Enzyme activities in total protein extracts from PHB producing transgenic sugarcane and switchgrass. A-B PhaA (dark bars) and PhaB (light bars) activity in whole leaf protein extracts of sugarcane (A) and switchgrass (B). (C, D) PhaA activity in sugarcane (C) and switchgrass (D) M (white bars) and BS (black bars) chloroplast protein fractions. (E) PhaB activity in switchgrass M and BS chloroplast protein fractions. LP, low PHB producer (≤1% DW); MP, medium producer (>1% ≤ 2% DW); HP, high producer (>2% DW). Error bars represent standard error (n = 3).