Fig. 7: Model of Gladiolus corm development regulated by abscisic acid and gibberellin.

ABA positively regulates corm development by enhancing GhSUS2 expression and starch synthesis. Repressing GhSUS2 decreases starch content and leads to the formation of small corms. GA has the opposite effect on GhSUS2 expression and starch synthesis and causes a decrease in the number and size of cormels. Silencing GhNCED or GhGA20ox in corms had opposite effects on GhSUS2 expression, starch accumulation and corm development