Park Seijin, Cohen Jerry D, Slovin Janet P
Department of Horticultural Science and Microbial and Plant Genomics Institute, University of Minnesota, St. Paul, MN 55108, USA.
Planta. 2006 Oct;224(5):1015-22. doi: 10.1007/s00425-006-0287-z. Epub 2006 May 9.
Achenes and receptacle tissue of Fragaria vesca, L. cultivar Yellow Wonder were shown to contain conjugated indole-3-acetic acid (IAA) that was not soluble in organic solvents and yielded IAA after strong alkaline hydrolysis, suggestive of IAA attached to plant proteins. This solvent insoluble conjugated IAA accounted for between 0.4 and 4 ng of IAA per gram fresh weight of tissue in both achenes and receptacles. To investigate this strawberry conjugate class further, a polyclonal antibody was produced to IAA-glycine attached to BSA that detected neutral indole acid esters, monocarboxylic-amino acid IAA conjugates and IAA proteins. Using immunoblotting, both achenes and receptacles of strawberry were shown to have primarily an immuno-detectable band at 76 kDa. Two-dimensional polyacrylamide gel electrophoresis yielded a wide band that was analyzed by LC-MS/MS analysis following in-gel trypsin digestion. Peptides derived from the immuno-detectable band were tentatively identified by peptide fragment analysis as being from either a chaperonin related to the hsp60 class of proteins or, alternatively, an ATP synthase. This is one of the first reports of an IAA modified protein in fruit tissue.
研究表明，野草莓（Fragaria vesca, L.）品种“黄奇迹”的瘦果和花托组织中含有共轭吲哚 - 3 - 乙酸（IAA），这种共轭IAA不溶于有机溶剂，在强碱水解后产生IAA，这表明IAA与植物蛋白相连。这种不溶于溶剂的共轭IAA在瘦果和花托组织中每克鲜重含有0.4至4纳克IAA。为了进一步研究这种草莓共轭物类别，制备了一种针对与牛血清白蛋白（BSA）相连的IAA - 甘氨酸的多克隆抗体，该抗体可检测中性吲哚酸酯、单羧酸 - 氨基酸IAA共轭物和IAA蛋白。通过免疫印迹法显示，草莓的瘦果和花托主要在76 kDa处有一条可免疫检测的条带。二维聚丙烯酰胺凝胶电泳产生了一条宽带，在凝胶内胰蛋白酶消化后通过液相色谱 - 串联质谱（LC - MS/MS）分析。通过肽片段分析初步鉴定，来自可免疫检测条带的肽要么来自与hsp60类蛋白相关的伴侣蛋白，要么来自ATP合酶。这是关于果实组织中IAA修饰蛋白的首批报道之一。
