By analyzing a Jatropha genome, NF-YB-encoding genes of SEQ ID NOs: 1 to 11, fragments of NF-YB-encoding genes of SEQ ID NOs: 12 and 13, and genes relating thereto were found. By transforming Jatropha with these NF-YB-encoding genes and the like, it is possible to overexpress a NF-YB polypeptide and so on, and to significantly improve the productivity of protein synthesis involved by the NF-YB polypeptide, and to significantly improve the dry stress resistance, for example. As a result, it is possible to create dry stress resistant Jatropha capable of ensuring high growth even under water deficient conditions.