title: Sorghum expressed sequence tags identify signature genes for drought, pathogenesis, and skotomorphogenesis from a milestone set of 16,801 unique transcripts.
abstract: Improved knowledge of the sorghum transcriptome will enhance basic understanding of how plants respond to stresses and serve as a source of genes of value to agriculture. Toward this goal, Sorghum bicolor L. Moench cDNA libraries were prepared from light- and dark-grown seedlings, drought-stressed plants, Colletotrichum-infected seedlings and plants, ovaries, embryos, and immature panicles. Other libraries were prepared with meristems from Sorghum propinquum (Kunth) Hitchc. that had been photoperiodically induced to flower, and with rhizomes from S. propinquum and johnsongrass (Sorghum halepense L. Pers.). A total of 117,682 expressed sequence tags (ESTs) were obtained representing both 3' and 5' sequences from about half that number of cDNA clones. A total of 16,801 unique transcripts, representing tentative UniScripts (TUs), were identified from 55,783 3' ESTs. Of these TUs, 9,032 are represented by two or more ESTs. Collectively, these libraries were predicted to contain a total of approximately 31,000 TUs. Individual libraries, however, were predicted to contain no more than about 6,000 to 9,000, with the exception of light-grown seedlings, which yielded an estimate of close to 13,000. In addition, each library exhibits about the same level of complexity with respect to both the number of TUs preferentially expressed in that library and the frequency with which two or more ESTs is found in only that library. These results indicate that the sorghum genome is expressed in highly selective fashion in the individual organs and in response to the environmental conditions surveyed here. Close to 2,000 differentially expressed TUs were identified among the cDNA libraries examined, of which 775 were differentially expressed at a confidence level of 98%. From these 775 TUs, signature genes were identified defining drought, Colletotrichum infection, skotomorphogenesis (etiolation), ovary, immature panicle, and embryo.
authors.affiliation: Department of Plant Biology, University of Georgia, Athens, 30602, USA. lpratt@plantbio.uga.edu
authors.forename: Lee H
authors.initials: LH
authors.lastname: Pratt
authors.forename: Chun
authors.initials: C
authors.lastname: Liang
authors.forename: Manish
authors.initials: M
authors.lastname: Shah
authors.forename: Feng
authors.initials: F
authors.lastname: Sun
authors.forename: Haiming
authors.initials: H
authors.lastname: Wang
authors.forename: St Patrick
authors.initials: SP
authors.lastname: Reid
authors.forename: Alan R
authors.initials: AR
authors.lastname: Gingle
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Paterson
authors.forename: Rod
authors.initials: R
authors.lastname: Wing
authors.forename: Ralph
authors.initials: R
authors.lastname: Dean
authors.forename: Robert
authors.initials: R
authors.lastname: Klein
authors.forename: Henry T
authors.initials: HT
authors.lastname: Nguyen
authors.forename: Hong-Mei
authors.initials: HM
authors.lastname: Ma
authors.forename: Xin
authors.initials: X
authors.lastname: Zhao
authors.forename: Daryl T
authors.initials: DT
authors.lastname: Morishige
authors.forename: John E
authors.initials: JE
authors.lastname: Mullet
authors.forename: Marie-Michèle
authors.initials: MM
authors.lastname: Cordonnier-Pratt
mesh_terms: D018076:DNA, Complementary / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D020224:Expressed Sequence Tags; D017343:Genes, Plant; D010935:Plant Diseases / Q000235:genetics; D045868:Sorghum / Q000235:genetics* / Q000254:growth & development; D014158:Transcription, Genetic
chemical_list: D018076:DNA, Complementary; D018744:DNA, Plant