Harrison M J, van Buuren M L
Samuel Roberts Noble Foundation, Plant Biology Division, Ardmore, Oklahoma 73401, USA.
Nature. 1995 Dec 7;378(6557):626-9. doi: 10.1038/378626a0.
Vesicular-arbuscular (VA) mycorrhizal fungi form symbiotic associations with the roots of most terrestrial plants, including many agriculturally important crop species. The fungi colonize the cortex of the root to obtain carbon from their plant host, while assisting the plant with the uptake of phosphate and other mineral nutrients from the soil. This association is beneficial to the plant, because phosphate is essential for plant growth and development, especially during growth under nutrient-limiting conditions. Molecular genetic studies of these fungi and their interaction with plants have been limited owing to the obligate symbiotic nature of the VA fungi, so the molecular mechanisms underlying fungal-mediated uptake and translocation of phosphate from the soil to the plant remain unknown. Here we begin to investigate this process by identifying a complementary DNA that encodes a transmembrane phosphate transporter (GvPT) from Glomus versiforme, a VA mycorrhizal fungus. The function of the protein encoded by GvPT was confirmed by complementation of a yeast phosphate transport mutant. Expression of GvPT was localized to the external hyphae of G. versiforme during mycorrhizal associations, these being the initial site of phosphate uptake from the soil.
泡囊-丛枝（VA）菌根真菌与大多数陆生植物的根系形成共生关系，其中包括许多具有重要农业价值的作物品种。这些真菌定殖于根的皮层，从寄主植物获取碳源，同时帮助植物从土壤中吸收磷和其他矿质养分。这种共生关系对植物有益，因为磷对植物的生长发育至关重要，尤其是在养分限制条件下生长时。由于VA真菌的专性共生特性，对这些真菌及其与植物相互作用的分子遗传学研究受到限制，因此真菌介导的磷从土壤向植物的吸收和转运的分子机制仍不清楚。在这里，我们通过鉴定一种编码来自VA菌根真菌地表球囊霉的跨膜磷转运蛋白（GvPT）的互补DNA，开始研究这一过程。通过酵母磷转运突变体的互补实验证实了GvPT编码蛋白的功能。在菌根共生过程中，GvPT的表达定位于地表球囊霉的外部菌丝，这些菌丝是从土壤中吸收磷的初始部位。
