MOLECULAR BIOLOGICAL STUDY ON THE MECHANISM OF LIGHTINDUCED DWARFISM (LIGHT-INDUCED GENE EXPRESSION IN DWARF PEA PLANTS)

为了阐明光诱导豌豆矮化的机理，利用差异显示技术对豌豆矮化相关基因进行了研究。Poly（A）^+ RNA是从光生矮豌豆（Pisum sativum L.cv. Progress No 9）和正常豌豆（cv.阿拉斯加）的幼苗和两个品种的旱生幼苗。逆转录Poly（A）^+ RNA后，用72种随机引物进行差异显示，鉴定特异性基因。鉴定了差异表达的20条条带，并选择其中7条进行进一步表征。将这7条带克隆到质粒载体中，测定其核苷酸序列，并在GenBank中搜索其同源物。使用克隆的编码序列作为探针，通过高严格性的北方印迹进一步表征克隆。结果表明，其中一个克隆在光生矮生豌豆幼苗中特异表达，另一个克隆在除光生矮生豌豆幼苗外的所有幼苗中特异表达。因此，这两个克隆，这是新的基因，可能参与了光诱导的矮生豌豆植株的矮化。

In order to clarify the mechanism of light-induced dwarf ism, a search for specific gene involved the dwarfism in dwarf pea plants was undertaken using differential display method. Poly(A)^+ RNA was isolated from light-grown dwarf pea (Pisum sativum L.cv. Progress No 9) and normal pea (cv. Alaska) seedlings and dank-grown seedlings of both cultivars. After reverse transcription of the Poly(A) ^+ RNA, the differential display method was employed to identify specific genes using 72 kinds of random primers. Differentially expressed 20 bands were identified and seven of them were chosen for further characterization. These seven bands were cloned into plasmid vectors and their nucleotide sequences were determined and searched for their homologues in GenBank. Using the cloned coding sequence as probes, the clones were characterized further by Northern blotting at high stringency. The result shown that one clone was specifically expressed in the light-grown dwarf pea seedlings and one was expressed in all seedlings expect the light-grown dwarf pea seedlings. Thus, the two clones, which are novel genes, may be involved in the light-induced dwarfism of the dwarf pea plants.