Characterization of Mycorrhizas Formed by Glomus sp. on Roots of Hypernodulating Mutants of Lotus japonicus
Characterization of Mycorrhizas Formed by Glomus sp. on Roots of Hypernodulating Mutants of Lotus japonicus
复制标题
球囊霉属形成的菌根的表征。
作者：
M. Zakaria Solaiman;K. Senoo;M. Kawaguchi;H. Imaizumi;S. Akao;A. Tanaka;H. Obata
以丛枝菌根真菌Glomus sp.对Lotusjaponicus高调控突变体Ljsym78-1和Ljsym78-2进行了鉴定。突变体在根瘤的系统自动调节和硝酸盐抑制方面存在缺陷，形成过量的根瘤和侧根。丛枝菌根真菌定植的根长百分比显著高于野生型的根。定植的详细评价表明，与野生型相比，突变根中丛枝的定植比例增加，而外部菌丝、内部菌丝和囊泡的定植比例降低。丛枝、外菌丝和内菌丝的琥珀酸脱氢酶活性变化趋势相似。此外，在突变体根上形成的绝大多数单株丛枝具有发育良好且看似坚韧的形态。结果表明，Ljsym78位点的突变促进了丛枝的生长和活性，但导致菌丝的生长和活性降低。我们报道了首次鉴定出的日本莲花丛枝形成显著增加的突变体，并将这些突变体命名为arb++。
Lotusjaponicus hypernodulating mutants, Ljsym78-1 and Ljsym78-2, by the arbuscular mycorrhizal fungus Glomus sp. was characterized. The mutants are defective in systemic autoregulation of nodulation and nitrate inhibition, and form an excess of nodules and lateral roots. The percent root length colonized by the arbuscular mycorrhizal fungi was significantly higher for the mutant than wild-type roots. Detailed assessment of the colonization indicated that the percentage of colonization by arbuscules was increased, but that by external hyphae, internal hyphae and vesicles was decreased, in the mutant roots compared with the wild-type. The succinate dehydrogenase activity of arbuscules, external hyphae and internal hyphae showed similar trends. In addition, the majority of individual arbuscules that formed on the mutant roots had a well-developed and seemingly tough morphology. The results suggest that mutation at the Ljsym78 locus positively stimulates the growth and activity of arbuscules, but leads to reduced growth and activity of hyphae. We report the first identification of Lotus japonicus mutants that show significantly increased arbuscule formation and termed these mutants Arb++.