The trichothecene mycotoxin deoxynivalenol facilitates cell-to-cell invasion during wheat-tissue colonisation by Fusarium graminearum
The trichothecene mycotoxin deoxynivalenol facilitates cell-to-cell invasion during wheat-tissue colonisation by Fusarium graminearum
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单端孢菌素真菌毒素脱氧雪腐镰刀菌烯醇促进禾谷镰刀菌在小麦组织定植期间的细胞间侵袭
DOI：
10.1101/2023.12.05.570169
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Armer V
中科院分区：
文献类型：
--
作者：
Armer V
小粒谷物上的镰刀菌赤霉病主要由子囊菌真菌病原体禾谷镰刀菌引起。花穗组织感染的特点是强效单端孢霉烯真菌毒素的生物合成和分泌，其中脱氧雪腐镰刀菌烯醇（DON）因其对谷物质量和消费者安全的负面影响而被广泛报道。 TRI5基因编码DON生物合成途径中的一种必需酶，并且单基因缺失突变体ΔTri5被广泛报道可以限制接种小穗的疾病进展。在这项研究中，我们提出了新的生物成像证据，表明 DON 促进胞间连丝穿过细胞壁，这是成功定植宿主组织所必需的过程。 ΔTri5 的化学互补并没有恢复宏观或微观表型，表明 DON 分泌在空间和时间上受到严格调节。比较定性和定量形态学细胞分析表明感染对植物细胞壁厚度没有影响。感染期间胞间连丝处胼胝质的免疫标记表明，当外源施用时，DON 可以增加沉积物，但当存在禾谷镰刀菌菌丝时，沉积物会减少。这项研究强调了霉菌毒素产生、细胞壁结构和胞间连丝在这种高度专业化的相互作用中相互关联的作用的复杂性。
Fusarium head blight disease on small‐grain cereals is primarily caused by the ascomycete fungal pathogenFusarium graminearum. Infection of floral spike tissues is characterized by the biosynthesis and secretion of potent trichothecene mycotoxins, of which deoxynivalenol (DON) is widely reported due to its negative impacts on grain quality and consumer safety. TheTRI5gene encodes an essential enzyme in the DON biosynthesis pathway and the single gene deletion mutant, ΔTri5, is widely reported to restrict disease progression to the inoculated spikelet. In this study, we present novel bioimaging evidence revealing that DON facilitates the traversal of the cell wall through plasmodesmata, a process essential for successful colonization of host tissue. Chemical complementation of ΔTri5did not restore macro‐ or microscopic phenotypes, indicating that DON secretion is tightly regulated both spatially and temporally. A comparative qualitative and quantitative morphological cellular analysis revealed infections had no impact on plant cell wall thickness. Immunolabelling of callose at plasmodesmata during infection indicates that DON can increase deposits when applied exogenously but is reduced whenF.graminearumhyphae are present. This study highlights the complexity of the interconnected roles of mycotoxin production, cell wall architecture and plasmodesmata in this highly specialized interaction.