Lin, Ter-yun , Shih, Ming-che .
Involvement of a novel phospholipase C in hypoxia signaling pathways in Arabidopsis.
Exposure to low oxygen (hypoxia) is a stress commonly encountered by both plants and animals. To survive prolonged periods of hypoxia, all aerobic organisms have had to evolve mechanisms for sensing oxygen availability and to adjust their cellular metabolism accordingly. One major response in plant cells under hypoxia is the switching from aerobic respiration to fermentation, which requires the induction of alcohol dehydrogenase (ADH) gene. We previously isolated Arabidopsis aar mutants that are defective in regulating ADH expression during hypoxia. In this report, we showed that aar1 is a mutation at the NPC6 locus (At3g48610), which encodes a novel membrane-bound phospholipase C. Application of exogenous methyl jasmonate (MeJA) resulted in an increased in ADH mRNA in wild-type and in aar1, albeit at a lower level. These results suggest jasmonic acid (JA) might function as a secondary messenger in NPC6 signaling during hypoxia. Consistent with this hypothesis, we found that hypoxia induction of MYC2, a transcription factor that mediates JA responses, is affected in aar1. In addition to hypoxia, cold stress also induces ADH expression. However, cold-induced ADH expression is not affected by the aar1 mutation nor mediated by AtMYC2. We therefore propose two environmental stress signaling pathways that lead to ADH expression: a hypoxia induced pathway that requires JA, and a cold induced pathway that is independent of JA.
Log in to add this item to your schedule
1 - University of Iowa, Dept of Biological Sciences and Roy J. Carver Center for Comparative Genomics, 206 BBE, U of Iowa, Iowa City, Iowa, 52242, USA
2 - University of Iowa, Dept of Biological Sciences and Roy J. Carver Center for Comparative Genomics
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM