Application of brassica napus BnaSPT3 gene in promoting growth of pods of dicotyledons

The invention discloses an application of a brassica napus BnaSPT3 gene in promoting growth of pods of dicotyledons. A base sequence of the brassica napus BnaSPT3 gene is shown as SEQ ID NO.1. The application comprises the following steps: (1) linking the brassica napus BnaSPT3 gene into a plant expression vector, so that a recombinant expression vector is constructed; and (2) transforming the recombinant expression vector into a recipient plant. The invention also discloses the recombinant expression vector containing the brassica napus BnaSPT3 gene and a transformant containing the recombinant expression vector. According to the application provided by the invention, by cloning the brassica napus BnaSPT3 gene, implementing genetic transformation in arabidopsis thaliana and through excessive expression of the exogenous brassica napus BnaSPT3 gene, the size of arabidopsis thaliana spt mutant pods can be obviously increased, and the number of seeds can be recovered. On the basis of genetic engineering technolo