title: Seed structure characteristics to form ultrahigh oil content in rapeseed.
abstract: BACKGROUND
  Rapeseed (Brassica napus L.) is an important oil crop in the world, and increasing its oil content is a major breeding goal. The studies on seed structure and characteristics of different oil content rapeseed could help us to understand the biological mechanism of lipid accumulation, and be helpful for rapeseed breeding.
  
  
  RESULTS
  Here we report on the seed ultrastructure of an ultrahigh oil content rapeseed line YN171, whose oil content is 64.8%, and compared with other high and low oil content rapeseed lines. The results indicated that the cytoplasms of cotyledon, radicle, and aleuronic cells were completely filled with oil and protein bodies, and YN171 had a high oil body organelle to cell area ratio for all cell types. In the cotyledon cells, oil body organelles comprised 81% of the total cell area in YN171, but only 53 to 58% in three high oil content lines and 33 to 38% in three low oil content lines. The high oil body organelle to cotyledon cell area ratio and the cotyledon ratio in seed were the main reasons for the ultrahigh oil content of YN171. The correlation analysis indicated that oil content is significantly negatively correlated with protein content, but is not correlated with fatty acid composition.
  
  
  CONCLUSIONS
  Our results indicate that the oil content of YN171 could be enhanced by increasing the oil body organelle to cell ratio for some cell types. The oil body organelle to seed ratio significantly highly positively correlates with oil content, and could be used to predict seed oil content. Based on the structural analysis of different oil content rapeseed lines, we estimate the maximum of rapeseed oil content could reach 75%. Our results will help us to screen and identify high oil content lines in rapeseed breeding.
authors: Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, Hubei, People's Republic of China.
authors: Zhi-Yong
authors: ZY
authors: Hu
authors: Wei
authors: W
authors: Hua
authors: Liang
authors: L
authors: Zhang
authors: Lin-Bin
authors: LB
authors: Deng
authors: Xin-Fa
authors: XF
authors: Wang
authors: Gui-Hua
authors: GH
authors: Liu
authors: Wan-Jun
authors: WJ
authors: Hao
authors: Han-Zhong
authors: HZ
authors: Wang
mesh_terms: D029741:Brassica rapa / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure*; D001947:Breeding; D005227:Fatty Acids / Q000032:analysis; D005229:Fatty Acids, Monounsaturated; D015388:Organelles / Q000378:metabolism; D010938:Plant Oils / Q000737:chemistry / Q000378:metabolism*; D000074262:Rapeseed Oil; D012639:Seeds / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure*
chemical_list: D005227:Fatty Acids; D005229:Fatty Acids, Monounsaturated; D010938:Plant Oils; D000074262:Rapeseed Oil
references: Biochem J. 1983 Apr 15;212(1):223-9
references: 6135419
references: Theor Appl Genet. 2012 Aug;125(4):715-29
references: 22534790
references: Plant Cell Rep. 2009 Apr;28(4):541-9
references: 19093121
references: Plant J. 1997 Apr;11(4):783-96
references: 9161036
references: Proteomics. 2006 Aug;6(16):4586-98
references: 16847873
references: Plant Physiol. 1993 Jan;101(1):267-276
references: 12231682
references: Science. 1995 May 5;268(5211):681-6
references: 17832379
references: Theor Appl Genet. 2006 Dec;114(1):67-80
references: 17033785
references: Plant Cell. 2006 Aug;18(8):1961-74
references: 16877495
references: Ann Bot. 2000 Jun;85(6):851-9
references: 11543312
references: Ann Bot. 2006 Jun;97(6):999-1010
references: 16675608