Molecular mechanism of genetic tumor induction by wound

遗传性肿瘤是由衰老或损伤诱导的，在体外无任何植物激素的条件下生长。由于灰绿烟草与兰氏烟草的杂种（F1）能有效地产生典型的肿瘤，因此我们将其作为本项目的实验材料。利用此材料，我们已经用差减法克隆了17个遗传肿瘤特异性cDNA（TID克隆）。其中一半与致病相关蛋白同源，其他克隆与任何已知基因均无同源性。与发根农杆菌同源的N.glauca中的Ngro1基因被发现在遗传肿瘤中特异性表达，在F1组织中，通过切割处理，在脱分化之后形成畸胎瘤，随后细胞继续分裂。与普通愈合不同的反应包括，例如，通常在植物中观察到的第二细胞壁增厚，包括F1植株的亲本植物。因此，我们分析了每个TID转录物对胁迫相关化学物质，如阿坝，茉莉酸甲酯和水杨酸的反应方式。我们还分析了植物激素，生长素和细胞分裂素的反应。结果表明，在F1代，胁迫相关化学物质诱导的转录产物也受到植物激素的诱导。发现Ngro1B受生长素诱导。另一方面，我们还获得了三个cDNA克隆，它们在遗传性肿瘤细胞中的转录被抑制。

Genetic tumors are induced by aging or injury and grow without any plant hormoes in vitro. Since hybrids between Nicotiana glauca and N.langsdorffii (F1) produced typical tumors efficiently, we used them as an experimental materials in this project. Using this material, we have already cloned 17 genetic tumor-specific cDNA (TID clones) by subtraction method. A half of them has a homology to the pathogenesis related proteins and other clones have no homology with any known genes. Ngro1 genes in N.glauca homologous to Agrobacterium rhizogenes have been found to express in genetic tumor specifically.In F1 tissues, by cutting treatments teratomas are formed after dedifferentiation that is followed by continuous cell division. The response which deiffers from the ordinary healing that includes, for example, second cell wall thickening usually observed in plants including the parent plants of F1 pkants, Therefore, we analyzed the way in which each TID transcript responed to stress-related chemicals, such as ABA,methyl-jasmonate and salicylic acid., We also analyzed the responses to plant hormones, an auxin and a cytokinin. The results showed, in general, in F1 tissues transcripts induced by stress-related chemicals were also induced by plant hormones. Ngro1B was found to be induced by auxins. On the other hand, we also obtained three cDNA clones, their transcription was suppressed in genetic tumor cells.