Department of Molecular Biology and Plant Pathology, University of Wisconsin, 53706, Madison, WI, USA.
Plant Mol Biol. 1985 Jul;4(4):253-63. doi: 10.1007/BF02418244.
Site-specific insertion and deletion mutations affecting all six of the eukaryotic-like genes in the TR-DNA region of the octopine-type Ti plasmids pTil5955 or pTiA6 have been generated. None of the mutations affected virulence or tumor morphology on sunflower. Mutations in the coding regions of two of the genes resulted in tumors without any detectable mannopine, mannopinic acid or agropine, and mutations in either the coding region or in the 3' untranslated region of a third gene eliminated biosynthesis of agropine, but not mannopine or mannopinic acid. Detection of two previously unobserved silver nitrate-positive substance in tumors incited by one of the mutant strains, together with data on the presence of opines in tumors incited by coinoculation with mixtures of different mutant strains, allowed us to propose the functional order of all three genes involved in the biosynthesis of mannopine, mannopinic acid and agropine. TR-DNA was absent in tumors incited by anAgrobacterium tumefaciens strain harboring a Ti plasmid in which the right border of the TR-DNA region was deleted.
已经产生了影响八氢番茄红素合酶基因的所有六个真核样基因在 octopine 型 Ti 质粒 pTil5955 或 pTiA6 的 TR-DNA 区的位点特异性插入和缺失突变。这些突变都没有影响在向日葵上的毒性或肿瘤形态。两个基因的编码区的突变导致没有任何可检测的吗啉、吗啉酸或农杆碱的肿瘤，而第三个基因的编码区或 3'非翻译区的突变消除了农杆碱的生物合成，但不影响吗啉或吗啉酸。在一种突变株诱导的肿瘤中检测到两种以前未观察到的硝酸银阳性物质，以及在不同突变株混合物共接种诱导的肿瘤中存在生物碱的存在的数据，使我们能够提出涉及吗啉、吗啉酸和农杆碱生物合成的三个基因的功能顺序。在携带 Ti 质粒的根癌农杆菌菌株中，TR-DNA 缺失了 TR-DNA 区的右边界，在由其诱导的肿瘤中不存在 TR-DNA。
