title: Identification and expression analysis of genes related to calyx persistence in Korla fragrant pear.
abstract: BACKGROUND
  The objective of this study was to increase understanding about genetic mechanisms affecting calyx persistence in Korla fragrant pear (Pyrus brestschneideri Rehd). Flowers were collected at early bloom, full bloom, and late bloom. The RNA was extracted from the flowers and then combined according to calyx type. Transcriptome and digital gene expression (DGE) profiles of flowers, ovaries, and sepals with persistent calyx (SC_hua, SC_ep, and SC_zf, respectively) were compared with those of flowers, ovaries, and sepals with deciduous calyx (TL_hua, TL_ep, and TL_zf, respectively). Temporal changes in the expression of selected genes in floral organs with either persistent or deciduous calyx were compared using real-time quantitative PCR (qRT-PCR).
  
  
  RESULTS
  Comparison of the transcriptome sequences for SC_hua and TL_hua indicated 26 differentially expressed genes (DEGs) with known relationship to abscission and 10 DEGs with unknown function. We identified 98 MYB and 21 SPL genes from the assembled unigenes. From SC_zf vs TL_zf, we identified 21 DEGs with known relationship to abscission and 18 DEGs with unknown function. From SC_ep vs TL_ep, 12 DEGs with known relationship to abscission were identified along with 11 DEGs with unknown function. Ten DEGs were identified by both transcriptome sequencing and DGE sequencing.
  
  
  CONCLUSIONS
  More than 50 DEGs were observed that were related to calyx persistence in Korla fragrant pear. Some of the genes were related to cell wall degradation, plant hormone signal transduction, and stress response. Other DEGs were identified as zinc finger protein genes and lipid transfer protein genes. Further analysis showed that calyx persistence in Korla fragment pear was a metabolic process regulated by many genes related to cell wall degradation and plant hormones.
authors.affiliation: Department of Horticulture, College of Agriculture, Shihezi University, Shihezi, 832003, Xinjiang, China. 1185248506@qq.com.|Xinjiang Production and Construction Corps Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization, Shihezi, 832003, Xinjiang, China. 1185248506@qq.com.
authors.forename: Maosong
authors.initials: M
authors.lastname: Pei
authors.affiliation: Department of Horticulture, College of Agriculture, Shihezi University, Shihezi, 832003, Xinjiang, China. njx105@163.com.|Xinjiang Production and Construction Corps Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization, Shihezi, 832003, Xinjiang, China. njx105@163.com.
authors.forename: Jianxin
authors.initials: J
authors.lastname: Niu
authors.affiliation: Department of Horticulture, College of Agriculture, Shihezi University, Shihezi, 832003, Xinjiang, China. 1429994796@qq.com.|Xinjiang Production and Construction Corps Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization, Shihezi, 832003, Xinjiang, China. 1429994796@qq.com.
authors.forename: Chenjing
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Horticulture, College of Agriculture, Shihezi University, Shihezi, 832003, Xinjiang, China. 528296410@qq.com.|Xinjiang Production and Construction Corps Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization, Shihezi, 832003, Xinjiang, China. 528296410@qq.com.
authors.forename: Fujun
authors.initials: F
authors.lastname: Cao
authors.affiliation: Department of Horticulture, College of Agriculture, Shihezi University, Shihezi, 832003, Xinjiang, China. 731982806@qq.com.|Xinjiang Production and Construction Corps Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization, Shihezi, 832003, Xinjiang, China. 731982806@qq.com.
authors.forename: Shaowen
authors.initials: S
authors.lastname: Quan
mesh_terms: D035264:Flowers / Q000235:genetics* / Q000254:growth & development; D017343:Genes, Plant; D058977:Molecular Sequence Annotation; D031989:Pyrus / Q000235:genetics* / Q000254:growth & development; D018749:RNA, Plant / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D059467:Transcriptome
chemical_list: D018749:RNA, Plant