IDENTIFICATION OF IAA GENES AND ITS REGULATION IN TAPHRINA WIESNERI

与植物细菌性病原体如savastanoi假单胞菌和农杆菌类似，植物真菌增生性病原体taaphrina wiesneri、taaphrina deformans和taaphrina pruni产生高浓度的IAA和细胞分裂素，似乎会扰乱宿主细胞的激素平衡，从而导致植物细胞的增生。在本研究中，我们阐明了水仙IAA的生物合成途径。并纯化了该途径的一个相关酶，探讨IAA生物合成的调控机制。此外，我们获得了Iaa-突变体，并进行了脉冲场凝胶电泳，对突变体进行了遗传分析。< IAA的生物合成途径及其调控>鸢尾草IAA的生物合成途径有两种，即1)l -色氨酸（Trp）、吲哚-3-丙酮酸（IPA）、吲哚-3-乙醛（IAAL）合成IAA， 2)吲哚-3-乙腈（IAN）合成IAA。虽然将色氨酸转化为IPA的色氨酸氨基转移酶（TATase…More）是不可诱导的，但将IAN转化为IAA的IAN腈酶是可诱导的。IAA的生物合成途径之一是受IAA1的氧化或还原调控，这是因为在棉蚜的纤维酸（CFA）突变体（IAA -突变体）中，IAA不是由IAA1合成的，而是积累了吲哚-3-乙醇（IEOH）。通过使用硫酸铵沉淀、凝胶过滤、DEAE离子交换和亲和层析对这些酶进行纯化，明确了至少存在三种TATase同工酶。IAA-突变体>通过抗抗生长素化合物（CFA）筛选IAA缺陷突变体。在该突变体中，IAA的生产能力明显受到抑制，并且观察到IEOH的积累而不是IAA。因此推测CFA治疗可能导致编码IAAL单氧化酶的基因发生突变。此外，我们还观察到，通过脉冲场凝胶电泳，III染色体（暂定名称）被分离成两个片段。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