Integration of early disease-resistance phenotyping, histological characterization, and transcriptome sequencing reveals insights into downy mildew resistance in impatiens  

作　　者：Ze Peng Yanhong He Saroj Parajuli Qian You Weining Wang Krishna Bhattarai Aaron JPalmateer Zhanao Deng 

机构地区：[1]University of Florida,IFAS,Department of Environmental Horticulture,Gulf Coast Research and Education Center,14625 County Road 672,Wimauma,FL 33598,USA [2]State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources,South China Agricultural University,510642 Guangzhou,China [3]Visiting scholar at University of Florida,IFAS,Department of Environmental Horticulture,Gulf Coast Research and Education Center,14625 County Road 672,Wimauma,FL 33598,USA [4]Key Laboratory of Horticultural Plant Biology,Ministry of Education,College of Horticulture and Forestry Sciences,Huazhong Agricultural University,430070 Wuhan,Hubei,China [5]University of Florida,IFAS,Department of Plant Pathology,Tropical Research and Education Center,18905 S.W.280th Street,Homestead,FL 33031,USA [6]Present address:Bayer Environmental Science US,5000 Centregreen Way,Cary,NC 27513,USA

出　　处：《Horticulture Research》2021年第1期1473-1494,共22页园艺研究（英文）

基　　金：supported by grants from the Florida Department of Agriculture and Consumer Service(FDACS)Florida Specialty Crop Block Grant Program(FDACS contract#020705 to A.P.and Z.D.);the Fred C.Gloeckner Foundation,Inc.(Z.D.),and the USDA/NIFA hatch projects(Project#FLA-GCR-005065 and FLA-GCC-005507)(Z.D.)。

摘　　要：Downy mildew(DM),caused by obligate parasitic oomycetes,is a destructive disease for a wide range of crops worldwide.Recent outbreaks of impatiens downy mildew(IDM)in many countries have caused huge economic losses.A system to reveal plant–pathogen interactions in the early stage of infection and quickly assess resistance/susceptibility of plants to DM is desired.In this study,we established an early and rapid system to achieve these goals using impatiens as a model.Thirty-two cultivars of Impatiens walleriana and I.hawkeri were evaluated for their responses to IDM at cotyledon,first/second pair of true leaf,and mature plant stages.All I.walleriana cultivars were highly susceptible to IDM.While all I.hawkeri cultivars were resistant to IDM starting at the first true leaf stage,many(14/16)were susceptible to IDM at the cotyledon stage.Two cultivars showed resistance even at the cotyledon stage.Histological characterization showed that the resistance mechanism of the I.hawkeri cultivars resembles that in grapevine and type II resistance in sunflower.By integrating full-length transcriptome sequencing(Iso-Seq)and RNA-Seq,we constructed the first reference transcriptome for Impatiens comprised of 48,758 sequences with an N50 length of 2060 bp.Comparative transcriptome and qRT-PCR analyses revealed strong candidate genes for IDM resistance,including three resistance genes orthologous to the sunflower gene RGC203,a potential candidate associated with DM resistance.Our approach of integrating early disease-resistance phenotyping,histological characterization,and transcriptome analysis lay a solid foundation to improve DM resistance in impatiens and may provide a model for other crops.

关 键 词：CULTIVAR MILDEW CROPS 

分 类 号：S436.8[农业科学—农业昆虫与害虫防治]