Regulates vegetative and gynoecium development (PubMed:16356489). In concert with HUA2, antagonizes FLK by positively regulating FLC probably at transcriptional and post-transcriptional levels, and thus acts as a negative regulator of flowering (PubMed:19576878). Interacts with HUA1 and HEN4. Detected in roots, shoots, leaves, flowers and fruits. In seedlings, expressed in leaf primordia and young developing leaves. Progressively circumscribed to the adaxial side of developing leaves to become restricted to the veins in fully expanded leaves. In roots, confined to the vasculature. Present in floral buds and young developing flower organs. Accumulates in perianth organs and stamens before being restricted to the vascular system in later postanthesis stages. Strong expression throughout the young pistil. Disappears from the apical stigma during postanthesis fruit maturation. Detected in the style until later stages in fruit development, mainly in style vasculature, but progressively fades away from most of the ovary region. Subtle morphological alterations in pep-2 and pep-4 such as leaf alterations, phyllotactic errors and sporadic presence of small fruits with multiple valves. Occasional asymmetry in valve growth and unfused carpels (PubMed:16356489). Rescues the flk mutant late-flowering phenotype with a concomitant decrease in FLC RNA levels (PubMed:19576878).