AUXIN OVERPRODUCER MUTANTS OF HEBELOMA-CYLINDROSPORUM ROMAGNESI HAVE INCREASED MYCORRHIZAL ACTIVITY
AUXIN OVERPRODUCER MUTANTS OF HEBELOMA-CYLINDROSPORUM ROMAGNESI HAVE INCREASED MYCORRHIZAL ACTIVITY
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DOI：
10.1111/j.1469-8137.1994.tb04029.x
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发表时间：
1994-12-01
期刊：
影响因子：
9.4
通讯作者：
DEBAUD, JC
中科院分区：
文献类型：
--
作者：
GAY, G;NORMAND, L;DEBAUD, JC
研究了吲哚-3-乙酸(IAA)高产突变体及其单核和双核后代的外生菌根活力(以单株菌根数表示)，旨在阐明IAA在建立外生菌根共生中的作用。从H1单核体获得的原始突变体比野生型产生了更多的菌根。对导致IAA过量产生的FIR(氟吲哚抗性)突变杂合子合成的双核体的菌根活性研究表明，这些突变是隐性的。它们的平均菌根活性高于非过量生产的菌根，这表明，尽管同胞单核体的菌根活性受多基因控制，但高IAA产量有利于菌根的形成。由FIR突变纯合子合成的双核体形成的菌根数量高于野生型菌丝体，证实了这一点。单核或双核野生型菌根的特征是单列哈蒂格网络，而IAA高产突变体形成的菌根则是多列菌根。突变体对寄主植物的刺激程度与野生型相同，表明生长刺激不是真菌生长素产生的直接结果。讨论了这些突变体作为研究真菌IAA在菌根形成中的作用的模型的有用性。
The ectomycorrhizal activity (expressed as the number of mycorrhizas per plant) of indole-3-acetic acid (IAA) overproducer mutants of Hebeloma cylindrosporum Romagnesi and of their mono- and dikaryotic progenies has been studied in an attempt to clarify the role of fungal IAA in the establishment of ectomycorrhizal symbiosis. The original mutants obtained from the h1 monokaryon produced a higher number of mycorrhizas than did the wild type. The study of the mycorrhizal activity of synthesized dikaryons heterozygous for the FIR (fluoroindole-resistant) mutations, which are responsible for IAA overproduction, showed that these mutations are recessive.The in vitro fruiting of a dikaryon heterozygous for a FIR mutation allowed the isolation of IAA-overproducing sib-monokaryons. Their average mycorrhizal activity was higher than that of non-overproducers, indicating that, although the mycorrhizal activity of sib-monokaryons is under polygenic control, high IAA production gives an advantage in mycorrhiza formation. This was confirmed by the higher number of mycorrhizas formed by synthesized dikaryons homozygous for a FIR mutation than by wild type mycelia.The mycorrhizas formed by the mono- or dikaryotic wild types were characterized by a uniseriate Hartig net, whereas it was pluriseriate in the case of mycorrhizas formed by IAA overproducer mutants. The mutants stimulated the growth of the host plants to the same extent as did the wild types, indicating that growth stimulation is not a direct consequence of fungal auxin production. The usefulness of these mutants as a model to study the role of fungal IAA in mycorrhiza formation is discussed.