Chromosome constitution of hybrid strains constructed by protoplast fusion between the tomato and strawberry pathotypes of Alternaria alternata
Chromosome constitution of hybrid strains constructed by protoplast fusion between the tomato and strawberry pathotypes of Alternaria alternata
复制标题
DOI：
10.1007/s10327-009-0149-1
复制
发表时间：
2009-04-01
影响因子：
1.2
通讯作者：
Kodama, Motoichiro
中科院分区：
文献类型：
--
作者：
Akagi, Yasunori;Taga, Masatoki;Kodama, Motoichiro
为了研究烟草赤星病菌（Alternaria alternata）寄主特异性毒素产生的遗传规律及其与致病性的关系，建立了一种原生质体融合系统。将A. alternata番茄致病型（AAL毒素产生菌）和A. alternata草莓致病型（AF-毒素产生者）通过电融合进行融合。在检测的5个融合菌株中，2个菌株对番茄和草莓寄主植物都具有致病性，而其余的融合菌株仅对番茄具有致病性。脉冲场凝胶电泳分析表明，番茄和草莓的杂交菌株致病携带1.0-和1.05-Mb的有条件地重复（CD）的染色体，分别来自亲本株的番茄和草莓pathotypes。另一方面，融合株似乎仅保留了一条来自亲本株之一的同源染色体（在必需染色体（A染色体）的情况下）。结果表明，两种不同致病型的融合株是一种致病型的融合株。Alternata可能是由于融合核中额外的必需染色体组缺失而导致的单倍体，而来自每个亲本菌株的CD染色体可以稳定地保持在新的遗传背景中，具有扩大的致病性范围。
To analyze the genetics of host-specific toxin production and its relation to the specific pathogenicity of a mitosporic fungus Alternaria alternata, we developed a protoplast fusion system. Protoplasts of drug-resistant transformants of the A. alternata tomato pathotype (AAL-toxin producer) and A. alternata strawberry pathotype (AF-toxin producer) were fused by electrofusion. Of five fusion strains examined, two strains were pathogenic on both tomato and strawberry host plants, whereas the rest of the fusion strains were pathogenic only on tomato. Pulsed-field gel electrophoresis analysis demonstrated that the hybrid strains pathogenic on both tomato and strawberry carry 1.0- and 1.05-Mb conditionally dispensable (CD) chromosomes derived, respectively, from the parental strains of the tomato and strawberry pathotypes. On the other hand, the fusion strains appeared to maintain only a single homologous chromosome derived from one of the parental strain in the case of essential chromosomes (A chromosomes). The results suggest that fusion strains between two different pathotypes of A. alternata might be haploid resulting from the deletion of extra sets of essential chromosomes in the fused nuclei, whereas the CD chromosomes derived from each parental strain could be maintained stably in a new genetic background with an expanded range of pathogenicity.