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Physaria fendleri and Ricinus communis lecithin:cholesterol acyltransferase‐like phospholipases selectively cleave hydroxy acyl chains from phosphatidylcholine
- Source :
- The Plant Journal. 105:182-196
- Publication Year :
- 2020
- Publisher :
- Wiley, 2020.
-
Abstract
- Production of hydroxy fatty acids (HFAs) in transgenic crops represents a promising strategy to meet our demands for specialized plant oils with industrial applications. The expression of Ricinus communis (castor) OLEATE 12-HYDROXYLASE (RcFAH12) in Arabidopsis has resulted in only limited accumulation of HFAs in seeds, which probably results from inefficient transfer of HFAs from their site of synthesis (phosphatidylcholine; PC) to triacylglycerol (TAG), especially at the sn-1/3 positions of TAG. Phospholipase As (PLAs) may be directly involved in the liberation of HFAs from PC, but the functions of their over-expression in HFA accumulation and distribution at TAG in transgenic plants have not been well studied. In this work, the functions of lecithin:cholesterol acyltransferase-like PLAs (LCAT-PLAs) in HFA biosynthesis were characterized. The LCAT-PLAs were shown to exhibit homology to LCAT and mammalian lysosomal PLA2 , and to contain a conserved and functional Ser/His/Asp catalytic triad. In vitro assays revealed that LCAT-PLAs from the HFA-accumulating plant species Physaria fendleri (PfLCAT-PLA) and castor (RcLCAT-PLA) could cleave acyl chains at both the sn-1 and sn-2 positions of PC, and displayed substrate selectivity towards sn-2-ricinoleoyl-PC over sn-2-oleoyl-PC. Furthermore, co-expression of RcFAH12 with PfLCAT-PLA or RcLCAT-PLA, but not Arabidopsis AtLCAT-PLA, resulted in increased occupation of HFA at the sn-1/3 positions of TAG as well as small but insignificant increases in HFA levels in Arabidopsis seeds compared with RcFAH12 expression alone. Therefore, PfLCAT-PLA and RcLCAT-PLA may contribute to HFA turnover on PC, and represent potential candidates for engineering the production of unusual fatty acids in crops.
- Subjects :
- 0106 biological sciences
0301 basic medicine
food.ingredient
Arabidopsis
Plant Science
Phospholipase
Plant Roots
01 natural sciences
Lecithin
Substrate Specificity
Phosphatidylcholine-Sterol O-Acyltransferase
03 medical and health sciences
chemistry.chemical_compound
food
Biosynthesis
Phosphatidylcholine
Catalytic triad
Genetics
Plant Proteins
biology
Ricinus
Fatty Acids
Cell Biology
Plants, Genetically Modified
biology.organism_classification
Physaria fendleri
Protein Structure, Tertiary
030104 developmental biology
chemistry
Biochemistry
Brassicaceae
Seeds
Phosphatidylcholines
lipids (amino acids, peptides, and proteins)
Lysophospholipids
010606 plant biology & botany
Subjects
Details
- ISSN :
- 1365313X and 09607412
- Volume :
- 105
- Database :
- OpenAIRE
- Journal :
- The Plant Journal
- Accession number :
- edsair.doi.dedup.....8ac96a395ffab2fce9686004b571bf26