香蕉(Musaspp。),在世界许多地方,主要的现金和主要水果作物,被枯萎病感染,这导致高达100%的产量损失,并造成社会后果。尖孢镰刀菌引起的巴拿马枯萎病的第1场和第2场。古巴(Foc)在世界范围内普遍存在,并严重影响许多传统品种。Foc热带种族4(FocTR4)的威胁在非洲各县迫在眉睫。然而,它在印度的发病率仅限于比哈尔邦(Katihar和Purnea),北方邦(Faizabad),中央邦(Burhanpur)和古吉拉特邦(Surat)。通过使用杀真菌剂管理Foc种族通常不是可持续的选择,因为疾病传播迅速,并且它们负面地改变了有益的外生植物和内生菌的生物多样性。此外,多菌灵/曲氟菌酯戊唑醇浸透的土壤也不能有效抑制香蕉的枯萎病。正在通过常规和高级育种方法来提高易感品种对枯萎病的抗性。然而,用Pisanglilly和YKM5等抗性基因型的细菌内生菌对香蕉内圈进行工程将诱导针对Foc的免疫反应,不管种族。不同香蕉品种中细菌内微生物组的组成主要是门变形杆菌,拟杆菌和放线菌。拮抗Foc的主要内生菌属为芽孢杆菌,短芽孢杆菌,拟芽孢杆菌,Virgibacillus,葡萄球菌,纤维单胞菌,微球菌,棒状杆菌,Kocuriaspp.,Paracocussp.,不动杆菌属。农杆菌,动脉瘤杆菌,肠杆菌,克雷伯菌属,溶血芽孢杆菌,微球菌,根瘤菌,芽孢杆菌,泛菌,假单胞菌,Serratia,微细菌,红球菌,窄食单胞菌,假黄单胞菌,Luteimonas,Dokdonella,红杆菌属,Luteibacter,类固醇,Nevskia,水痘,立克次体,军团菌,Tatlockia和链霉菌。这些内生细菌通过溶解磷酸盐促进香蕉幼苗的生长,生产吲哚乙酸和铁载体。在组织培养克隆的硬化阶段应用香蕉内生菌可作为对抗Foc的屏障。到目前为止,内生菌的MAMP分子,包括鞭毛蛋白,脂糖,肽聚糖,延伸率,冷休克蛋白和发夹诱导微生物相关分子模式(MAMP)触发的免疫以抑制植物病原体。通过MAPK和包括WRKY和MYC的转录因子诱导与ISR和SAR相关的事件级联。正在进行研究,以利用拮抗细菌内生菌对Foc分离株的潜力,并了解MAMP触发的免疫和代谢组学串扰调节抗性。这篇综述探讨了利用潜在的细菌内微生物群来对抗Foc的可能性,并开发具有细菌内生菌的纳米制剂,以提高对Foc感染香蕉的致命致病种族的功效。
背景:在线版本包含补充材料,可在10.1007/s13205-021-02833-5获得。
Banana (Musa spp.), a major cash and staple fruit crop in many parts of the world, is infected by Fusarium wilt, which contributes up to 100% yield loss and causes social consequences. Race 1 and race 2 of Panama wilt caused by Fusarium oxysporum f. sp. cubense (
Foc) are prevalent worldwide and seriously affect many traditional varieties. The threat of
Foc tropical race 4 (
Foc TR4) is looming large in African counties. However, its incidence in India has been confined to Bihar (Katihar and Purnea), Uttar Pradesh (Faizabad), Madhya Pradesh (Burhanpur) and Gujarat (Surat). Management of
Foc races by employing fungicides is often not a sustainable option as the disease spread is rapid and they negatively alter the biodiversity of beneficial ectophytes and endophytes. Besides, soil drenching with carbendazim/trifloxystrobin + tebuconazole is also not effective in suppressing the Fusarium wilt of banana. Improvement of resistance to Fusarium wilt in susceptible cultivars is being addressed through both conventional and advanced breeding approaches. However, engineering of banana endosphere with bacterial endophytes from resistant genotypes like Pisang lilly and YKM5 will induce the immune response against Foc, irrespective of races. The composition of the bacterial endomicrobiome in different banana cultivars is dominated by the phyla Proteobacteria, Bacteroidetes and Actinobacteria. The major bacterial endophytic genera antagonistic to
Foc are Bacillus, Brevibacillus, Paenibacillus, Virgibacillus, Staphylococcus, Cellulomonas, Micrococcus, Corynebacterium, Kocuria spp., Paracoccus sp., Acinetobacter spp. Agrobacterium, Aneurinibacillus, Enterobacter, Klebsiella, Lysinibacillus, Micrococcus, Rhizobium, Sporolactobacillus, Pantoea, Pseudomonas, Serratia, Microbacterium, Rhodococcus, Stenotrophomonas, Pseudoxanthomonas, Luteimonas, Dokdonella, Rhodanobacter, Luteibacter, Steroidobacter, Nevskia, Aquicella, Rickettsiella, Legionella, Tatlockia and Streptomyces. These bacterial endophytes promote the growth of banana plantlets by solubilising phosphate, producing indole acetic acid and siderophores. Application of banana endophytes during the hardening phase of tissue-cultured clones serves as a shield against Foc. Hitherto, MAMP molecules of endophytes including flagellin, liposaccharides, peptidoglycans, elongation factor, cold shock proteins and hairpins induce microbe-associated molecular pattern (MAMP)-triggered immunity to suppress plant pathogens. The cascade of events associated with ISR and SAR is induced through MAPK and transcription factors including WRKY and MYC. Studies are underway to exploit the potential of antagonistic bacterial endophytes against Foc isolates and to develop an understanding of the MAMP-triggered immunity and metabolomics cross talk modulating resistance. This review explores the possibility of harnessing the potential bacterial endomicrobiome against
Foc and developing nanoformulations with bacterial endophytes for increased efficacy against lethal pathogenic races of Foc infecting banana.
BACKGROUND: The online version contains supplementary material available at 10.1007/s13205-021-02833-5.