Stymne, Sten
- Institutionen för växtvetenskap, Sveriges lantbruksuniversitet
Sammanfattning
A gene with homologies to animal phospholipid:sterol acyltransferase (LCAT or SAT) and to the plant and the yeast phospholipid:diacylglycerol acyltransferase (PDAT) was identified in the available Arabidopsis gene data bases. The cDNA for this gene was overexpressed in Arabidopis behind the 35S CaMV promotor. Three different T3 homozygous lines expressing the gene at different levels were chosen for assays of enzymatic activity. Microsomal preparations from leaves and roots of the transformants had SAT activity that correlated to expression levels of the gene whereas SAT activity was barely detected in the control plants. The enzyme was further characterised in the highest overexpresser. The enzyme utilised phosphatidylcethanolamine (PE) at about five times higher rate than phosphatidylcholine and transferred acyl groups from the sn-2 position. Highest activity was seen with polyunsaturated acyl groups whereas saturated and monounsaturated were utilized at equal rates. When acyl acceptor specificity of the enzyme was measured as an increase in radioactive sterol ester production from [14C]18:1-PE, 11 out of 14 different sterols added to the enzyme assays gave increased radioactive sterol ester synthesis. The effects on sterol and sterol ester content and composition in the plant in the SAT overexpressers and in SAT T-DNA insertion mutants is given in another presentation (Noiriel et al.)
Konferens
16th International Plant Lipid Symposium
SLU författare
Carlsson, Anders
- Institutionen för växtvetenskap, Sveriges lantbruksuniversitet
- Institutionen för växtvetenskap, Sveriges lantbruksuniversitet
UKÄ forskningsämne
Jordbruksvetenskap
Permanent länk till denna sida (URI)
https://res.slu.se/id/publ/5383