Genome-Wide Identification of the LAC Gene Family and Its Expression Analysis Under Stress in Brassica napus

Lignin is an important biological polymer in plants that is necessary for plant secondary cell wall ontogenesis. The laccase ( ) gene family catalyzes lignification and has been suggested to play a vital role in the plant kingdom. In this study, we identified 45 genes from the genome ( ), 25 genes from the genome ( ) and 8 genes from the genome ( ). These genes could be divided into five groups in a cladogram and members in same group had similar structures and conserved motifs. All contained hormone- and stress- related elements determined by cis-element analysis. The expression of was relatively higher in the root, seed coat and stem than in other tissues. Furthermore, and its predicted downstream genes showed earlier expression in the silique pericarps of short silique lines than long silique lines. Three miRNAs (miR397a, miR397b and miR6034) target 11 were also predicted. The expression changes of under series of stresses were further investigated by RNA sequencing (RNA-seq) and quantitative real-time polymerase chain reaction (qRT-PCR). The study will give a deeper understanding of the gene family evolution and functions in