Tör Mahmut, Wood Tom, Webb Anne, Göl Deniz, McDowell John M
Department of Biology, School of Science and the Environment, University of Worcester, Henwick Grove, Worcester WR2 6AJ, UK.
NIAB, Cambridge CB3 0LE, UK.
Semin Cell Dev Biol. 2023 Oct-Nov;148-149:42-50. doi: 10.1016/j.semcdb.2023.01.010. Epub 2023 Jan 18.
Downy mildews are obligate oomycete pathogens that attack a wide range of plants and can cause significant economic impacts on commercial crops and ornamental plants. Traditionally, downy mildew disease control relied on an integrated strategies, that incorporate cultural practices, deployment of resistant cultivars, crop rotation, application of contact and systemic pesticides, and biopesticides. Recent advances in genomics provided data that significantly advanced understanding of downy mildew evolution, taxonomy and classification. In addition, downy mildew genomics also revealed that these obligate oomycetes have reduced numbers of virulence factor genes in comparison to hemibiotrophic and necrotrophic oomycetes. However, downy mildews do deploy significant arrays of virulence proteins, including so-called RXLR proteins that promote virulence or are recognized as avirulence factors. Pathogenomics are being applied to downy mildew population studies to determine the genetic diversity within the downy mildew populations and manage disease by selection of appropriate varieties and management strategies. Genome editing technologies have been used to manipulate host disease susceptibility genes in different plants including grapevine and sweet basil and thereby provide new soucres of resistance genes against downy mildews. Previously, it has proved difficult to transform and manipulate downy mildews because of their obligate lifestyle. However, recent exploitation of RNA interference machinery through Host-Induced Gene Silencing (HIGS) and Spray-Induced Gene Silencing (SIGS) indicate that functional genomics in downy mildews is now possible. Altogether, these breakthrough technologies and attendant fundamental understanding will advance our ability to mitigate downy mildew diseases.
霜霉病是专性卵菌病原体，可侵袭多种植物，会对经济作物和观赏植物造成重大经济影响。传统上，霜霉病的防治依赖于综合策略，包括栽培措施、种植抗病品种、轮作、使用触杀性和内吸性农药以及生物农药。基因组学的最新进展提供了数据，极大地推动了对霜霉病进化、分类学和分类的理解。此外，霜霉病基因组学还表明，与半活体营养型和坏死营养型卵菌相比，这些专性卵菌的毒力因子基因数量有所减少。然而，霜霉病确实会部署大量的毒力蛋白，包括所谓的促进毒力或被视为无毒因子的RXLR蛋白。病原基因组学正被应用于霜霉病种群研究，以确定霜霉病种群内的遗传多样性，并通过选择合适的品种和管理策略来控制病害。基因组编辑技术已被用于操纵包括葡萄和甜罗勒在内的不同植物中的宿主感病基因，并由此提供了抗霜霉病的新抗性基因来源。以前，由于霜霉病的专性生活方式，很难对其进行转化和操纵。然而，最近通过宿主诱导基因沉默（HIGS）和喷雾诱导基因沉默（SIGS）对RNA干扰机制的利用表明，现在对霜霉病进行功能基因组学研究是可行的。总之，这些突破性技术以及随之而来的基本认识将提高我们减轻霜霉病病害的能力。
