title: Transcriptome analysis reveals common and distinct mechanisms for sheepgrass (Leymus chinensis) responses to defoliation compared to mechanical wounding.
abstract: BACKGROUND
  Herbivore grazing is a multiple-component process that includes wounding, defoliation, and saliva deposition. Despite the extensive published research on mechanical wounding and defoliation, no analysis to identify the genes that specify defoliation and mechanical wounding has been performed. Moreover, the influence of the expression of these genes on plant regrowth after defoliation remains poorly understood.
  
  
  RESULTS
  Seven cDNA libraries for RNA samples collected from stubble tissues that had been mechanically wounded or defoliated at 2, 6 and 24 h along with the control were sequenced using the Illumina/Solexa platform. A comparative transcriptomic analysis of the sequencing data was conducted. In total, 1,836 and 3,238 genes were detected with significant differential expression levels after wounding and defoliation, respectively, during one day. GO, KOG and pathway-based enrichment analyses were performed to determine and further understand the biological functions of those differentially expressed genes (DEGs). The results demonstrated that both wounding and defoliation activated the systemic synthesis of jasmonate (JA). However, defoliation specifically reduced the expression levels of ribosomal protein genes, cell division or cell expansion-related genes, and lignin biosynthesis genes and may have negatively affected plant growth. Further analysis revealed that the regrowth of elongating leaves was significantly retarded after defoliation at 6 h through the following 7 days of measurement, suggesting that the gene expression pattern and phenotype are consistent. Fifteen genes were selected, and their expression levels were confirmed by quantitative RT-PCR (qRT-PCR). Thirteen of them exhibited expression patterns consistent with the digital gene expression (DGE) data.
  
  
  CONCLUSIONS
  These sequencing datasets allowed us to elucidate the common and distinct mechanisms of plant responses to defoliation and wounding. Additionally, the distinct DEGs represent a valuable resource for novel gene discovery that may improve plant resistance to defoliation from various processes.
authors.affiliation: Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing, P. R. China.
authors.forename: Shuangyan
authors.initials: S
authors.lastname: Chen
authors.affiliation: Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing, P. R. China ; Graduate Schoo1 of the Chinese Academy of Sciences, Beijing, P. R. China.
authors.forename: Yueyue
authors.initials: Y
authors.lastname: Cai
authors.affiliation: Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing, P. R. China ; Entry-Exit Inspection and Quarantine Bureau, Heze, Shandong, P.R. China.
authors.forename: Lexin
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing, P. R. China ; Graduate Schoo1 of the Chinese Academy of Sciences, Beijing, P. R. China.
authors.forename: Xueqing
authors.initials: X
authors.lastname: Yan
authors.affiliation: Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing, P. R. China.
authors.forename: Liqin
authors.initials: L
authors.lastname: Cheng
authors.affiliation: Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing, P. R. China.
authors.forename: Dongmei
authors.initials: D
authors.lastname: Qi
authors.affiliation: Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing, P. R. China.
authors.forename: Qingyuan
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing, P. R. China.
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Li
authors.affiliation: Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing, P. R. China.
authors.forename: Gongshe
authors.initials: G
authors.lastname: Liu
mesh_terms: D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D063990:Gene Ontology; D017343:Genes, Plant; D060434:Herbivory; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D006109:Poaceae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D059467:Transcriptome
chemical_list: D010940:Plant Proteins