title: RNAi targeting putative genes in phosphatidylcholine turnover results in significant change in fatty acid composition in Crambe abyssinica seed oil.
abstract: The aim of this study was to evaluate the importance of three enzymes, LPCAT, PDCT and PDAT, involved in acyl turnover in phosphatidylcholine in order to explore the possibility of further increasing erucic acid (22:1) content in Crambe seed oil. The complete coding sequences of LPCAT1-1 and LPCAT1-2 encoding lysophosphatidylcholine acyltransferase (LPCAT), PDCT1 and PDCT2 encoding phosphatidylcholine:diacylglycerol cholinephosphotransferase (PDCT), and PDAT encoding phospholipid:diacylglycerol acyltransferase (PDAT) were cloned from developing Crambe seeds. The alignment of deduced amino acid sequences displayed a high similarity to the Arabidopsis homologs. Transgenic lines expressing RNA interference (RNAi) targeting either single or double genes showed significant changes in the fatty acid composition of seed oil. An increase in oleic acid (18:1) was observed, to varying degrees, in all of the transgenic lines, and a cumulative effect of increased 18:1 was shown in the LPCAT-PDCT double-gene RNAi. However, LPCAT single-gene RNAi led to a decrease in 22:1 accumulation, while PDCT or PDAT single-gene RNAi had no obvious effect on the level of 22:1. In agreement with the abovementioned oil phenotypes, the transcript levels of the target genes in these transgenic lines were generally reduced compared to wild-type levels. In this paper, we discuss the potential to further increase the 22:1 content in Crambe seed oil through downregulation of these genes in combination with fatty acid elongase and desaturases.
authors.affiliation: Department of Plant Breeding, Swedish University of Agricultural Sciences, PO Box 101, Alnarp, 230 53, Sweden.
authors.forename: Rui
authors.initials: R
authors.lastname: Guan
authors.forename: Xueyuan
authors.initials: X
authors.lastname: Li
authors.forename: Per
authors.initials: P
authors.lastname: Hofvander
authors.forename: Xue-Rong
authors.initials: XR
authors.lastname: Zhou
authors.forename: Danni
authors.initials: D
authors.lastname: Wang
authors.forename: Sten
authors.initials: S
authors.lastname: Stymne
authors.forename: Li-Hua
authors.initials: LH
authors.lastname: Zhu
mesh_terms: D008243:1-Acylglycerophosphocholine O-Acyltransferase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000217:Acyltransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D031218:Crambe Plant / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D004883:Erucic Acids / Q000032:analysis / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D010938:Plant Oils / Q000737:chemistry / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D034622:RNA Interference; D012639:Seeds / Q000737:chemistry / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017855:Transferases (Other Substituted Phosphate Groups) / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D004883:Erucic Acids; D010938:Plant Oils; C049811:erucic acid; D000217:Acyltransferases; C426836:phospholipid diacylglycerol acyltransferase; D008243:1-Acylglycerophosphocholine O-Acyltransferase; D017855:Transferases (Other Substituted Phosphate Groups)