The present invention provides genes and proteins having possibilities to generate plants having tolerance against excessive boron, which can confer a boric acid tolerance to organisms. 5 types of genes that can confer a boric acid tolerance to yeast, such as AtPAB2, AtRBP47c', AtRPS20B, AtMYB13 and AtMYB68, AtRBP45a, AtRBP45b, AtRBP45c, AtRBP45d, AtRBP47a, AtRBP47b, AtRBP47c, AtUBP1a, AtUBP1b and AtUBP1c which were found by expressing several genes of higher plant Arabidopsis thaliana in yeast that is a organism model of eukaryote. Further, a key to the toxicity mechanism of boric acid exists in the specific inhibition of splicing, and a gene related to enhancement of splicing efficiency also confers a boric acid tolerance.