Fernandez-Lopez M, Goormachtig S, Gao M, D'Haeze W, Holsters M
Laboratorium voor Genetica, Departement Genetica, Vlaams Interuniversitair Instituut voor Biotechnologie (VIB), Universiteit Gent, K.L. Ledeganckstraat 35, B-9000 Ghent, Belgium.
Proc Natl Acad Sci U S A. 1998 Oct 13;95(21):12724-8. doi: 10.1073/pnas.95.21.12724.
Leguminous plants in symbiosis with rhizobia form either indeterminate nodules with a persistent meristem or determinate nodules with a transient meristematic region. Sesbania rostrata was thought to possess determinate stem and root nodules. However, the nature of nodule development is hybrid, and the early stages resemble those of indeterminate nodules. Here we show that, depending on the environmental conditions, mature root nodules can be of the indeterminate type. In situ hybridizations with molecular markers for plant cell division, as well as the patterns of bacterial nod and nif gene expression, confirmed the indeterminate nature of 30-day-old functional root nodules. Experimental data provide evidence that the switch in nodule type is mediated by the plant hormone ethylene.
与根瘤菌共生的豆科植物会形成具有持续分生组织的不定型根瘤或具有短暂分生区域的定型根瘤。喙田菁被认为具有定型的茎瘤和根瘤。然而，根瘤发育的本质是混合型的，其早期阶段类似于不定型根瘤。我们在此表明，根据环境条件，成熟的根瘤可以是不定型的。利用植物细胞分裂分子标记进行的原位杂交，以及细菌结瘤基因和固氮基因的表达模式，证实了30日龄功能性根瘤的不定型本质。实验数据提供了证据，表明根瘤类型的转变是由植物激素乙烯介导的。
