van Ghelue M, Ribeiro A, Solheim B, Akkermans A D, Bisseling T, Pawlowski K
Institute of Biology and Geology, University of Tromso, Tromso, Norway.
Mol Gen Genet. 1996 Mar 7;250(4):437-46. doi: 10.1007/BF02174032.
Two different types of nitrogen-fixing root nodules are known- actinorhizal nodules induced by Frankia and legume nodules induced by rhizobia. While legume nodules show a stem-like structure with peripheral vascular bundles, actinorhizal nodule lobes resemble modified lateral roots with a central vascular bundle. To compare carbon metabolism in legume and actinorhizal nodules, sucrose synthase and enolase cDNA clones were isolated from a cDNA library, obtained from actinorhizal nodules of Alnus glutinosa. The expression of the corresponding genes was markedly enhanced in nodules compared to roots. in situ hybridization showed that, in nodules, both sucrose synthase and enolase were expressed at high levels in the infected cortical cells as well as in the pericycle of the central vascular bundle of a nodule lobe. Legume sucrose synthase expression was studied in indeterminate nodules from pea and determinate nodules from Phaseolus vulgaris by using in situ hybridization.
已知有两种不同类型的固氮根瘤——由弗兰克氏菌诱导形成的放线菌根瘤和由根瘤菌诱导形成的豆科植物根瘤。豆科植物根瘤呈现出具有外周维管束的茎状结构，而放线菌根瘤叶则类似于具有中央维管束的变态侧根。为了比较豆科植物根瘤和放线菌根瘤中的碳代谢，从一个由欧洲桤木放线菌根瘤构建的cDNA文库中分离出蔗糖合酶和烯醇酶的cDNA克隆。与根相比，相应基因在根瘤中的表达显著增强。原位杂交显示，在根瘤中，蔗糖合酶和烯醇酶在受感染的皮层细胞以及根瘤叶中央维管束的中柱鞘中均高水平表达。通过原位杂交研究了豌豆的不定根瘤和菜豆的定根瘤中豆科植物蔗糖合酶的表达。
