Table II.

Substrate specificity of the plastidial desaturases BnFAD6 and PtFAD6 expressed in Synechococcus

Substrate	Product(s)	Desaturation
		BnFAD6	PtFAD6
		%
16:1Δ7	16:2Δ7,10	79.6 ± 5.8	5.2 ± 0.8
16:1Δ9	16:2Δ9,12, 18:2Δ11,14a	15.5 ± 1.9	70.3 ± 3.1
18:1Δ9	18:2Δ9,12	87.3 ± 4.9	20.6 ± 2.5
20:1Δ11	20:2Δ11,14	19.4 ± 2.2	0
22:1Δ13	22:2Δ13,15	0	0

Synechococcus was transformed with pFP1-BnFAD6 or pFP1-PtFAD6 and grown for 7 d at 23°C in the presence of different fatty acid substrates (75 μm) in separate experiments. FAMEs from the whole cells were prepared and analyzed by GLC as indicated in “Materials and Methods.” Desaturation (percentage) was calculated as (product(s) × 100)/(educt + product(s)) using values corresponding to percent of total fatty acids. Each value is the mean ± sd from three to five independent experiments.

^a Due to the endogenous elongation of the desaturase product 16:2^Δ9,12.