Profile of antioxidant content upon developing of Sorghum bicolor seeds

Abstract

The early and slight increase in oxygen uptake of the sorghum axes defines germination phase I, whereas germination phase II is characterized by the assumption of a marked rate of increase in both oxygen uptake and seed weight. The cellular non-enzymatic antioxidant capacity was determined during the early imbibition period. Over the initial 18 h of imbibition ascorbate content in sorghum seeds was not significantly affected, however, as soon as an active metabolism is established the ascorbate content in the seeds increased significantly. The same profile was observed for the total thiol content in sorghum seeds during the initial 48 h of development. Both α- and γ-tocopherol content in sorghum seeds significantly increased up to 24 h of imbibition and no further changes were detected between 24 and 48 h of incubation. The 3-desoxyanthocyanidin apigeninidin was isolated from sorghum imbibed up to 48 h and high performance liquid chromatography (HPLC) chromatograms of the isolated pigment was recorded. Apigeninidin content in sorghum seeds was significantly increased (2-fold) upon imbibition. Taken as a whole, the data presented here strongly suggest that a complex and integrated antioxidant system is triggered during the early stages of sorghum seeds development to limit oxidative-dependent deterioration at this critical period for plant survival.