Table 3. For the following five reactions no ESTs or genes were identified by our searches.

phosphatidylglycerol palmitate desaturase (FAD4),

monogalactosyldiacylglycerol palmitate desaturase (FAD5),

endoplasmic glycerol-3-phosphate acyltransferase,

plastidial and endoplasmic phosphatidylglycerol-3-phosphate phosphatase,

plastidial cytidine-5'-diphosphate-diacylglycerol synthase.

In the case of FAD4 and FAD5, the lack of identified clones is most likely because these genes cannot be distinguished from other desaturases in the database. However, our detailed examination of desaturase sequences has very likely identified strong candidate genomic and EST sequences for the FAD5 desaturase.