Differential expression of duplicated peroxidase genes in the allotetraploid Brassica napus.
Gene redundancy due to polyploidization provides a selective advantage for plant adaptation. We examined the expression patterns of two peroxidase genes (BnPOX1 and BnPOX2) in the natural allotetraploid Brassica napus and the model diploid progenitors Brassica rapa (Br) and Brassica oleracea (Bo) in response to the fungal pathogen Sclerotinia sclerotiorum. We demonstrated that the Bo homeolog of BnPOX1 was up-regulated after infection, while both BnPOX2 homeologs were down-regulated. A bias toward reciprocal expression of the homeologs of BnPOX1 in different organs in the natural allotetraploid of B. napus was also observed. These results suggest that subfunctionalization of the duplicated BnPOX genes after B. napus polyploidization as well as subneofunctionalization of the homeologs in response to this specific biotic stress has occurred. Retention of expression patterns in the diploid progenitors and the natural allotetraploid in some organs indicates that the function of peroxidase genes has been conserved during evolution.
Zhao
Jianwei
J
Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK, Canada S7N 0X2; College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Buchwaldt
Lone
L
Rimmer
S Roger
SR
Brkic
Myrtle
M
Bekkaoui
Diana
D
Hegedus
Dwayne
D
D001203:Ascomycota; D029688:Brassica napus / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D020131:Genes, Duplicate; D017343:Genes, Plant; D005810:Multigene Family; D009195:Peroxidase / Q000235:genetics* / Q000378:metabolism; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology*; D018514:Plant Structures; D011123:Polyploidy
D009195:Peroxidase