As an obligate parasite, Puccinia striiformis f. sp. tritici (Pst) forms haustoria to obtain nutrients from plant cells for development, and these structures are essential for pathogen survival. To better understand the contribution of haustoria to the interactions with the host plants, we isolated haustoria from susceptible wheat leaves infected with Pst race CYR31 and sequenced their transcriptome as well as those of urediospores and germ tubes, and compared the three transcriptomes. A total of 3524 up‐regulated genes were obtained from haustoria, of which 73 genes were related to thiamine biosynthesis, glycolysis and lipid metabolic processes. Silencing seven of the genes reduced the growth and development of Pst in wheat. More interestingly, 1197 haustorial secreted proteins (HASPs) were detected in haustoria, accounting for 34% of the total proteins, indicating that these HASPs play important roles in haustorium‐mediated pathogenic progression. Furthermore, 69 HASPs were able to suppress Bax‐triggered programmed cell death in tobacco. Additionally, 46 HASPs significantly reduced callose deposition in wheat using the type III secretion system. This study identified a large number of effectors through transcriptome sequencing, and the results revealed components of metabolic pathways that impact the growth and colonization of the pathogen and indicate essential functions of haustoria in the growth and pathogenicity of Pst.

中文翻译：

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Haustoria-小麦和小麦条锈菌相互作用期间的武库。sp。小麦。

作为专性寄生虫，Puccinia striiformis f。sp。Tritici（Pst）形成haustoria以从植物细胞获取营养以进行发育，而这些结构对于病原体的生存至关重要。为了更好地了解haustoria对与宿主植物相互作用的贡献，我们从感染了Pst种CYR31的易感小麦叶片中分离了haustoria，并对它们的转录组以及复孢子和胚芽管的转录组进行了测序，并比较了三个转录组。从haustoria获得了总共3524个上调基因，其中73个基因与硫胺素的生物合成，糖酵解和脂质代谢过程有关。使七个基因沉默会降低Pst的生长和发育在小麦中。更有趣的是，在手风琴中检出了1197个手电筒分泌蛋白（HASPs），占总蛋白的34％，这表明这些HASPs在手风琴介导的致病性进展中起着重要作用。此外，有69种HASP能够抑制烟草中Bax触发的程序性细胞死亡。此外，使用III型分泌系统，有46种HASP显着减少了小麦中的愈伤组织沉积。这项研究通过转录组测序确定了大量效应子，结果揭示了代谢途径的组成部分，这些代谢途径影响病原体的生长和定殖，并表明haustoria在Pst的生长和致病性中的基本功能。