Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, S-901 83, Umeå, Sweden.
Planta. 1990 Mar;180(4):562-8. doi: 10.1007/BF02411455.
The compartmentation and metabolism of indole-3-acetic acid (IAA) was examined in protoplasts derived from needles ofPinus sylvestris L., leaves of normal plants ofNicotiana tabacum L., leaves ofN. tabacum plants carrying the T-DNA gene 1 (rG1 plants) and leaves ofN. tabacum plants carrying the T-DNA gene 2 (rG2 plants) by using a rapid cell-fractionation method. In all tissues, 30%-40% of the IAA pool was located in the chloroplast, while the remainder was found in the cytosol. Quantitative analysis of indole-3-ethanol (IEt) showed that in bothPinus andNicotiana the IEt pool was located exclusively in the cytosol. The only plant that contained endogenous indoleacetamide (IAAm) was therG1-mutant ofN. tabacum, expressing theAgrobacterium tumefaciens T-DNA gene 1. Cellular fractionation of protoplasts from this transgenic plant showed that the entire IAAm pool was located in the cytosol. Feeding experiments utilizing [5-(3)H]tryptophan, [5-(3)H]IEt, [1'-(14)C] and [2'-(14)C]IAA demonstrated that the biosynthesis and catabolism of IAA occurred in the cytosol in bothPinus and in the wild type and the different mutants ofNicotiana. Furthermore, the biosynthesis of IAAm in therG1 plants was also shown to be localized in the cytosol.
用快速细胞分离法研究了来源于欧洲赤松针叶、正常烟草叶片、携带 T-DNA 基因 1（rG1 植株）的烟草叶片和携带 T-DNA 基因 2（rG2 植株）的烟草叶片原生质体中吲哚-3-乙酸（IAA）的区室化和代谢。在所有组织中，IAA 库的 30%-40%位于叶绿体中，其余则位于细胞质中。吲哚-3-乙醇（IEt）的定量分析表明，在欧洲赤松和烟草中，IEt 库仅位于细胞质中。唯一含有内源性吲哚乙酰胺（IAAm）的植物是表达根癌农杆菌 T-DNA 基因 1 的 rG1 突变型烟草。该转基因烟草原生质体的细胞分离表明，整个 IAAm 库都位于细胞质中。利用 [5-(3)H]色氨酸、[5-(3)H]IEt、[1'-(14)C]和[2'-(14)C]IAA 进行的饲喂实验表明，IAA 的生物合成和分解代谢发生在细胞质中，在欧洲赤松和野生型以及不同突变型烟草中都是如此。此外，rG1 植株中 IAAm 的生物合成也被证明定位于细胞质中。
