A novel gene whose expression in Medicago truncatula roots is suppressed in response to colonization by vesicular-arbuscular mycorrhizal (VAM) fungi and to phosphate nutrition
A novel gene whose expression in Medicago truncatula roots is suppressed in response to colonization by vesicular-arbuscular mycorrhizal (VAM) fungi and to phosphate nutrition
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DOI：
10.1023/a:1005841119665
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发表时间：
1997-05-01
影响因子：
5.1
通讯作者：
Harrison, MJ
中科院分区：
文献类型：
--
作者：
Burleigh, SH;Harrison, MJ
一个cDNA克隆（Mt4）分离的差异筛选的结果，以确定基因显示在蒺藜苜蓿和泡状丛枝菌根（VAM）真菌Glomus versiforme之间的相互作用过程中改变表达。Mt4表示M。Truncatula mRNA含有许多短的开放阅读框，其中最长的两个被预测为每个编码51个氨基酸的多肽。其中一个开放阅读框与番茄中的磷酸盐饥饿诱导基因有一个短的相同区域。Mt4基因表达受菌根真菌定植的调控：在未定植的根中检测到转录本，并且在两种M. truncatula和M. sativa（alfalfa）根系中的G. versiforme。在G. versiforme和M. sativa mycorrhizal minus（myc（-））株系中表达，表明该基因的下调发生在真菌与其寄主植物互作的早期。营养培养基中的磷酸盐水平也影响Mt4基因的表达：转录本存在于缺磷条件下生长的植物的根中，但在磷酸盐充足条件下生长的植物的根中检测不到。此外，只有当植物在氮充足的条件下生长时才观察到表达。北方印迹分析表明Mt4转录本主要存在于根中，在茎或叶中几乎检测不到。因此，Mt4表示M。响应于菌根真菌的定殖和植物，调节蒺藜的表达。
A cDNA clone (Mt4) was isolated as a result of a differential screen to identify genes showing altered expression during the interaction between Medicago truncatula and the vesicular-arbuscular mycorrhizal (VAM) fungus Glomus versiforme. Mt4 represents a M. truncatula mRNA that contains numerous short open reading frames, the two longest of which are predicted to encode polypeptides of 51 amino acids each. One of these open reading frames shares a short region of identity with a phosphate starvation-inducible gene from tomato. Mt4 gene expression is regulated in response to colonization by mycorrhizal fungi: transcripts were detected in non-colonized roots and levels decreased in both M. truncatula and M. sativa (alfalfa) roots after colonization by G. versiforme. Transcript levels also decreased during the incomplete interaction between G. versiforme and a M. sativa mycorrhizal minus (myc(-)) line, indicating that the down-regulation of this gene occurs early during the interaction between the fungus and its host plant. Phosphate levels in the nutrient media also affected the expression of the Mt4 gene: transcripts were present in the roots of plants grown under phosphate-deficient conditions, but were undetectable in the roots of plants grown under phosphate sufficient conditions. Furthermore, expression was only observed when plants were grown under nitrogen-sufficient conditions. Northern blot analyses indicate that Mt4 transcripts are present primarily in roots and barely detectable in stems or leaves. Thus, Mt4 represents a M. truncatula expression is regulated in response to both colonization by mycorrhizal fungi and to the plant.