Sullivan J A, Gray J C
Department of Plant Sciences and Cambridge Centre for Molecular Recognition, University of Cambridge, Downing Street, Cambridge, CB2 3EA, United Kingdom.
Plant Cell. 2000 Oct;12(10):1927-38. doi: 10.1105/tpc.12.10.1927.
The pea lip1 (light-independent photomorphogenesis1) mutant shows many of the characteristics of light-grown development when grown in continuous darkness. To investigate the identity of LIP1, cDNAs encoding the pea homolog of COP1, a repressor of photomorphogenesis identified in Arabidopsis, were isolated from wild-type and lip1 pea seedlings. lip1 seedlings contained a wild-type COP1 transcript as well as a larger COP1' transcript that contained an internal in-frame duplication of 894 bp. The COP1' transcript segregated with the lip1 phenotype in F(2) seedlings and could be translated in vitro to produce a protein of approximately 100 kD. The COP1 gene in lip1 peas contained a 7.5-kb duplication, consisting of exons 1 to 7 of the wild-type sequence, located 2.5 kb upstream of a region of genomic DNA identical to the wild-type COP1 DNA sequence. Transcription and splicing of the mutant COP1 gene was predicted to produce the COP1' transcript, whereas transcription from an internal promoter in the 2.5-kb region of DNA located between the duplicated regions of COP1 would produce the wild-type COP1 transcript. The presence of small quantities of wild-type COP1 transcripts may reduce the severity of the phenotype produced by the mutated COP1' protein. The genomic DNA sequences of the COP1 gene from wild-type and lip1 peas and the cDNA sequences of COP1 and COP1' transcripts have been submitted to the EMBL database under the EMBL accession numbers AJ276591, AJ276592, AJ289773, and AJ289774, respectively.
豌豆lip1（光不依赖型光形态建成1）突变体在持续黑暗中生长时表现出许多光下生长发育的特征。为了研究LIP1的身份，从野生型和lip1豌豆幼苗中分离出编码拟南芥中鉴定出的光形态建成抑制因子COP1的豌豆同源物的cDNA。lip1幼苗含有野生型COP1转录本以及一个更大的COP1'转录本，该转录本包含一个894 bp的内部读框内重复序列。COP1'转录本在F(2)幼苗中与lip1表型分离，并且可以在体外翻译产生一种约100 kD的蛋白质。lip1豌豆中的COP1基因包含一个7.5 kb的重复序列，由野生型序列的外显子1至7组成，位于与野生型COP1 DNA序列相同的基因组DNA区域上游2.5 kb处。预测突变的COP1基因的转录和剪接会产生COP1'转录本，而位于COP1重复区域之间的2.5 kb DNA区域内的内部启动子转录会产生野生型COP1转录本。少量野生型COP1转录本的存在可能会降低由突变的COP1'蛋白产生的表型的严重程度。野生型和lip1豌豆中COP1基因的基因组DNA序列以及COP1和COP1'转录本的cDNA序列已分别以EMBL登录号AJ276591、AJ276592、AJ289773和AJ289774提交到EMBL数据库。
