Characterization of LeMir, a root-knot nematode-induced gene in tomato with an encoded product secreted from the root
Characterization of LeMir, a root-knot nematode-induced gene in tomato with an encoded product secreted from the root
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DOI：
10.1104/pp.118.1.237
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发表时间：
1998-09-01
期刊：
影响因子：
7.4
通讯作者：
Williamson, VM
中科院分区：
文献类型：
--
作者：
Brenner, ED;Lambert, KN;Williamson, VM
番茄（Lycopersicon esculentum Mill.）与根结线虫（Meloidogynejavanica）感染的线虫编码与神秘果蛋白具有54%氨基酸同一性的蛋白质，神秘果蛋白是一种使酸性物质被感知为甜味的无味蛋白质。因此，该基因被命名为LeMir（L.奇异果素（miraculin）。序列相似性将编码的蛋白质置于大豆胰蛋白酶抑制剂家族（Kunitz）中。LeMir mRNA存在于根、下胚轴和花组织中，在根中表达最高。线虫感染后表达的快速诱导定位于根尖。原位杂交结果表明，LeMir基因在根冠和根尖表皮中组成型表达。LeMir蛋白产物（LeMir）在酵母巴斯德毕赤酵母中产生以用于产生抗体。Western-blot分析表明，LeMir的表达上调线虫感染和创伤。LeMir也在番茄愈伤组织中表达。免疫印迹分析表明，LeMir在整个幼苗根中表达，但在根/芽交界处表达水平最高。对幼苗根系分泌物的分析表明，LeMir从根部分泌到周围环境中，这表明它可能与土传微生物相互作用。
A tomato gene that is induced early after infection of tomato (Lycopersicon esculentum Mill.) with root-knot nematodes (Meloidogyne javanica) encodes a protein with 54% amino acid identity to miraculin, a flavorless protein that causes sour substances to be perceived as sweet. This gene was therefore named LeMir (L. esculentum miraculin). Sequence similarity places the encoded protein in the soybean trypsin-inhibitor family (Kunitz). LeMir mRNA is found in root, hypocotyl, and flower tissues, with the highest expression in the root. Rapid induction of expression upon nematode infection is localized to root tips. In situ hybridization shows that LeMir is expressed constitutively in the root-cap and root-tip epidermis. The LeMir protein product (LeMir) was produced in the yeast Pichia pastoris for generation of antibodies. Western-blot analysis showed that LeMir expression is up-regulated by nematode infection and by wounding. LeMir is also expressed in tomato callus tissue. Immunoprint analysis revealed that LeMir is expressed throughout the seedling root, but that levels are highest at the root/shoot junction. Analysis of seedling root exudates revealed that LeMir is secreted from the root into the surrounding environment, suggesting that it may interact with soil-borne microorganisms.