Tomato sugar transporter genes associated with mycorrhiza and phosphate
Tomato sugar transporter genes associated with mycorrhiza and phosphate
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与菌根和磷酸盐相关的番茄糖转运基因
DOI：
10.1007/s10725-008-9266-7
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发表时间：
2008-06-01
影响因子：
4.2
通讯作者：
Xu, Guohua
中科院分区：
文献类型：
--
作者：
Ge, Lei;Sun, Shubin;Xu, Guohua
在丛枝菌根（AM）共生中，共生伙伴之间存在互惠的营养交换。AM真菌帮助植物从土壤中吸收矿物质营养，特别是磷酸盐（Pi）。作为回报，宿主植物为真菌提供糖。相对于磷在丛枝菌根中的共生运输的研究，很少有专门研究AM共生中糖的运输。利用逆转录酶PCR（RT-PCR）技术分析了菌根和磷对番茄7个糖转运蛋白基因表达的影响。在接种AM真菌Glomus caledonium和Glomus intraradices的根中，分别被归类为假定的蔗糖和己糖转运基因的LeSUT 1和LeHT 2的表达被下调。未预料到的是，LeST 3，一个假定的单糖转运蛋白基因，在根和叶中的表达被接种球囊霉caledonium降低，但被接种球囊霉intraradices增强。高磷处理降低了番茄根系中LeHT 2和LeST 3的表达，提高了叶片中LeHT 2的表达。LeST 3在AM共生过程中表达的矛盾调控表明，在菌根侵染过程中可能发生不同的相互作用，番茄中存在着相当复杂的糖转运蛋白基因的表达调控。
In arbuscular mycorrhizal (AM) symbiosis, there is a reciprocal nutrient exchange between symbiotic partners. AM fungi assist the plants with uptake of mineral nutrients from the soil, especially phosphate (Pi). The host plants, in return, provide the fungi with sugar. In contrast to the studies on the symbiotic transport of Pi in arbuscular mycorrhiza, there have been few investigations devoted specifically to sugar transport in AM symbiosis. Using reverse transcriptase PCR (RT-PCR), we analyzed the effects of mycorrhiza and Pi on the expression of seven putative sugar transporter genes in tomato plants. The expression ofLeSUT1andLeHT2, classified, respectively, as putative sucrose and hexose transporter genes, were down-regulated in the roots inoculated with AM fungiGlomus caledoniumorGlomus intraradices. Unexpectedly, the expression ofLeST3, a putative monosaccharide transporter gene, was decreased by inoculation ofGlomus caledonium, but was enhanced by inoculation ofGlomus intraradicesin both the roots and leaves. High-Pi in the tomato decreased the expression ofLeHT2andLeST3in the roots, and enhanced that ofLeHT2in the leaves. The contradictory regulation of the expression ofLeST3in the AM symbiosis indicates that different interaction may take place during mycorrhizal colonization, and a quite complicated regulation of expression of the sugar transporter genes exist in mycorrhizal tomato.