Transformation Of Brassica Napus With Arabidopsis Phospholipase D

Rapeseed (Brassica napus) is a major crop plant in the middle area of China. It is important to improve rapeseed quality via genetics method. Phospholipase D (PLD) hydrolyzes phospholipids to produce phosphatidic acid (PA) and a free head group, resulting in membrane remodeling, cytoskeletonal reorganization, and activity changes of target proteins associated membranes. PLD is detectable in various tissues in plants and was studied extensively recently. Increasing evidence shows that PA generated by phospholipids hydrolyzed by PLD is an important signaling molecule involved in various biological processes including plant growth, development and stress response. This study was undertaken to overexpress AtPLDβ1 and AtPLDy3 in rapeseed via agrobacterium meiated transformation.The main results of this study were as follows:1.In this study, the expression level of Phospholipase Dβ1 was analyzed in 75 lines of transgenic plants. As a result,32 percent of plants was overexpressed in brassica plants. In case of phospholipase D y3(AtPLDy3-OE), fourteen (22.6%) lines are overexpressed in 62 lines of plants tested. Due to the limitation of growth condition, I collected seeds from 24 lines of plants, which included fourteen lines of AtPLDβ1-OE plants and ten lines of AtPLDy3-OE plants. Among fourteen 24 lines of transgenic plants, PLDβ1 protein level in ten lines were higher than wild type (WT) control, and mRNA level in four lines were higher than that of WT.2. To investigate the physiological effects of PLDβ1 and PLDy3 on brassica plants, I also measured root length and shoot length during 3-leaf-old stage under nitrogen limitation and salt stress. There is not significant different between transformed and wild type plants at this moment. In some transgenic plants, the growth of both lateral root and primary root were inhibited when seeds were germinated in pure water. And polycotyledon and cotyledon deficiency were also found in some lines.