title: Transcriptome phase distribution analysis reveals diurnal regulated biological processes and key pathways in rice flag leaves and seedling leaves.
abstract: Plant diurnal oscillation is a 24-hour period based variation. The correlation between diurnal genes and biological pathways was widely revealed by microarray analysis in different species. Rice (Oryza sativa) is the major food staple for about half of the world's population. The rice flag leaf is essential in providing photosynthates to the grain filling. However, there is still no comprehensive view about the diurnal transcriptome for rice leaves. In this study, we applied rice microarray to monitor the rhythmically expressed genes in rice seedling and flag leaves. We developed a new computational analysis approach and identified 6,266 (10.96%) diurnal probe sets in seedling leaves, 13,773 (24.08%) diurnal probe sets in flag leaves. About 65% of overall transcription factors were identified as flag leaf preferred. In seedling leaves, the peak of phase distribution was from 2:00am to 4:00am, whereas in flag leaves, the peak was from 8:00pm to 2:00am. The diurnal phase distribution analysis of gene ontology (GO) and cis-element enrichment indicated that, some important processes were waken by the light, such as photosynthesis and abiotic stimulus, while some genes related to the nuclear and ribosome involved processes were active mostly during the switch time of light to dark. The starch and sucrose metabolism pathway genes also showed diurnal phase. We conducted comparison analysis between Arabidopsis and rice leaf transcriptome throughout the diurnal cycle. In summary, our analysis approach is feasible for relatively unbiased identification of diurnal transcripts, efficiently detecting some special periodic patterns with non-sinusoidal periodic patterns. Compared to the rice flag leaves, the gene transcription levels of seedling leaves were relatively limited to the diurnal rhythm. Our comprehensive microarray analysis of seedling and flag leaves of rice provided an overview of the rice diurnal transcriptome and indicated some diurnal regulated biological processes and key functional pathways in rice.
authors.affiliation: Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences and National Centre for Plant Gene Research, Beijing, China.
authors.forename: Wenying
authors.initials: W
authors.lastname: Xu
authors.forename: Rendong
authors.initials: R
authors.lastname: Yang
authors.forename: Meina
authors.initials: M
authors.lastname: Li
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Xing
authors.forename: Wenqiang
authors.initials: W
authors.lastname: Yang
authors.forename: Guang
authors.initials: G
authors.lastname: Chen
authors.forename: Han
authors.initials: H
authors.lastname: Guo
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Gong
authors.forename: Zhou
authors.initials: Z
authors.lastname: Du
authors.forename: Zhenhai
authors.initials: Z
authors.lastname: Zhang
authors.forename: Xingming
authors.initials: X
authors.lastname: Hu
authors.forename: Dong
authors.initials: D
authors.lastname: Wang
authors.forename: Qian
authors.initials: Q
authors.lastname: Qian
authors.forename: Tai
authors.initials: T
authors.lastname: Wang
authors.forename: Zhen
authors.initials: Z
authors.lastname: Su
authors.forename: Yongbiao
authors.initials: Y
authors.lastname: Xue
mesh_terms: D000465:Algorithms; D017360:Arabidopsis / Q000235:genetics; D001483:Base Sequence; D001686:Biological Phenomena / Q000235:genetics*; D002940:Circadian Rhythm / Q000235:genetics*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D012275:Oryza / Q000235:genetics*; D018515:Plant Leaves / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D036226:Seedlings / Q000235:genetics*; D015398:Signal Transduction / Q000235:genetics*; D013213:Starch / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics
chemical_list: D014157:Transcription Factors; D013395:Sucrose; D013213:Starch