Has antifungal activity against P.betae and F.dahliae. May be involved in disease resistance in tomatoes and/or have a possible role in fruit development and ripening. Or soluble fractions of cytoplasmic organelles, except mitochondria and plastids. Highest levels of both isoforms found in the outer pericarp, with smaller amounts in the inner pericarp. NP24 I is low in green tomatoes and it increased substantially during ripening, with the largest increase occurring between the pink and red stages. NP24 II is relatively high in green tomatoes and it increased somewhat as the fruit turned pink, but not during further ripening. By salt stress or by viroids. Belongs to the thaumatin family.