Cloning and Expression Level Analysis of Two BnaANT Candidate Genes in Brassica napus

AINTEGUMENTA (ANT) gene has been proved to have a novel function on controlling the organ size and the seed weight in Arabidopsis thaliana, the research on its orthologous gene in Brassica napus will be of potential interest to elucidate the molecular mechanism of rapeseed development and increase the rapeseed output. A SMART cDNA library of the flower bud from B. napus cultivar Zhongshuang 9 was constructed, and the full-length cDNAs of two homologous BnaANT candidate genes were cloned by PCR in B. napus, namely BnaX.ANT.a (GenBank accession no. DQ211969) and BnaX.ANT.b (accession no. DQ211970). They shared 87.1 and 83.4% amino acid identity with ANT of A. thaliana, respectively. There is 87.4% amino acid identity between BnaX.ANT.a and BnaX.ANT.b. By quantitative real-time PCR, the obviously differential expression levels of the two BnaANT candidate genes were detected in the 28 DAF seeds of the big and small grains B. napus lines, the expression abundance of BnaANT in the 28 DAF seed of 9311 was over three times compared to that of 9260, which indicates that these two BnaANT genes are also likely related to the floral organ size and the seed weight in B. napus.