Guo W, Ward R W, Thomashow M F
Department of Crop and Soil Sciences, Michigan State University, East Lansing, Michigan 48824-1325.
Plant Physiol. 1992 Oct;100(2):915-22. doi: 10.1104/pp.100.2.915.
The cDNA clone pWG1 represents a gene, designated cor39, from Triticum aestivum L. cv Winoka (a winter wheat) that is related to a cold-regulated Arabidopsis thaliana L. (Heyn) gene, cor47. In vitro transcription/translation experiments in conjunction with DNA sequence analysis indicated that cor39 encodes a hydrophilic polypeptide of 39 kD (isoelectric point of 7.5), designated COR39. The polypeptide is composed primarily of two sequences, each of which is repeated six times. One sequence, which is lysine rich, occurs in COR47 (the polypeptide encoded by Arabidopsis cor47) and group II LEA proteins, polypeptides hypothesized to have roles in desiccation and drought tolerance (J. Baker, C. Steele, L. Dure III [1988] Plant Mol Biol 11: 277-291). The second sequence, which is glycine rich, occurs in some, but not all, group II LEA proteins. Southern analysis indicated that wheat has a number of loci related to cor39. Transcripts of about 3.3, 1.5, and 0.8 kb that hybridize with cor39 were found to accumulate in leaf, root, and crown tissues of cold-acclimated plants; they accumulated rapidly in response to low temperature and returned quickly to low levels when plants were returned to normal growth temperature. Transcripts hybridizing with cor39 were present at relatively high levels in wheat seeds and accumulated in plants in response to exogenous application of ABA and water stress. The similarities in expression of wheat and Arabidopsis cor genes and possible functional relationships among COR39, COR47, and LEA proteins are discussed.
cDNA克隆pWG1代表一个来自普通小麦品种Winoka（冬小麦）的基因，命名为cor39，它与拟南芥中一个受低温调控的基因cor47相关。体外转录/翻译实验结合DNA序列分析表明，cor39编码一个39 kD的亲水性多肽（等电点为7.5），命名为COR39。该多肽主要由两个序列组成，每个序列重复六次。其中一个富含赖氨酸的序列存在于COR47（拟南芥cor47编码的多肽）和第II组LEA蛋白中，这些多肽被认为在脱水和耐旱方面发挥作用（J. Baker、C. Steele、L. Dure III [1988] Plant Mol Biol 11: 277 - 291）。第二个富含甘氨酸的序列存在于部分但不是所有的第II组LEA蛋白中。Southern分析表明小麦有许多与cor39相关的基因座。发现与cor39杂交的约3.3、1.5和0.8 kb的转录本在低温驯化植物的叶片、根和冠组织中积累；它们在低温响应下迅速积累，当植物恢复到正常生长温度时又迅速恢复到低水平。与cor39杂交的转录本在小麦种子中相对高水平存在，并在植物对外源施加脱落酸和水分胁迫时积累。本文讨论了小麦和拟南芥cor基因表达的相似性以及COR39、COR47和LEA蛋白之间可能的功能关系。
