Epiphytic proliferation of Zymoseptoria tritici isolates on resistant wheat leaves
Epiphytic proliferation of Zymoseptoria tritici isolates on resistant wheat leaves
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DOI：
10.1016/j.fgb.2023.103822
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发表时间：
2023-06-29
影响因子：
3
通讯作者：
Gurr, S. J.
中科院分区：
文献类型：
--
作者：
Fones, H. N.;Soanes, D.;Gurr, S. J.
小麦病原菌Zymoseptoria triumphium能够在入侵前长时间地附生生长。研究表明，致病菌株在这种附生生长的程度、持续时间和生长形式上各不相同，并且观察到真菌通过出芽和叶面菌丝的营养融合进行无性繁殖等行为。这种附生定殖已被调查很少在相互作用中，分离的Z。如在无毒期间所发生的那样，三聚体不能定殖在质外体上。然而，无毒分离物已被视为经历有性杂交的叶渗透的缺乏，它被广泛接受的是，主要的区别点之间的有毒和无毒分离物发生在试图叶渗透或试图质外体生长，这在无毒的情况下失败的点。在这项工作中，我们描述了广泛的附生生长在三个菌株是无法或具有非常有限的能力，侵入叶，并显示，生长形式是可变的完全毒力菌株。我们证明，在某些相互作用，Z。三尖杉分离物很少侵入叶片并形成分生孢子，但诱导坏死。这些菌株能够实现更高的附生生物量比完全有毒的菌株在无症状的增长，并可能会经历非常广泛的无性繁殖的叶片表面。这些发现对诸如Z是否以及如何产生这些问题具有重要意义。小麦在叶面上获得营养物质，并与小麦防御系统相互作用。
The wheat pathogen Zymoseptoria tritici is capable of a long period of pre-invasive epiphytic growth. Studies have shown that virulent isolates vary in the extent, duration and growth form of this epiphytic growth, and the fungus has been observed to undergo behaviours such as asexual reproduction by budding and vegetative fusion of hyphae on the leaf surface. This epiphytic colonisation has been investigated very little during interactions in which an isolate of Z. tritici is unable to colonise the apoplast, as occurs during avirulence. However, avirulent isolates have been seen to undergo sexual crosses in the absense of leaf penetration, and it is widely accepted that the main point of distinction between virulent and avirulent isolates occurs at the point of attempted leaf penetration or attempted apoplastic growth, which fails in the avirulent case. In this work, we describe extensive epiphytic growth in three isolates which are unable or have very limited ability to invade the leaf, and show that growth form is as variable as for fully virulent isolates. We demonstrate that during certain interactions, Z. tritici isolates rarely invade the leaf and form pycnidia, but induce necrosis. These isolates are able to achieve higher epiphytic biomass than fully virulent isolates during asymptomatic growth, and may undergo very extensive asexual reproduction on the leaf surface. These findings have implications for open questions such as whether and how Z. tritici obtains nutrients on the leaf surface and the nature of its interaction with wheat defences.