Members of the Fusarium oxysporum species complex include pathogenic and non-pathogenic isolates and infect a broad range of plant species. F. oxysporum f. sp. cubense (Foc) causes the destructive Fusarium wilt of banana, and the recently emerged Foc tropical race 4 strain threatens the global banana industry. Secreted in xylem (SIX) genes encode for F. oxysporum effector proteins that are associated with virulence in pathogenic F. oxysporum, however they have rarely been reported from non-pathogenic F. oxysporum isolates. Our recent survey of asymptomatic banana plants grown in Foc-infested fields in Queensland and northern NSW revealed that diverse Fusarium spp, including F. oxysporum, reside in the plant roots and pseudostem without causing obvious damage to the plant. Intriguingly, we amplified SIX genes from several of the putative endophytic F. oxysporum isolates identified in the survey and found that they differ in their profile to known Foc SIX genes. To study the role of the endophytic F. oxysporum isolates in planta and the biological function of their SIX genes in more detail, we will re-inoculate cultivated and wild diploid banana lines with the endophytic F. oxysporum strains under glasshouse conditions to assess if they are non-pathogenic on banana. Secondly, we will determine whether the endophytic F. oxysporum SIX genes are expressed in planta and/or in vitro and look at the transcriptome changes occurring in the host following infection. Finally, endophytic F. oxysporum strains transformed with GFP will be used to investigate the extent of fungal colonisation in the plant.
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机译：Fusarium oxysporum物种复合物的成员包括致病性和非致病性分离物，并感染广泛的植物物种。 F. oxysporum f。 sp。 Cumense（Foc）导致香蕉的破坏性枯萎病，最近出现的Foc热带比赛4菌株威胁着全球香蕉行业。在Xylem（六种）基因中分泌的用于编码与毒性F. oxysporum中的毒力相关的oxysporum效应蛋白，但是它们很少从非致病性f. oxysporum分离物中报道。我们最近对昆士兰州和北方北部Foc-infested领域生长的无症状香蕉植物的调查显示，多样化的镰刀SPP，包括F. Oxysporum，居住在植物根部和假索迪姆，而不会对植物造成明显损害。有趣的是，我们从调查中鉴定的若干推定的内生成的oxysporum分离物中扩增了六个基因，发现它们在其概况中与已知的FOC六个基因不同。为了研究Hearophytic F. oxysporum分离株的作用及其六种基因的生物学功能更详细，我们将在玻璃室条件下用内心F. oxysporum菌株重新接种栽培和野生二倍体香蕉线，以评估它们在香蕉上是非致病性的。其次，我们将判断内心F. oxysporum六种基因在植物和/或体外表达，并在感染后宿主中发生的转录组变化。最后，用GFP转化的内生孢子菌株将用于研究植物中真菌定植的程度。
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