Auxin influences strigolactones in pea mycorrhizal symbiosis

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• 作者：E. Foo ; ^{eloise.foo@utas.edu.au}
• 关键词：bsh ; bushy ; CCD ; carotenoid cleavage dioxygenase ; GR24 ; synthetic strigolactone ; IAA ; indole-3-acetic acid
• 刊名：Journal of Plant Physiology
• 出版年：2013
• 出版时间：15 March, 2013
• 年：2013
• 卷：170
• 期：5
• 页码：523-528
• 全文大小：561 K

文摘

Hormone interactions are essential for the control of many developmental processes, including intracellular symbioses. The interaction between auxin and the new plant hormone strigolactone in the regulation of arbuscular mycorrhizal symbiosis was examined in one of the few auxin deficient mutants available in a mycorrhizal species, the auxin-deficient bsh mutant of pea (Pisum sativum). Mycorrhizal colonisation with the fungus Glomus intraradices was significantly reduced in the low auxin bsh mutant. The bsh mutant also exhibited a reduction in strigolactone exudation and the expression of a key strigolactone biosynthesis gene (PsCCD8). Strigolactone exudation was also reduced in wild type plants when the auxin content was reduced by stem girdling. Low strigolactone levels appear to be at least partially responsible for the reduced colonisation of the bsh mutant, as application of the synthetic strigolactone GR24 could partially rescue the mycorrhizal phenotype of bsh mutants. Data presented here indicates root auxin content was correlated with strigolactone exudation in both mutant and wild type plants. Mutant studies suggest that auxin may regulate early events in the formation of arbuscular mycorrhizal symbiosis by controlling strigolactone levels, both in the rhizosphere and possibly during early root colonisation.