Rudawska M L, Kieliszewska-Rokicka B
Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland.
New Phytol. 1997 Nov;137(3):509-517. doi: 10.1046/j.1469-8137.1997.00838.x.
IAA production by the ectomycorrhizal fungus Paxillus invotutus grown in pure culture was investigated by testing IAA accumulation or IAA-synthesizing activity. All the Paxillus involutus strains studied released indole compounds either when incubated with 0.5 mM tryptophan or in its absence. HPLC analyses of indole compounds all yielded two main peaks identified by reference to controls as being IAA and indole-3-carboxylic acid and a small peak of indole-3-aldehyde. Mass spectrometry unequivocally confirmed IAA production in the culture filtrates and in the incubation solution used to study in vitro IAA-synthesizing activity. The IAA-synthesizing activity was found to vary widely, from 7.6 to 137.4 nmol IAA h g f. wt, between strains. The mycorrhizal activity of these strains with seedlings of Pinus sylvestris cultured under aseptic conditions was tested. Fungal strains that were characterized in pure culture conditions by high LAA-synthesizing activity induced more fine roots and significantly higher numbers of mycorrhizas than strains which showed a low activity of IAA synthesizing enzymes. The increased ectomycarrhiza formation was generally accompanied by an increased growth of seedlings.
通过测试吲哚-3-乙酸（IAA）积累或IAA合成活性，研究了纯培养条件下外生菌根真菌卷缘桩菇（Paxillus involutus）产生IAA的情况。所有研究的卷缘桩菇菌株在与0.5 mM色氨酸一起孵育时或在无色氨酸的情况下都会释放吲哚化合物。对吲哚化合物的高效液相色谱分析均产生了两个主峰，通过与对照比较鉴定为IAA和吲哚-3-羧酸，还有一个吲哚-3-醛的小峰。质谱明确证实了在培养滤液和用于研究体外IAA合成活性的孵育溶液中产生了IAA。发现IAA合成活性在不同菌株之间差异很大，从7.6到137.4 nmol IAA h g鲜重。测试了这些菌株与在无菌条件下培养的樟子松幼苗形成菌根的活性。在纯培养条件下以高IAA合成活性为特征的真菌菌株比那些IAA合成酶活性低的菌株诱导出更多的细根和显著更多的菌根。外生菌根形成的增加通常伴随着幼苗生长的增加。
