Yoon I S, Mori H, Kim J H, Kang B G, Imaseki H
Department of Biology, Yonsei University, Seoul, Republic of Korea.
Plant Cell Physiol. 1997 Mar;38(3):217-24. doi: 10.1093/oxfordjournals.pcp.a029156.
We have isolated four cDNA clones of ACC synthase from etiolated mungbean seedlings treated with auxin. pVR-ACS2, pVR-ACS3 and pVR-ACS6 contained the same sequences as the previously reported DNA fragments, pMAC2, pMAC3 (Botella et al. 1992b) and pMBA1 (Kim et al. 1992), respectively. pVR-ACS1 was identical with pAIM-1 (Botella et al. 1992a). VR-ACS6 was specifically induced in response to the auxin signal. The IAA-induction of VR-ACS6 was very rapid (within 30 min) and insensitive to cycloheximide treatment at concentrations up to 100 microM. Significant accumulation of VR-ACS6 mRNA was detected at 1 microM IAA. The IAA-induced expression of VR-ACS6 was suppressed by ABA and ethylene, but enhanced by BA. These characteristics of VR-ACS6 expression were well correlated with the physiological data of auxin-induced ethylene production in mungbean hypocotyls. VR-ACS1 was strongly induced by cycloheximide, but was found to be not auxin-specific. Inhibitors of either ethylene biosynthesis (AOA) or action (NBD) increased the basal level of VR-ACS1 mRNA.
我们从用生长素处理的黄化绿豆幼苗中分离出了四个ACC合酶的cDNA克隆。pVR-ACS2、pVR-ACS3和pVR-ACS6分别包含与先前报道的DNA片段pMAC2、pMAC3（Botella等人，1992b）和pMBA1（Kim等人，1992）相同的序列。pVR-ACS1与pAIM-1（Botella等人，1992a）相同。VR-ACS6是对生长素信号特异性诱导的。VR-ACS6的IAA诱导非常迅速（在30分钟内），并且对浓度高达100 microM的放线菌酮处理不敏感。在1 microM IAA时检测到VR-ACS6 mRNA的显著积累。ABA和乙烯抑制IAA诱导的VR-ACS6表达，但BA增强该表达。VR-ACS6表达的这些特征与绿豆下胚轴中生长素诱导的乙烯产生的生理数据密切相关。VR-ACS1被放线菌酮强烈诱导，但发现不是生长素特异性的。乙烯生物合成抑制剂（AOA）或作用抑制剂（NBD）增加了VR-ACS1 mRNA的基础水平。
