Transcription activator (PubMed:24278028). Binds to 5'-CAACTGTC-3' and/or 5'-TAACAAA-3' motif in target gene promoter to promote their expression (By similarity). Together with MYB101 and MYB120, functions as a male factor that controls pollen tube-synergid interaction in fertilization. Required for pollen tube growth arrest and sperm cell release in the female gametophyte, probably via the regulation of pollen tube-specific gene expression (PubMed:24278028, PubMed:23791732). Detected in the vegetative nucleus of pollen tubes. Accumulates in pollen grains and pollen tube (PubMed:14500793, PubMed:23791732, PubMed:24278028). Mostly expressed in mature pollen grains, and, to a lower extent, in inflorescences and siliques (PubMed:24278028). Accumulates in the pollen tube nucleus during pollen tube growth through the pistil. The triple mutant myb97 myb101 myb120 is impaired in pollen tube growth arrest and subsequent sperm cell release in the female gametophyte thus leading to a drastically reduced fertility. Altered pollen tube-specific gene expression. Extended C-terminus.