乙酰辅酶A羧化酶是一个生物素羧化酶，它所催化的反应是脂肪酸生物合成中的第一个关键步骤。禾本科植物叶绿体中的乙酰辅酶A羧化酶是两类禾本科除草剂的靶蛋白。从抗除草剂拿捕净和感拿捕净的谷子(Setaria italica Beauv．)中克隆了两个乙酰辅酶A羧化酶的全长cDNA，分别命名为foxACC-R和foxACC-S，它们推导的蛋白质均编码2321个氨基酸，然而在第l 780个氨基酸处，foxACC-R编码亮氨酸，而foxACC-S编码异亮氨酸。采用生物信息学方法，我们推断这个cDNA编码的是叶绿体中的乙酰辅酶A羧化酶，并预测了它的功能域和保守区。通过这两个cDNA编码的氨基酸序列与其他乙酰辅酶A羧化酶的序列比较得出结论，亮氨酸／异亮氨酸位点可能是．APPs和cHDs两类除草剂作用的关键位点。Southern杂交分析的结果显示，该基因在谷子基因组中只有一个拷贝。
To investigate the expression profile of maize genes induced by submergence, a subtracted cDNA library of maize seedling roots was constructed using suppression subtractive hybridization (SSH). The cDNA of maize seedling roots treated with submergence (ST) was used as tester and what from untreated roots (UT) as driver. Products of the secondary PCR from the forward subtraction were cloned into T/A vector and transferred into Escherichia coli strain JM10B by electroporation. Four hundred and eight randomly chosen transformants carrying cDNA fragments were screened with PCR-Select Deferential Screening Kit. One hundred and eighty-four cDNA clones were identified as, submergence specifically induced or highly expressed. After sequencing and removing redundant cDNAs, we got 95 submergence-induced cDNA clones. Of the 95 cDNA clones, 68 contain the regions with 60%-90% identity to their homolog in GenBank, 21 are expected to be novel genes, only 6 correspond to the published maize sequences.
