RNAseq Transcriptional Profiling following Whip Development in Sugarcane Smut Disease

PLoS One. 2016 Sep 1;11(9):e0162237. doi: 10.1371/journal.pone.0162237. eCollection 2016.

Abstract

Sugarcane smut disease is caused by the biotrophic fungus Sporisorium scitamineum. The disease is characterized by the development of a whip-like structure from the primary meristems, where billions of teliospores are produced. Sugarcane smut also causes tillering and low sucrose and high fiber contents, reducing cane productivity. We investigated the biological events contributing to disease symptoms in a smut intermediate-resistant sugarcane genotype by examining the transcriptional profiles (RNAseq) shortly after inoculating the plants and immediately after whip emission. The overall picture of disease progression suggests that premature transcriptional reprogramming of the shoot meristem functions continues until the emergence of the whip. The guidance of this altered pattern is potentially primarily related to auxin mobilization in addition to the involvement of other hormonal imbalances. The consequences associated with whip emission are the modulation of typical meristematic functions toward reproductive organ differentiation, requiring strong changes in carbon partitioning and energy production. These changes include the overexpression of genes coding for invertases and trehalose-6P synthase, as well as other enzymes from key metabolic pathways, such as from lignin biosynthesis. This is the first report describing changes in the transcriptional profiles following whip development, providing a hypothetical model and candidate genes to further study sugarcane smut disease progression.

MeSH terms

  • Gene Expression Profiling*
  • Plant Diseases / microbiology*
  • Saccharum / genetics
  • Saccharum / microbiology*
  • Sequence Analysis, RNA / methods*
  • Transcription, Genetic*
  • Ustilaginales / pathogenicity*

Grants and funding

The authors acknowledge the support of the Brazilian institution FAPESP (grant numbers 2010/05591-9; 2015/07112-4 [C.B.M.-V.] and fellowships to A.C.P. (2012/09524-0); P.D.C.S (2013/25599-2); L.M.T (2014/17034-8); L.P.P (2013/15014-7). We thank the sequencing facility Center of Functional Genomics (USP, Campus “Luiz de Queiroz”); NAP/MEPA (Núcleo de Apoio à Pesquisa em Microscopia Eletrônica Aplicada a Agricultura) and Laboratórios de Genética Molecular, Departamento de Fitopatologia e Nematologia, and Plantas Hortículas, Departamento de Produção Vegetal, ESALQ. Mendelics Analise Genômica provided support in the form of a salary for author JPK, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of JPK are articulated in the 'author contributions' section.