甘蓝型油菜ACCase、 DGAT2和PEPC基因对氮素用量的应答

氮肥是生长发育需要的重要营养元素之一。为了研究氮肥对油菜蛋白与油脂含量以及其合成相关基因表达水平的影响，本研究以品种中双11和Parter（德国）为材料，检测N 0、 90、 180和270 kg/hm2氮肥水平下种子含油量和蛋白质含量，并检测ACCase，DGAT2和PEPC基因在施氮肥（N 180 kg/hm2）和未施氮肥植株不同发育时期种子中的表达水平。结果发现，随施氮量增加，含油量降低，蛋白质含量增加，且Parter含油量下降程度明显高于中双11。授粉后725 d， ACCase和DGAT2的表达水平在两个品种施氮和未施氮条件下均无明显变化; 授粉后31d，施氮与未施氮相比，两个基因在中双11中的表达量分别下降1倍和12倍，而在Parter中的表达量均上升约1倍。在施氮条件下，PEPC基因在两个品种的表达高峰期均提前，中双11由授粉后31 d提前到13 d，Parter由13 d提前到7 d，说明3个基因对氮肥的响应存在基因型的差异。

Response of ACCase, DGAT2 and PEPC genes in developing seeds of Brassica napus L. to different nitrogen levels

 Nitrogen fertilizer is one of the major nutrition to Brassica napus L. To assess the influence of nitrogen fertilizer on protein and oil contents of B. napus and expression of their synthesis related genes, A field experiment was carried out under four nitrogen fertilizer gradients, 0, 90, 180 and 270 kg/ha, using B. napus cultivars Zhongshuang 11 and Parter (from Germany). The oil content and protein abundance in matured seeds were investigated. Gene expression profiles of ACCase, DGAT2 and PEPC of seeds at different development stages between nitrogen fertilizer treated (180 kg/ha) and blank control of the two cultivars were set up. The results indicate that the seeds protein abundances are increased and the oil contents are decreased under the higher nitrogen fertilizer levels, and the oil content of Parter is more obviously decreased compared to Zhongshuang 11 Compared the gene expression levels between the treatment and the control, the expression levels of ACCase and DGAT2 have no obvious differences for the two cultivars during 7-25 days after the pollination (DAPs). However, at the 31 DAP, the two genes in Zhongshuang 11 are down regulated 1 and 12 folds respectively, while the two genes in Parter are up  regulated 1 fold. The expression peaks of PEPC are all brought forward in the treatments of the two peaks of PEPC are changed from 31 DAP to 13 DAP in Zhongshuang 11 and changed from 13 DAP to 7 DAP in Parter. The results indicate that there are genotype differences in the three genes responding to the nitrogen fertilizer.