Transformation of soft rot resistant aiiA gene into Chinese cabbage (Brassica rapa ssp. pekinensis) by the pollen-tube pathway

Abstract

Bacterial soft rot of Chinese cabbage is the most destructive disease caused by Erwinia carotovora. Until now reliable sources of resistance and effective control methods are unavailable, so development of highly resistant breeding lines is desirable. In the present study, we established an aiiA gene transformation system of soft rot resistant. The aiiA gene was introduced into Chinese cabbage through the pollen-tube pathway using the plasmid vector pBBBast-aiiA (7, 315 kb), which included aiiA gene, expression regulatory sequence (CaMV 35S promoter, OCS terminator), the herbicide resistant Bar gene and other elements. Five out of 20632 (0.02%) of T0 plants was positive for aiiA gene through PCR. Further PCR Southern blot analysis displayed that the gene aiiA segments were transformed into T0 plants. These transgenic plants could be the potential cultigens against the pathogens of soft rot for Chinese cabbage.