[Functional Genomics Center Seminar ]
  
    
 ▶Subject: Indications for long-distance lipid signaling in plant development and stress response
 
 ▶Speaker: Prof. Susanne Hoffmann-Benning (Michigan State University)
         
 ▶Date: 3:00PM/Oct./10(Fri)/2014
        
 ▶Place: Auditorium(1F), Postech Biotech Center

 *Abctract
       T Plants cannot escape adverse conditions. They developed efficient detection, signaling, and response mechanisms to adapt to environmental stresses. While many of these responses are local, some require long-distance signaling. We identified lipids and lipid-binding proteins (LBPs) within phloem exudates of Arabidopsis (Guelette et al., 2012). We proposed that these phloem lipids could act as long-distance signals and that phloem LBPs participate in different aspects of this signaling cascade:  (i) release of lipids into the phloem, (ii) solubilization/ transport/component of the lipid-signal, or (iii) receptor for a lipid signal (Benning et al., 2012).
To better understand the role of phloem lipids and LBPs, we are focusing on three predicted lipid-binding proteins:  a putative GDSL-lipase that may release lipids into the phloem; PIG-P, with a predicted role in GPI-anchor and possibly receptor formation; and PLAFP, a lipid-binding protein with unknown function. We have characterized the lipid-binding properties and stress response of all three proteins. One protein, PLAFP binds phosphatidic acid (PA). PA is a known intracellular signal produced in response to salt-stress, drought, and ABA. Yet, no long-distance action of PA has been reported. AtPLAFP is induced by ABA and PEG, both compounds used to signal/mimic water stress. It is expressed in vascular bundles of leaves and roots and in root meristems. Changes in expression levels through mutagenesis or ectopic expression affect root growth and, likely as a consequence, overall plant size and seed yield. We propose that PLAFP controls root development and, thus, seedling establishment and the water/nutrient supply throughout the plant. During water stress, the larger root system of overexpressors should provide a better water supply and thus higher drought tolerance.

 ▶Inquiry: Prof. Youngsook Lee (279-2296)
       
   * This seminar will be given in English