Tobacco (Nicotiana tabacum) Ca2+-dependent protein kinase 1 (NtCDPK1) is involved in feedback regulation of the plant hormone gibberellin through the phosphorylation of the transcription factor. REPRESSION OF SHOOT GROWTH (RSG). Previously. Ser-6 and Thr-21 were identified as autophosphorylation sites in NtCDPK1. https://www.chiggate.com/