Skip to main content
. 2021 Oct 30;22(21):11804. doi: 10.3390/ijms222111804

Figure 1.

Figure 1

Regulatory phytohormone networks in seed dormancy and seed germination. Three major phytohormones, including auxin, abscisic acid (ABA), and gibberellin (GA), are key players in seed dormancy and germination. Mature seeds are dormant and contain a high level of ABA and a low level of GA. Several transcription factors (ABI4, DDF1, OsAP2-39, AP2, and CHO1) are involved in the seed dormancy stage by positively regulating (+) the accumulation of ABA and decreasing the GA content. While seed dormancy is broken, the seed becomes nondormant and the initiation of germination can start. At this stage, the ABA/GA balance is kept by positive and negative regulation signals of almost all other phytohormones, including ethylene (ET), brassinosteroids (BRs), jasmonic acid (JA), salicylic acid (SA), cytokinins (CTKs), and strigolactones (SLs). Here, transcription factors including ARFs, MYB96, ABI3, ABI4, and ABI5 regulate ABA biosynthesis by interacting with CYP707A1 and CYP707A2, while GA-negative regulation (-) is ensured by DELLA genes. The balance is constantly maintained until the seed emergence step.