Powdery mildews are major diseases for a range of crops. The loss of function of specific Mildew Locus O (MLO) genes has long been associated with pre-haustorial plant resistance to powdery mildew and has proven to be durable in several species. Erysiphe pisi is the major causal agent of powdery mildew in pea (Pisum sativum L.) and in the closely related Lathyrus sativus L. and Lathyrus cicera L. PsMLO1 has been extensively studied in pea. However, no MLO gene family members have been isolated and characterized in Lathyrus species so far. In this study, MLO1 genes were isolated and characterized in L. sativus and L. cicera genotypes with varied levels of partial resistance against powdery mildew. Phylogenetic analyses confirmed that Lathyrus MLO1 belongs to Clade V, like all dicot MLO proteins associated with powdery mildew susceptibility. A L. sativus recombinant inbred line population (RIL) was genotyped by sequencing to develop a high-density L. sativus genetic linkage map. DNA sequence polymorphisms between the analyzed genotypes allowed the location of MLO1 in the newly developed L. sativus RIL genetic linkage map. Subsequent comparative mapping between L. sativus and L. cicera genetic maps and P. sativum, Lens culinaris Medik., and Medicago truncatula Gaertn. reference genomes revealed important aspects of the conservation of the MLO1 locus position and of the overall chromosomal rearrangements occurring during legume evolution, with relevance to legume disease resistance breeding programs.

中文翻译：

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Lathyrus 物种中的 MLO1 白粉病易感基因：高密度连锁图在比较作图和同线性分析中的作用

白粉病是一系列作物的主要病害。长期以来，特定霉菌位点 O ( MLO ) 基因的功能丧失与吸毒前植物对白粉病的抗性有关，并已证明在几个物种中具有持久性。Erysiphe pisi是豌豆 ( Pisum sativum L.) 和密切相关的Lathyrus sativus L. 和Lathyrus cicera L. 中白粉病的主要病原体。PsMLO1已在豌豆中得到广泛研究。然而，迄今为止，尚未在Lathyrus物种中分离和表征MLO基因家族成员。在本研究中，MLO1在L. sativus和L. cicera基因型中分离并表征了对白粉病具有不同水平的部分抗性的基因。系统发育分析证实，与所有与白粉病易感性相关的双子叶植物 MLO 蛋白一样，Lathyrus MLO1 属于进化枝 V。甲L.黄瓜重组自交系（RIL）通过测序基因分型以开发出高密度L.黄瓜遗传连锁图。分析的基因型之间的 DNA 序列多态性允许 MLO1 在新开发的L. sativus RIL 遗传连锁图中定位。L. sativus和L. cicera之间的后续比较映射遗传图谱和P. sativum、Lens culinaris Medik. 和Medicago truncatula Gaertn。参考基因组揭示了MLO1基因座位置保守性和豆科植物进化过程中发生的整体染色体重排的重要方面，与豆科植物抗病育种计划相关。