Catalyzes the 13-hydroxylation of gibberellins (GAs). Determines the ratio of GA4 and GA1. Converts GA12 into GA53. Highly expressed in spikelet and uppermost internode. Detected in shoots, roots, leaves and anthers. Up-regulated by bioactive gibberellins. No visible phenotype and no change in the levels of 13-OH GAs; due to the redundancy with CYP714B2. Cyp714b1 and cyp714b2 double mutants have decreased levels of 13-OH GAs, increased levels of 13-H GAs, including GA4, and longer uppermost internode. Overexpression of CYP714B1 in a heterologous system causes semi-dwarfism and increased 13-OH GAs content. Belongs to the cytochrome P450 family. Truncated N-terminus. Truncated N-terminus.