Genetic dissection of the distinct origins and tissue-specific functions of abscisic acid during seed development in Arabidopsis thaliana.

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conclusionKarssen et al. (Planta 157:158-165, 1983) genetically dissected the maternal and zygotic origins of abscisic acid (ABA) by generating tissue-specific ABA deficiencies through crosses and demonstrated their distinct physiological functions. Abscisic acid (ABA) is a key regulator of seed development, controlling seed maturation, developmental arrest of embryos, induction of primary dormancy, and inhibition of germination. While its roles are now well established, this understanding stems from decades of genetic and physiological studies. A landmark contribution came from Karssen et al. (Planta 157:158-165, 1983), who used Arabidopsis to dissect the tissue-specific origins and functions of ABA during seed development. Their genetic strategy involved creating tissue-specific ABA deficiencies in either maternal or zygotic tissues. This approach revealed two distinct ABA peaks: the first derived primarily from maternal tissues and the second from zygotic tissues. ABA from distinct origins was linked to specific functions: zygotic ABA was essential for inducing primary dormancy, while maternal ABA played a minor role in dormancy but was critical for seed coat mucilage formation. These findings provided genetic evidence that ABA accumulation in seeds originated from different tissues, each contributing to distinct physiological roles. The work by Karssen et al. (Planta 157:158-165, 1983) established the foundation for current frameworks defining the role of ABA in seed development.