Plant Growth-Promoting Fungus, Trichoderma koningi Suppresses Isoflavonoid Phytoalexin Vestitol Production for Colonization on/in the Roots of Lotus japonicus
Plant Growth-Promoting Fungus, Trichoderma koningi Suppresses Isoflavonoid Phytoalexin Vestitol Production for Colonization on/in the Roots of Lotus japonicus
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DOI：
10.1264/jsme2.me10176
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发表时间：
2011-06-01
影响因子：
2.2
通讯作者：
Takenaka, Shigehito
中科院分区：
文献类型：
--
作者：
Masunaka, Akira;Hyakumachi, Mitsuro;Takenaka, Shigehito
分析了植物生长促进真菌(PGPF)对莲花的定殖与豆科植物的主要防御反应--异黄酮类植保素前庭醇生物合成的关系。将含有康氏木霉、木霉和简单青霉的PGPF接种到日本落叶松的根部，只有康宁木霉能在根部长期定植，使植株干重增加126%。科宁木霉定植的根部横切面的显微镜观察显示，细胞间菌丝生长并形成酵母样细胞。通过对植物前庭醇合成相关基因的Northern分析和植物前庭醇合成的高效液相色谱分析，研究了真菌侵染对植物防御系统的诱导作用。接种共生的洛提中生根瘤菌没有诱导转录本的任何积累。柯宁支原体立即抑制转录水平，使之达到洛提分枝杆菌诱导的转录水平。科宁木根中测得的前庭激素与洛提根中测得的相当。其他对大豆致病的PGPF和CalonecVictoria ilicola可刺激基因的持续表达和前庭分泌物的分泌。这些PGPF在共生关系的建立上类似于菌根真菌，而不是真菌寄生。
The relationship between the colonization of Lotus japonicus by plant growth-promoting fungi (PGPF) and biosynthesis of the isoflavonoid phytoalexin vestitol, a major defensive response of leguminous plants, was analyzed. When PGPF including Trichoderma koningi, Fusarium equiseti, and Penicillium simplicissimum were inoculated onto L. japonicus roots, only T. koningi colonized the roots long-term and increased plant dry weight (126%). Microscopic observations of transverse sections of roots colonized by T. koningi demonstrated intercellular hyphal growth and the formation of yeast-like cells. The induction of plant defenses by fungal infections was examined by Northern analysis of genes involved in vestitol biosynthesis and HPLC of vestitol production in L. japonicus. Inoculation with symbiotic Mesorhizobium loti did not induce any accumulation of the transcripts. T. koningi immediately suppressed transcript levels to those induced by M. loti. The vestitol transuded from roots by T. koningi was detected at a level equivalent to that transuded by M. loti. Other PGPF and Calonectoria ilicola pathogenic to soybean but not to L. japonicus, stimulated continuous expression of genes and exudation of vestitol. These PGPF resembled mycorrhizal fungi in the establishment of symbiotic associations rather than fungal parasites.