title: Global gene expression profiling of two switchgrass cultivars following inoculation with Burkholderia phytofirmans strain PsJN.
abstract: Improvement and year-to-year stabilization of biomass yields are primary objectives for the development of a low-input switchgrass feedstock production system using microbial endophytes. An earlier investigation of the effect of Burkholderia phytofirmans strain PsJN on switchgrass germplasm demonstrated differential responses between genotypes. PsJN inoculation of cv. Alamo (lowland ecotype) increased the plant root system, shoot length, and biomass yields, whereas it had no beneficial effect on cv. Cave-in-Rock (upland ecotype). To understand the gene networks governing plant growth promotion responses triggered by PsJN, the gene expression profiles were analysed in these two hosts, following seedling inoculation. The Affymetrix platform switchgrass expressed sequence tag (EST) microarray chip representing 122 972 probe sets, developed by the DOE BioEnergy Science Center, was employed to assess transcript abundance at 0.5, 2, 4, and 8 DAI (days after PsJN inoculation). Approximately 20 000 switchgrass probe sets showed significant responses in either cultivar. Switchgrass identifiers were used to map 19 421 genes in MapMan software. There were apparent differences in gene expression profiling between responsive and non-responsive cultivars after PsJN inoculation. Overall, there were 14 984 and 9691 genes affected by PsJN inoculation in Alamo and Cave-in-Rock, respectively. Of these, 394 are annotated as pathogenesis-related genes. In the responsive cv. Alamo, 68 pathogenesis-related genes were affected, compared with only 10 in the non-responsive cv. Cave-in-Rock. At the very early stage at 0.5 DAI, both cultivars exhibited similar recognition and defence responses, such as genes in signalling and proteolysis, after which the defence reaction in the responsive cv. Alamo became weaker while it was sustained in non-responsive cv. Cave-in-Rock.
authors: Institute for Sustainable and Renewable Resources, Institute for Advanced Learning and Research, Danville, VA 24540, USA.
authors: Alejandra
authors: A
authors: Lara-Chavez
authors: Institute for Sustainable and Renewable Resources, Institute for Advanced Learning and Research, Danville, VA 24540, USA Department of Horticulture, Virginia Polytechnic Institute and State University, Blacksburg, VA 24601, USA.
authors: Scott
authors: S
authors: Lowman
authors: Institute for Sustainable and Renewable Resources, Institute for Advanced Learning and Research, Danville, VA 24540, USA.
authors: Seonhwa
authors: S
authors: Kim
authors: Plant Biology Division, the Samuel Roberts Noble Foundation, Inc., Ardmore, OK 73401, USA BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831, USA.
authors: Yuhong
authors: Y
authors: Tang
authors: Plant Biology Division, the Samuel Roberts Noble Foundation, Inc., Ardmore, OK 73401, USA BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831, USA.
authors: Jiyi
authors: J
authors: Zhang
authors: Plant Biology Division, the Samuel Roberts Noble Foundation, Inc., Ardmore, OK 73401, USA BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831, USA.
authors: Michael
authors: M
authors: Udvardi
authors: Department of Horticulture, Virginia Polytechnic Institute and State University, Blacksburg, VA 24601, USA.
authors: Jerzy
authors: J
authors: Nowak
authors: Institute for Sustainable and Renewable Resources, Institute for Advanced Learning and Research, Danville, VA 24540, USA Department of Horticulture, Virginia Polytechnic Institute and State University, Blacksburg, VA 24601, USA Department of Forest Resources and Environmental Conservation, Virginia Polytechnic Institute and State University, Blacksburg, VA 24601, USA.
authors: Barry
authors: B
authors: Flinn
authors: Institute for Sustainable and Renewable Resources, Institute for Advanced Learning and Research, Danville, VA 24540, USA Department of Horticulture, Virginia Polytechnic Institute and State University, Blacksburg, VA 24601, USA Department of Forest Resources and Environmental Conservation, Virginia Polytechnic Institute and State University, Blacksburg, VA 24601, USA chuansheng.mei@ialr.org.
authors: Chuansheng
authors: C
authors: Mei
mesh_terms: D019117:Burkholderia / Q000502:physiology*; D020869:Gene Expression Profiling; D006109:Poaceae / Q000235:genetics* / Q000382:microbiology
keywords: Beneficial bacterial endophyte; Burkholderia phytofirmans strain PsJN; Panicum virgatum L.; gene expression profiling; genotypic specificity; growth promotion