Antioxidants from maize seeds and accelerated ageing

Abstract

Seed deterioration is expressed as the loss of viability, vigour and quality during ageing The major causes of seed deterioration refer to free radical-mediated lipid peroxidation, enzyme inactivation or protein degradation, disruption of cellular membranes and damage to genetic integrity Accelerated ageing (AA) is a simple method for studying the mechanisms of deterio- ration over short periods In order to estimate the deterioration rate, seeds of four maize geno- types were exposed to accelerated ageing for different time points (three and six days of AA) In parallel, the same genotypes were evaluated regarding the content of total phenolics, phenolic acids, flavonoids and anthocyanins, as well as regarding total antioxidant capacity Compared to non-stressed seeds, ageing was evidenced by decreased germination energy (48 9%), a total number of seedlings (40 8%) and seedlings growth (70 0% for root length, 44 0% and 10 5% for root and shoot fresh weight, 5 0% for seed rest fresh weight, 12 0% and 11 5% for root and shoot dry weight, 15 3% for seed rest dry weight, respectively), as well as by an increased number of abnormal seedlings (22 0%) Correlation analysis revealed that higher content of total phenolics, flavonoids and anthocyanins contributed to a higher radical scavenging activity, which was re- flected through a lower level of deterioration rate, both regarding the energy of germination and overall seedling performance.

Propadanje semena se ogleda u gubitku životne sposobnosti, energije i kvaliteta Dejstvo slo- bodnih radikala dovodi do peroksidacije lipida, inaktivacije enzima, degradacije proteina, raza- ranja ćelijskih membrana i oštećenja genetičkog materijala, i smatra se glavnim uzrokom propa- danja semena Ubrzano starenje, kao metod, omogućava proučavanje mehanizama propadanja semena u kratkom vremenskom periodu Za procenu stepena propadanja, seme četiri genotipa kukuruza je izloženo tretmanu ubrzanog starenja u trajanju od tri i šest dana Uporedo sa ovim, kod istih genotipova je ispitivan sadržaj ukupnih fenola, fenolnih kiselina, flavonoida i antoci- jana, kao i ukupni antioksidativni kapacitet Poređenjem sa nestresiranim semenom (kontrola), starenje je rezultiralo padom energije klijavosti (48,9%), smanjenjem ukupnog broja klijanaca (40,8%), smanjenjem rasta klijanaca (70,0% za dužinu korena, 44,0% i 10,5% za svežu masu ko- rena i izdanka, 5,0% za svežu masu semenog ostatka, 12 0% i 11 5% za suvu masu korena i iz - danka, 15 3% za suvu masu semenog ostatka, respektivno), kao i povećanjem broja nenormalnih klijanaca (22,0%) Korelacionom analizom je utvrđeno da je povećani sadržaj ukupnih fenola, flavonoida i antocijana doprineo većoj sposobnosti gušenja slobodnih radikala, reflektujući se kroz smanjen stepen propadanja semena, kako u pogledu energije klijavosti, tako i u pogledu ukupne performanse klijanca.