title: Transcriptomic adaptations in rice suspension cells under sucrose starvation.
abstract: Sugar is an important resource for energy generation and developmental regulation in plants, and sucrose starvation causes enormous changes in cellular morphology, enzyme activities and gene expression. Genome-wide gene expression profiling provides a comprehensive knowledge of gene expression under nutrient depletion and senescence; however, that of a monocot model plant, rice, under sucrose depletion is still under investigation. Here, the time-course monitoring of gene expression profiles in sucrose-starved rice (Oryza sativa cv Tainung67) suspension cells was investigated by 21495 probes contained in Agilent rice chip. In sucrose-starved cells, the induced vacuolar biogenesis coincided with significantly upregulated transcripts of H+-pyrophosphatase, delta-TIP, one putative alpha-TIP, several vacuolar proteases and proteinase inhibitors, and one OsATG3. To survey the overall metabolic adaptations under sucrose depletion, the genes with significantly altered expression level were incorporated into multiple metabolic pathways. Most genes encoding enzymes involved in biosynthesis and degradation pathways of various macromolecules were comprehensively down-and upregulated, respectively, with sucrose starvation. Transcriptional regulation of gene expression is important for physiological adaptations to environmental stress, and many transcription factors, including bZIPs, NACs, and WRKY, showed significant increase in transcriptional level under sucrose starvation. Concurrently, statistical analysis revealed that their corresponding consensus cis-elements, such as ABA-responsive element, CACG, ACI, ACII and CTTATCC, were frequently found in the promoter regions of many sucrose starvation-upregulated genes. Particle bombardment-mediated and luciferase activity-based transient promoter assays revealed the CTTATCC, derived form TATCCA, and the AC motifs to be promising sucrose-starvation responsive activators in rice suspension cells.
authors.affiliation: Institute of Life Science, National Defense Medical Center, Taipei, Taiwan, ROC.
authors.forename: Huei-Jing
authors.initials: HJ
authors.lastname: Wang
authors.forename: Ai-Ru
authors.initials: AR
authors.lastname: Wan
authors.forename: Chia-Mei
authors.initials: CM
authors.lastname: Hsu
authors.forename: Kuo-Wei
authors.initials: KW
authors.lastname: Lee
authors.forename: Su-May
authors.initials: SM
authors.lastname: Yu
authors.forename: Guang-Yuh
authors.initials: GY
authors.lastname: Jauh
mesh_terms: D001483:Base Sequence; D018929:Cell Culture Techniques / Q000379:methods; D004734:Energy Metabolism; D005943:Gluconeogenesis; D008954:Models, Biological; D012275:Oryza / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013395:Sucrose / Q000494:pharmacology*; D014158:Transcription, Genetic; D014617:Vacuoles / Q000201:enzymology
chemical_list: D011994:Recombinant Proteins; D013395:Sucrose; D010447:Peptide Hydrolases