Gibberellin A4 is a plant hormone originally isolated from G. fujikuroi that has plant signaling and growth stimulatory activities.1 Gibberellin A4 is found in the micropylar endothelium cells of Arabidopsis maternal seed tissue and triggers suspensor programmed cell death (PCD) in the embryo.2 It increases hypocotyl, but not radicle, growth of cucumber seedlings when used at concentrations ranging from 6-100 µM.3 Gibberellin A4 also increases flowering in apple trees when applied post-flowering in the previous year.4
1.Takahashi, N., Seta, Y., Kitamura, H., et al.A new gibberellin, gibberellin A4Bull. Agri. Chem. Soc. Japan21(6)396-398(1957) 2.Shi, C., Luo, P., Du, Y.-T., et al.Maternal control of suspensor programmed cell death via gibberellin signalingNat. Commun.10(1)3484(2019) 3.Halevy, A.H., and Cathey, H.M.Effects of structure and concentration of gibberellins on the growth of cucumber seedlingsBot. Gaz.122(1)63-67(1960) 4.Looney, N.E., Pharis, R.P., and Noma, M.Promotion of flowering in apple trees with gibberellin A4 and C-3 epi-gibberellin A4Planta165(2)292-294(1985)