Título:	Analysis of maize photosyntheis parameters and whole plant oxidative damage under long-term drought.
Autoria:	LAVINSKY, A. O. MAGALHAES, P. C. ÁVILA, R. GOMES JR. C. C. CARNEIRO, N. P.
Afiliação:	PAULO CESAR MAGALHAES, CNPMS; NEWTON PORTILHO CARNEIRO, CNPMS.
Ano de publicação:	2015
Referência:	Advances in Crop Science and Technology, p. 1-6, 2015.
Conteúdo:	We test if maize maintain yield under long-term drought throught improvement of photosyntheis (A) coupled with up-regulation of the antioxidant system induced by increase in levels of abscisic acid (ABA). Four maize genotypes with constrasting drought tolerance: BRS1010 and 2B710 (sensitive) and DKB 390 and BRS1055 (tolerant) in two soil water levels, field capacity (FC) and water deficit (WD) were used. WD was applied at the pre-flowering stage for 12 days, and oxidative damage was measured as malondialdehyde (MDA) accumulation in whole plant. Plants from tolerant genotypes DKB390 and BRS1055 showed higher A and had no signal of oxidative damage compared to sensitive genotypes 2B710 and BRS1010 under WD, resulting in a higher yield attributes. For our surprising, it was dissociated from up-regulation of the antioxidant system ABA-mediated. In turn, plants from two sensitive genotypes under WD showed compared to FC consistent reduction of A due to mesophyll conductance (gm) limitation. Only WD plants from sensitive genotype BRS1010 presented leaf ABA levels increased related to its counterparts under FC; however, due to the inactivation of catalase activity the oxidative damage control was not effective, resulting a hardly MDA acumulation in both leaves and roots. The maize tolerance under long-term drought is linked to scape of gm decline.
Thesagro:	Milho Fotossíntese Ácido abscísico
Palavras-chave:	Mesofilo condutância Fotorrespiração Sistema antioxidante
Digital Object Identifier:	http://dx.doi.org/10.4172/2329-8863.S1-007
Tipo do material:	Artigo de periódico
Acesso:	openAccess
Aparece nas coleções:	Artigo em periódico indexado (CNPMS)