Homologues of key circadian clock genes present in Verticillium dahliae do not direct circadian programs of development or mRNA abundance
Homologues of key circadian clock genes present in Verticillium dahliae do not direct circadian programs of development or mRNA abundance
复制标题
大丽黄萎病中存在的关键生物钟基因的同源物并不指导发育或 mRNA 丰度的昼夜节律程序
DOI：
10.1101/2019.12.20.883116
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Cascant-Lopez E
中科院分区：
文献类型：
--
作者：
Cascant-Lopez E
许多生物体内都有生物钟，以促进它们适应有节奏的环境。虽然通过真菌模型粗神经孢子虫（neurospora crassa）对生物钟的分子机制有了广泛的了解，但对其他真菌的生物钟知之甚少。与许多重要的植物病原体，包括维管枯萎真菌大丽花黄萎病属同一类。我们发现了n的同源物。大丽花属植物，在关键蛋白结构域上具有高度保守性。然而，没有证据表明在分生孢子和微核的日常形成中存在内源性的、自由运行的和可携带的节律。客栈。crassthefrequency （frq）基因编码一种中央时钟蛋白，该蛋白有节奏地表达，并对光线做出反应。相反，vdfrq的表达不受光调节。在恒定的黑暗和温度下，48小时的时间基因表达谱显示关键时钟基因没有昼夜节律表达。此外，在24小时的时间过程中，RNA测序显示在恒定的黑暗中没有强劲的RNA振荡。野生型v基因表达比较。dahliae和aΔVdfrqmutant表明，在缺乏vdfrq的情况下，参与代谢、运输和氧化还原过程的基因被错误调控。此外，VdΔfrqmutants以菌株依赖的方式表现出生长缺陷和致病性降低。我们的数据表明，如果黄萎病菌中存在生物钟，那么它是基于其他机制，如VdFRQ和WC蛋白的转录后相互作用或FRQ-less振荡器的组成部分。另一种可能是，虽然时钟蛋白的原始功能得到了维持，但在这个物种中，产生节律性的相互作用已经丢失，或者只有在满足特定环境条件时才被触发。基因组中保守时钟基因的存在不应被视为昼夜节律功能的决定性证据。生物使用生物钟来协调细胞过程的活动，使它们在一天中的最佳时间发生。对丝状真菌神经孢子菌（neurospora crassassa）进行的研究揭示了其生物钟组成、与环境的相互作用以及如何驱动细胞生物化学和生理的大量信息。虽然神经孢子菌时钟基因的同源物存在于许多真菌中，但功能性时钟仅在少数真菌中得到证实。重要的是，最近报道了植物病原体葡萄孢菌的生物钟与毒力之间的联系。我们报道了另一种重要的植物病原体，大丽花黄萎病，包含所有关键时钟基因的同源物。我们发现分生孢子和微核的昼夜发育不受生物钟的影响。此外，在恒定的环境中，我们没有发现有节奏的转录积累的证据。然而，中央时钟成分的缺失导致生长改变和毒性降低。这让我们质疑时钟基因在黄萎病中的作用。我们不得不认为，在这个物种中，产生节律性的相互作用已经丢失，纯粹是通过时钟蛋白的转录后修饰产生的，只有在满足特定环境条件时才会触发，或者从未进化过。
Many organisms harbour circadian clocks that promote their adaptation to the rhythmic environment. While a broad knowledge of the molecular mechanism of circadian clocks has been gained through the fungal modelNeurospora crassa, little is known about circadian clocks in other fungi.N. crassabelongs to the same class as many important plant pathogens including the vascular wilt fungusVerticillium dahliae.We identified homologues ofN. crassaclock proteins inV. dahliae,which showed high conservation in key protein domains. However, no evidence for an endogenous, free-running and entrainable rhythm was observed in the daily formation of conidia and microsclerotia. InN. crassathefrequency(frq) gene encodes a central clock protein expressed rhythmically and in response to light. In contrast, expression ofVdfrqis not light-regulated. Temporal gene expression profiling over 48 hours in constant darkness and temperature revealed no circadian expression of key clock genes. Furthermore, RNA-seq over a 24 h time-course revealed no robust oscillations of RNA in constant darkness. Comparison of gene expression between wild-typeV. dahliaeand aΔVdfrqmutant showed that genes involved in metabolism, transport and redox processes are mis-regulated in the absence ofVdfrq. In addition,VdΔfrqmutants display growth defects and reduced pathogenicity in a strain dependent manner. Our data indicate that if a circadian clock exists in Verticillium, it is based on alternative mechanisms such as post-transcriptional interactions of VdFRQ and the WC proteins or the components of a FRQ-less oscillator. Alternatively, it could be that whilst the original functions of the clock proteins have been maintained, in this species the interactions that generate rhythmicity have been lost or are only triggered when specific environmental conditions are met. The presence of conserved clock genes in genomes should not be taken as definitive evidence of circadian function.Author summaryCircadian clocks are used by organisms to orchestrate the activity of cellular processes such that they occur at an optimal time of day. Research carried out in the filamentous fungusNeurospora crassahas revealed a huge amount of information about the components its circadian clock, its interactions with the environment and how it drives cellular biochemistry and physiology. Although homologues of the Neurospora clock genes are present in a number of fungi, functional clocks have been demonstrated in a just a handful. Importantly, a link between the circadian clock of the plant pathogenBotrytis cinereaand virulence has recently been reported. We report that another significant plant pathogen,Verticillium dahliae,contains well-conserved homologues of all key clock genes. We find that diurnal development of conidia and microsclerotia is not influenced by a circadian clock. Furthermore, in a constant environment we find no evidence of rhythmic transcript accumulation. However, deletion of the central clock component results in altered growth and reduced virulence. This led us to question the role of clock genes in Verticillium. We are forced to consider that in this species the interactions that generate rhythmicity have been lost, are generated purely via post-transcriptional modification of clock proteins, are only triggered when specific environmental conditions are met or never evolved.
登录
查看更多内容
一种有助于鉴定黄萎病和大丽花的培养基
影响因子：
2.7
作者：
P. Talboys
通讯作者：
P. Talboys
设定节奏。
DOI：
10.7748/en.10.2.5.s10
发表时间：
2002
期刊：
Emergency nurse : the journal of the RCN Accident and Emergency Nursing Association
影响因子：
--
作者：
N. Lipley
通讯作者：
N. Lipley
针叶树耐霜性的分子生物学及其在树木育种中的潜在应用
影响因子：
7.4
作者：
D. Clapham;I. Ekberg;C. H. Anthony Little;O. Savolainen
通讯作者：
O. Savolainen
影响因子：
11.3
作者：
Baker CL;Loros JJ;Dunlap JC
通讯作者：
Dunlap JC
影响因子：
56.9
作者：
Crosthwaite, SK;Dunlap, JC;Loros, JJ
通讯作者：
Loros, JJ