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Author Hayama, Ryosuke ♦ Agashe, Bhavna ♦ Luley, Elisabeth ♦ King, Rod ♦ Coupland, George
Source World Health Organization (WHO)-Global Index Medicus
Content type Text
Publisher American Society of Plant Biologists
File Format HTM / HTML
Language English
Difficulty Level Medium
Subject Domain (in DDC) Computer science, information & general works ♦ Library & information sciences ♦ Natural sciences & mathematics ♦ Chemistry & allied sciences ♦ Life sciences; biology ♦ Physiology & related subjects ♦ Biochemistry ♦ Genetics and evolution ♦ Natural history of organisms ♦ Technology ♦ Medicine & health ♦ Human anatomy, cytology, histology ♦ Human physiology ♦ Pharmacology and therapeutics ♦ Diseases ♦ Manufacture for specific uses ♦ Precision instruments & other devices
Subject Domain (in MeSH) Plant Structures ♦ Anatomy ♦ Eukaryota ♦ Organisms ♦ Amino Acids, Peptides, and Proteins ♦ Chemicals and Drugs ♦ Investigative Techniques ♦ Analytical, Diagnostic and Therapeutic Techniques and Equipment ♦ Physical Phenomena ♦ Genetic Phenomena ♦ Physiological Phenomena ♦ Biological Sciences ♦ Information Science ♦ Information Science
Subject Keyword Discipline Botany ♦ Circadian Rhythm ♦ Physiology ♦ Flowers ♦ Genetics ♦ Gene Expression Regulation, Plant ♦ Radiation Effects ♦ Ipomoea ♦ Photoperiod ♦ Plant Proteins ♦ Arabidopsis Proteins ♦ Classification ♦ Darkness ♦ Light ♦ Molecular Sequence Data ♦ Phylogeny ♦ Protein Isoforms ♦ Reverse Transcriptase Polymerase Chain Reaction ♦ Journal Article
Abstract Seasonal control of flowering through responsiveness to daylength shows extreme variation. Different species flower in response to long days or short days (SDs), and this difference evolved several times. The molecular mechanisms conferring these responses have been compared in detail only in Arabidopsis thaliana and rice (Oryza sativa) and suggest that a conserved pathway confers daylength responses through regulation of FLOWERING LOCUS T (FT) transcription by CONSTANS (CO). We studied Pharbitis (Ipomoea nil; formerly, Pharbitis nil), a widely used SD model species and a member of the Convolvulaceae, and showed using transgenic plants together with detailed expression analysis that two putative orthologs of FT (Pn FT1 and Pn FT2) promote flowering specifically under SDs. These genes are expressed only under SDs, and light flashes given during the night reduce their expression and prevent flowering. We demonstrate that in Pharbitis a circadian rhythm set by the light-to-dark transition at dusk regulates Pn FT expression, which rises only when the night is longer than 11 h. Furthermore, Pharbitis accessions that differ in their critical night-length responses express Pn FT at different times after dusk, demonstrating that natural genetic variation influencing the clock regulating Pn FT expression alters the flowering response. In these assays, Pn FT mRNA abundance was not related to Pn CO expression, suggesting that Pn FT may be regulated by a different transcription factor in Pharbitis. We conclude that SD response in Pharbitis is controlled by a dedicated light sensitive clock, set by dusk, that activates Pn FT transcription in darkness, a different mechanism for measuring daylength than described for Arabidopsis and rice.
Description Country affiliation: Germany
Author Affiliation: Hayama R ( Max Planck Institute for Plant Breeding Research, D-50829 Cologne, Germany.)
ISSN 10404651
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Reading ♦ Research ♦ Self Learning
Interactivity Type Expositive
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2007-10-01
Publisher Place United States
e-ISSN 1531298X
Volume Number 19
Issue Number 10

Source: WHO-Global Index Medicus