Root exudates stimulate the uptake and metabolism of organic carbon in germinating spores of Glomus intraradices

Autor: Gerald Nagahashi, Yair Shachar-Hill, Heike Bücking, Marie Tala, Jehad Abubaker, Peter J. Lammers, Philip E. Pfeffer, Manjula Govindarajulu
Rok vydání: 2008
Předmět:
Zdroj: New Phytologist. 180:684-695
ISSN: 1469-8137
0028-646X
DOI: 10.1111/j.1469-8137.2008.02590.x
Popis: Summary • Root exudates play a key role during the presymbiotic growth phase and have been shown to stimulate hyphal branching and the catabolic metabolism of arbuscular mycorrhizal (AM) fungal spores. • Here, the effect of root exudates on presymbiotic growth, uptake of exogenous carbon and transcript levels for genes putatively involved in the carbon metabolism of germinating spores were determined. • Crude root exudates led to a slight acceleration of spore germination, increased germ tube branching and stimulated uptake and catabolic metabolism of acetate, and to a greater extent of glucose, but had no effect on gene expression. By contrast, partially purified root exudates increased the transcript levels of acyl-CoA dehydrogenase (s-oxidation of fatty acids to acetyl-CoA), malate synthase (glyoxylate cycle) and glutamine-fructose-6-phosphate aminotransferase (chitin biosynthesis), but did not differ from crude root exudates in their effect on substrate uptake and respiration. The expression of glycogen synthase (glycogen biosynthesis), glucose-6-phosphate dehydrogenase (pentose phosphate pathway) and neutral trehalase (hydrolysis of trehalose) were only marginally or not affected by root exudates. • Root exudates have an effect on both membrane activity and gene expression and the results are discussed in relation to the catabolic and anabolic metabolism of spores during presymbiotic growth.
Databáze: OpenAIRE
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