title: The ABA effect on the accumulation of an invertase inhibitor transcript that is driven by the CAMV35S promoter in ARABIDOPSIS.
abstract: Invertase (beta-D-fructofuranosidase; EC 3.2.1.26) catalyzes the conversion of sucrose into glucose and fructose and is involved in an array of important processes, including phloem unloading, carbon partitioning, the response to pathogens, and the control of cell differentiation and development. Its importance may have caused the invertases to evolve into a multigene family whose members are regulated by a variety of different mechanisms, such as pH, sucrose levels, and inhibitor proteins. Although putative invertase inhibitors in the Arabidopsis genome are easy to locate, few studies have been conducted to elucidate their individual functions in vivo in plant growth and development because of their high redundancy. In this study we assessed the functional role of the putative invertase inhibitors in Arabidopsis by generating transgenic plants harboring a putative invertase inhibitor gene under the control of the CaMV35S promoter. A transgenic plant that expressed high levels of the putative invertase inhibitor transcript when grown under normal conditions was chosen for the current study. To our surprise, the stability of the invertase inhibitor transcripts was shown to be down-regulated by the phytohormone ABA (abscisic acid). It is well established that ABA enhances invertase activity in vivo but the underlying mechanisms are still poorly understood. Our results thus suggest that one way ABA regulates invertase activity is by down-regulating its inhibitor.
authors.affiliation: College of Life Sciences and Biotechnology, Korea University, Seoul 136-713, Korea.
authors.forename: Eun-Ji
authors.initials: EJ
authors.lastname: Koh
authors.forename: Sung June
authors.initials: SJ
authors.lastname: Lee
authors.forename: Suk-Whan
authors.initials: SW
authors.lastname: Hong
authors.forename: Hoi Seon
authors.initials: HS
authors.lastname: Lee
authors.forename: Hojoung
authors.initials: H
authors.lastname: Lee
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D003513:Cycloheximide / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D010937:Plant Growth Regulators / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D011500:Protein Synthesis Inhibitors / Q000378:metabolism; D020871:RNA Stability; D016415:Sequence Alignment; D043324:beta-Fructofuranosidase / Q000037:antagonists & inhibitors* / Q000235:genetics* / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D010937:Plant Growth Regulators; D011500:Protein Synthesis Inhibitors; D002734:Chlorophyll; D000040:Abscisic Acid; D003513:Cycloheximide; D043324:beta-Fructofuranosidase