Seed filling, a phase defined by morphological, cellular, and metabolic changes in the endosperm and embryo that coincide with rapidly increasing storage reserves, determine seed development and storage reserve accumulation. Although diverse functioning abscisic acid (ABA) responsive factors were identified in plants, relatively limited information is known on plant hormone abscisic acid (ABA) responsive genes involved in storage reserve accumulation during seed filling.
Umashankar Chandrasekaran of Xishuangbanna Tropical Botanical Garden (XTBG) and his teachers conducted a study to report the application of phytohormone ABA as an exogenous factor for the improvement of storage reserve accumulation with a focus on the complex interaction of pathways associated with seed filling. The study was focused on analyzing the effect of exogenous ABA signaling on storage reserve accumulation during castor bean (Ricinus communis L.) seed filling at both physiological as well as at transcriptional level.
Their study showed that the application of exogenous ABA enhanced the storage reserve accumulation together with the global regulatory changes at transcriptional level towards seed filling. The findings provided a comprehensive coverage to discover many known genes of several major metabolic pathways substantially responsive to exogenous ABA signaling, which also serve as a potential contribution to available sequence resources for castor bean.
From their results and diverse assessment, the researchers concluded that ABA exhibited a stage specific and species dependent functioning when applied as an external supplement during seed filling process under in vitro conditions.