Liu J H, Hill R D
Department of Plant Science, University of Manitoba, Winnipeg, Canada.
Plant Mol Biol. 1995 Dec;29(5):1087-91. doi: 10.1007/BF00014980.
Changes in bifunctional alpha-amylase/subtilisin inhibitor (BASI) expression induced by abscisic acid (ABA) were studied using in vitro cultured barley (Hordeum vulgare cv. Bonanza) embryos. The steady-state levels of BASI mRNA and BASI protein were increased by exogenously applied ABA. Accumulation of BASI protein was preceded by an increase in message level. The results suggest that ABA does not affect BASI mRNA translation. Nuclear run-on assays demonstrated that ABA had no effect on transcriptional activity. BASI mRNA was not detectable in the embryos treated with a protein synthesis inhibitor, cycloheximide, which had no inhibitory effect on BASI transcription rate. We propose that ABA increases the stability of BASI mRNA through synthesis of a short-lived protein that protects the message.
利用体外培养的大麦（Hordeum vulgare cv. Bonanza）胚，研究了脱落酸（ABA）诱导的双功能α-淀粉酶/枯草杆菌蛋白酶抑制剂（BASI）表达的变化。外源施加的ABA提高了BASI mRNA和BASI蛋白的稳态水平。BASI蛋白的积累先于信息水平的增加。结果表明，ABA不影响BASI mRNA的翻译。核转录分析表明，ABA对转录活性没有影响。在用蛋白质合成抑制剂环己酰亚胺处理的胚中未检测到BASI mRNA，环己酰亚胺对BASI转录速率没有抑制作用。我们提出，ABA通过合成一种保护信息的短命蛋白来提高BASI mRNA的稳定性。
