Regulation of NO(3) Influx in Barley : Studies Using NO(3) |
| |
Authors: | Glass A D Thompson R G Bordeleau L |
| |
Affiliation: | University of British Columbia, Department of Botany, No. 3529 at 6270 University Boulevard, Vancouver, British Columbia, V6T 2B1, Canada. |
| |
Abstract: | Short-term (10 minutes) measurements of plasmalemma NO3− influx ( oc) into roots of intact barley plants were obtained using 13NO3−. In plants grown for 4 days at various NO3− levels (0.1, 0.2, 0.5 millimolar), oc was found to be independent of the level of NO3− pretreatment. Similarly, pretreatment with Cl− had no effect upon plasmalemma 13NO3− influx. Plants grown in the complete absence of 13NO3− (in CaSO4 solutions) subsequently revealed influx values which were more than 50% lower than for plants grown in NO3−. Based upon the documented effects of NO3− or Cl− pretreatments on net uptake of NO3−, these observations suggest that negative feedback from vacuolar NO3− and/or Cl− acts at the tonoplast but not at the plasmalemma. When included in the influx medium, 0.5 millimolar Cl− was without effect upon 13NO3− influx, but NH4+ caused approximately 50% reduction of influx at this concentration. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|