IDENTIFICATION OF IAA GENES AND ITS REGULATION IN TAPHRINA WIESNERI

与植物细菌病原菌（Pseudomonassavastanoi）和根癌农杆菌（Agrobacteriumtumefaciens）一样，植物真菌增生病原菌（Taphrinawiesneri、Taphrindeformans和Taphrinpruni）也能产生高浓度的IAA和细胞分裂素，从而破坏宿主细胞内激素平衡，导致植物细胞增生。并对该途径的相关酶进行了纯化，以探讨IAA生物合成的调控机制。进一步获得了IAA-突变体，并对突变体进行了脉冲场凝胶电泳分析. <Biostnthetic pathway of IAA and their regulation>魏氏塔氏霉（Taphrina wiesneri）中IAA的生物合成途径有两条：1）从L-色氨酸（Trp）、吲哚-3-丙酮酸（IPA）、吲哚-3-乙醛（IAAL）合成IAA; 2）从吲哚-3-乙腈（IAN）合成IAA。虽然色氨酸氨基转移酶（TATase 关于我们 ）将Trp转化为IPA的酶是不可诱导的，将IAN转化为IAA的IAN腈水解酶是可诱导的。其中一条IAA生物合成途径是通过IAA 1的氧化或还原来调节的，这是因为在魏氏锥虫的氯贝酸（CFA）突变体（Ia-mutant）中，IAA 1不能合成IAA，而是积累了吲哚-3-乙醇（IEOH）. <Purification of TATase>通过硫酸铵沉淀、凝胶过滤、DEAE离子交换和亲和层析等方法对这些酶进行纯化，明确了至少存在三种TAT酶同工酶. <Selection of IAA- mutant>通过对抗生长素化合物CFA的抗性筛选获得IAA缺失突变体。在该突变体中，IAA的产生受到显著抑制，IEOH的积累代替了IAA的积累。因此推测CFA处理可能导致编码IAAL单加氧酶的基因发生突变。此外，我们观察到染色体III（暂定名）被分离成两个片段的脉冲场凝胶电泳。少

Similarly to the cases of plant bacterial pathogen, such, as Pseudomonas savastanoi and Agrobacterium tumefaciens, plant fungal hyperplastic pathogen, Taphrina wiesneri, Taphrina deformans and Taphrina pruni, produced high concentrations of IAA and cytokinin that seems to result in disturbing the hormone balance in the host cells followed by the hyperplasia of plant cells.In this research, we elucidated the IAA biosynthetic pathway of Taphrina wiesneri. and purified one of relative enzyme of this pathway to investigate the regulational mechanisms of IAA biosynthesis. Further, we obtained Iaa- mutants and carried out pulse field gel electrophoresis for the genetic analysis of the mutants.1. <Biostnthetic pathway of IAA and their regulation> There are two biosynthetic pathway of IAA in Taphrina wiesneri, namely 1) from L-tryptophan (Trp), indole-3-pyruvic acid (IPA), indole-3-acetaldehyde (IAAL) to IAA, 2) indole-3-aceton-itrile (IAN) to IAA. Although tryptophan amino transferase (TATase … More ) which convertes Trp into IPA is uninducible, IAN nitrilase which :convertes IAN into IAA is inducible. One of the IAA biosynthetic pathways was regulated by the oxidation or reduction of IAA1, because in clofibric acid (CFA) mutant of Taphrina wiesneri (Iaa- mutant) IAA was not synthesized from IAA1, and indole-3-ethanol (IEOH) was accumulated.2. <Purification of TATase> It was clarified that at least three TATase isozymes are present by the purification of these enzymes using arhmonium sulfate precipitation, gel filtration, DEAE ion exchange, and affinity chromatography.3. <Selection of IAA- mutant> IAA deficient mutant was selected by the resistance against anti-auxin compound, CFA. In this mutant, IAA producibility was significant inhibited, and IEOH accumulation was observed instead of IAA. Therefore it was speculated that the treatment with CFA might have caused some mutation in gene encoding IAAL monooxigenase. In addition, we observed that chromosome III (a tentative name) was separated into two fragments by the pulse field gel electrophoresis. Less