Desoignies N, Stocco C, Bragard C, Legrève A
Université Catholique de Louvain, Louvain-la-Neuve, Belgium.
Commun Agric Appl Biol Sci. 2010;75(2):23-5.
Little is known about the genome of Polymyxa betae and its interactions with sugar beet, due partly to the obligate nature of the protist and the patents on Beta vulgaris sequences. The identification of an ecotype of Arabidopsis thaliana compatible with the protist would help to improve this knowledge. The infection and development of P. betae in 14 worldwide ecotypes of A. thaliana were studied. The detection of plasmodia and resting spores and the production of zoospores in the roots of A. thaliana were obtained in three bioassays, using automatic immersion systems and individual glass tubes. Detection was done using molecular detection and microscopy. Compatible interactions were established between 13 A. thaliana ecotypes of the 14 that were tested and the monosporosoric Belgian strain of P. betae, A26-41. The ecotype Cvi-0 (N1096), from the Cape Verde Islands, was the most compatible with the protist. This ecotype is also susceptible to Plasmodiophora brassicae, another plasmodiophorid. Polymyxa betae infection in A. thaliana was relatively very low compared with B. vulgaris, but every stage of the life cycle of the protist was present. The spore-forming phase was promoted at the expense of the sporangial phase, probably caused by the stress of this new environment. In addition, the protist revealed a new phenotype. This new model study will allow molecular tools available for A. thaliana to be used in order to gain a better understanding of the P. betae-plant interaction during the spore-forming phase.
由于这种原生生物的专性本质以及甜菜（Beta vulgaris）序列的专利问题，人们对甜菜多黏菌（Polymyxa betae）的基因组及其与甜菜的相互作用了解甚少。鉴定一种与该原生生物相容的拟南芥（Arabidopsis thaliana）生态型将有助于增进这方面的认识。研究了甜菜多黏菌在14种全球范围的拟南芥生态型中的感染和发育情况。在三项生物测定中，使用自动浸没系统和单个玻璃管，在拟南芥根部检测到了原质团和休眠孢子，并获得了游动孢子的产生情况。检测通过分子检测和显微镜观察进行。在所测试的14种拟南芥生态型中的13种与甜菜多黏菌的单孢子比利时菌株A26 - 41之间建立了相容的相互作用。来自佛得角群岛的生态型Cvi - 0（N1096）与该原生生物最为相容。这种生态型对另一种根肿菌纲生物——芸薹根肿菌（Plasmodiophora brassicae）也敏感。与甜菜相比，拟南芥中甜菜多黏菌的感染相对非常低，但该原生生物生命周期的每个阶段都存在。孢子形成阶段以牺牲孢子囊阶段为代价得到促进，这可能是由这种新环境的压力导致的。此外，该原生生物呈现出一种新的表型。这项新的模型研究将使可用于拟南芥的分子工具得以应用，以便更好地了解孢子形成阶段甜菜多黏菌与植物的相互作用。
