Figure 3.

Acyl chain composition (in mol %) of total cell lipids (A) and of the FFAs released (B) in potato cells incubated under anoxia. Each data point is the average of two experiments (agreeing within ±1%). The acyl composition of total lipids in normoxic cells is essentially similar to that of anoxic cells and is therefore not detailed here. By definition, DBI = (Σ[N × mol % fatty acid ])/100, where Σ N is the number of double bonds in each fatty acid molecule. Here, DBI is thus equal to (0 × mol % 16:0 + 0 × mol % 18:0 + 1 × mol % 18:1 + 2 × mol % 18:2 + 3 × mol % 18:3)/100. In A, the DBI values were 1.788 at 0 h, 1.804 at 12 h, and 1.986 at 24 h. In B, the DBI values were 0.575 at 0 h, 0.734 at 12 h, and 1.912 at 24 h. The constancy of the fatty acid composition of total lipids in anoxia-treated cells (A) is in agreement with the requirement of acyl chain desaturation for O₂ (Harwood, 1988).