02149naa a2200253 a 450000100080000000500110000800800410001902400520006010000200011224501280013226000090026052013680026965000220163765000180165965000100167765300220168765300260170965300250173570000210176070000150178170000200179670000200181677300590183620355522016-02-24       2015    bl uuuu     u00u1 u    #d7 ahttp://dx.doi.org/10.4172/2329-8863.S1-0072DOI1 aLAVINSKY, A. O.  aAnalysis of maize photosyntheis parameters and whole plant oxidative damage under long-term drought.h[electronic resource]  c2015  aWe 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.  aÁcido abscísico  aFotossíntese  aMilho  aFotorrespiração  aMesofilo condutância  aSistema antioxidante1 aMAGALHAES, P. C.1 aÁVILA, R.1 aGOMES JR. C. C.1 aCARNEIRO, N. P.  tAdvances in Crop Science and Technology, p. 1-6, 2015.