute UV-B exposure	
Autores: 	Shourie,Abhilasha; Tomar,Pushpa; Srivastava,Deepika; Chauhan,Rahul.	
Data: 	2014-06-01	
Ano: 	2014	
Palavras-chave: 	UV-B; Lycopersicon esculentum; Quercetin; Biomass; Pigments; Anthocyanins.	
Resumo: 	Lycopersicon esculentum respond to UV-B by enhanced synthesis of flavonoid quercetin, a strong antioxidant that helps the plants to well acclimatize to UV-B stress. Three weeks old plants of L. esculentum were subjected to acute UV-B irradiation for 20, 40 and 60 minutes daily until 28 days and analyzed for the morphological and biochemical changes. UV-B exposure for 40 and 60 minutes considerably affected the growth and biomass of L. esculentum. The leaves were deformed, developed chlorosis and abscised early as compared to the unexposed plants. Biomass declined by 35% and total chlorophyll decreased by 24.7% due to disintegration of chloroplasts. Enhancement was seen in the content of carotenoids, anthocyanins and total flavonoids by 15, 33.3 and 22.8%, respectively, which was attributed to the photoprotective role of these compounds as potential quenchers of excess excitation energy. Quercetin content decreased on UV-B exposure to 20 and 40 min, and thereafter increased significantly by 5.19% on 60 min of exposure. This pattern probably indicated that the over-expression of genes involved in its biosynthesis such as phenylalanine ammonia lyase (PAL), chalcone synthase (CHS), flavanone 3-hydroxylase (F3H) and dihydroflavonol 4-reductase (DFR) occurred only after certain threshold exposure (60 min), which could be the strategy for developing tolerance against UV-B stress in L. esculentum.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132014000300002	
Editor: 	Instituto de Tecnologia do Paraná - Tecpar	
Relação: 	10.1590/S1516-8913201401678	
Formato: 	text/html	
Fonte: 	Brazilian Archives of Biology and Technology  v.57 n.3 2014	
Fonte: 	info:eu-repo/semantics/openAccess