Forms a channel through the mitochondrial outer membrane that allows diffusion of small hydrophilic molecules. The channel adopts an open conformation at low or zero membrane potential and a closed conformation at potentials above 30-40 mV. The open state has a weak anion selectivity whereas the closed state is cation-selective (By similarity). Involved in plant growth and development at the vegetative and reproductive stages. Is important for leaf and pollen development and mitochondrial membrane potential steady state. May be involved in disease resistance. Also localized in other unidentified cellular compartments. Widely expressed. By the bacterial pathogen P.syringae pv. tomato. Consists mainly of membrane-spanning sided beta-sheets. Dwarf plants with lesion mimic phenotype and increased expression of the pathogenesis-related genes PR1, PR2 and PR5. Delayed flowering, impaired development of anthers and short siliques with sterile seeds. Belongs to the eukaryotic mitochondrial porin (TC 1.B.8.1) family.