Joh T, Honjoh K, Yoshimoto M, Funabashi J, Miyamoto T, Hatano S
Department of Food Science and Technology, Faculty of Agriculture, Kyushu University, Fukuoka, Japan.
Plant Cell Physiol. 1995 Jan;36(1):85-93.
To investigate the effects of hardening on gene expression in Chlorella vulgaris Beijerink IAM C-27 (formerly Chlorella ellipsoidea Gerneck IAM C-27), a frost-hardy strain, 17 cDNA clones corresponding to hardening-induced Chlorella (hiC) genes were isolated by differential screening of a cDNA library from 6-h hardened cells. Northern blot analysis of transcripts of hiC genes showed that these genes are specifically induced by hardening and that their patterns of induction vary. Southern blots of genomic DNAs from two strains (Chlorella ellipsoidea Gerneck IAM C-102, chilling-sensitive; and C. vulgaris C-27, frost-hardy) of Chlorella indicated that ten hiC clones out of 17 hybridized only with DNA of strain C-27 and the other seven clones hybridized with DNA of both strains. However, of these seven clones, transcripts corresponding to six clones did not accumulate in strain C-102 at low temperatures. The sequence of a deduced protein encoded by the most abundant clone, hiC6, exhibited homology to sequences of Group III LEA (late embryogenesis abundant) proteins and had an amino-terminal amino acid sequence that was similar to the sequences of chloroplast transit peptides.
为了研究硬化处理对耐寒小球藻(Chlorella vulgaris Beijerink IAM C-27,原椭圆小球藻Chlorella ellipsoidea Gerneck IAM C-27)基因表达的影响,通过对经6小时硬化处理的细胞构建的cDNA文库进行差异筛选,分离出了17个与硬化诱导的小球藻(hiC)基因相对应的cDNA克隆。对hiC基因转录本的Northern印迹分析表明,这些基因是由硬化处理特异性诱导的,且它们的诱导模式各不相同。对小球藻的两个菌株(椭圆小球藻Gerneck IAM C-102,冷敏感型;普通小球藻C-27,耐寒型)的基因组DNA进行Southern印迹分析表明,17个hiC克隆中有10个仅与C-27菌株的DNA杂交,另外7个克隆与两个菌株的DNA都杂交。然而,在这7个克隆中,对应于6个克隆的转录本在低温下在C-102菌株中不积累。最丰富的克隆hiC6编码的推导蛋白序列与III组LEA(胚胎后期丰富)蛋白的序列具有同源性,并且其氨基末端氨基酸序列与叶绿体转运肽的序列相似。