Involved in auxin signaling pathway. Required for embryo development and meristem organization. Functions in the auxin pathway, integrating auxin signaling in the organization and maintenance of the shoot apical meristem (SAM) and root apical meristem (RAM). During early phases of embryogenesis, expressed in all the cells of the embryo proper and the suspensor until the 32-cell embryo stage. At the heart stage, expression completely disappears in the suspensor, but remains in the embryo proper. After germination, expressed in shoot apical meristem (SAM), leaf primordia, root apical meristem (RAM), and lateral root primordia. Temperature-sensitive phenotype. Defective in embryo development and embryo lethality when grown at 22 degrees Celsius. Embryo lethality phenotype rescued when grown at 29 degrees Celsius. Germination of temperature-rescued pcn mutant seeds give plants with small and narrow-shaped leaves, abnormal leaf vein patterns, altered flowering organs and defects in the root apical meristem (RAM).