Takahashi Y, Kuroda H, Tanaka T, Machida Y, Takebe I, Nagata T
Department of Biology, Faculty of Science, Nagoya University, Japan.
Proc Natl Acad Sci U S A. 1989 Dec;86(23):9279-83. doi: 10.1073/pnas.86.23.9279.
A cDNA clone for an auxin-regulated gene was isolated from a tobacco mesophyll protoplast cDNA library by differential screening. Nucleotide, sequence analysis showed that the deduced product of the gene, which we have designated par, is hydrophilic and is composed of 220 amino acids. No significant homology to other known proteins was detected. The mRNA of the par gene is approximately 900 bases long and its accumulation was detected in cultured mesophyll protoplasts as early as 30 min after the addition of 2,4-dichlorophenoxyacetic acid to the culture medium. The par mRNA was not detected in leaves or freshly prepared protoplasts or in protoplasts in the absence of 2,4-dichlorophenoxyacetic acid. Expression of the par gene was detected at a low level in actively dividing BY-2 tobacco suspension culture cells. The conspicuous accumulation of par mRNA before the initiation of DNA synthesis in tobacco mesophyll protoplasts suggests that the par gene product could play a role in the initiation of meristematic activity in differentiated mesophyll cells.
通过差异筛选，从烟草叶肉原生质体cDNA文库中分离出一个生长素调节基因的cDNA克隆。核苷酸序列分析表明，该基因（我们命名为par）推导的产物具有亲水性，由220个氨基酸组成。未检测到与其他已知蛋白质有显著同源性。par基因的mRNA约900个碱基长，早在向培养基中添加2,4-二氯苯氧乙酸后30分钟，就在培养的叶肉原生质体中检测到其积累。在叶片、新鲜制备的原生质体或无2,4-二氯苯氧乙酸的原生质体中未检测到par mRNA。在活跃分裂的BY-2烟草悬浮培养细胞中检测到par基因的低水平表达。烟草叶肉原生质体中DNA合成开始前par mRNA的显著积累表明，par基因产物可能在分化的叶肉细胞分生组织活性的启动中起作用。
