PROBLEM TO BE SOLVED: To avoid photooxidation injury, promote the growth of plants and increase the production of foods by administering a low-molecular organic acid (salt) to the plants. SOLUTION: A low-molecular organic acid (salt) such as potassium formate sodium formate and ammonium formate is administered to plants to induce the enzyme activity of a formate dehydrogenase and promote the growth of the plants, or a low-molecular alcohol such as methanol is administered to the plants to avoid photooxidation injury and promote the growth of the plants. Furthermore, (a) a DNA fragment comprising a base sequence represented by formula II and derived from a rice plant formate dehydrogenase or (b) a DNA fragment comprising the base sequence represented by formula II in which a part of the DNA fragment (a) is deleted, substituted or added, derived from the rice plant formate dehydrogenase and capable of encoding (A) a polypeptide comprising an amino acid sequence represented by formula I and derived from the rice plant formate dehydrogenase or (B) a polypeptide comprising the amino acid sequence represented by formula I in which a part of the component A is deleted, substituted or added, having actions of producing carbon dioxide using formic acid as a substrate and derived from the rice plant formate dehydrogenase is preferably transduced into the plants to excessively express the rice plant formate dehydrogenase and promote the growth of the plants.
