<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Mata, C</style></author><author><style face="normal" font="default" size="100%">Scheurwater, I</style></author><author><style face="normal" font="default" size="100%">MartinsLoucao, M A</style></author><author><style face="normal" font="default" size="100%">Lambers, H</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Root respiration, growth and nitrogen uptake of Quercus suber seedlings</style></title><secondary-title><style face="normal" font="default" size="100%">PLANT PHYSIOLOGY AND BIOCHEMISTRY</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">NH4+</style></keyword><keyword><style  face="normal" font="default" size="100%">NO3-</style></keyword><keyword><style  face="normal" font="default" size="100%">Relative growth rate</style></keyword><keyword><style  face="normal" font="default" size="100%">root respiration</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1996</style></year></dates><publisher><style face="normal" font="default" size="100%">GAUTHIER-VILLARS</style></publisher><pub-location><style face="normal" font="default" size="100%">S P E S-JOURNAL DEPT, 120 BD ST GERMAIN, F-75006 PARIS, FRANCE</style></pub-location><volume><style face="normal" font="default" size="100%">34</style></volume><pages><style face="normal" font="default" size="100%">727-734</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We tested the influence of two N-sources, NO3- and NH4+, on root growth&lt;br/&gt;and respiration of Quercus suber L. Seedlings were grown on hydroponics&lt;br/&gt;with 0.5 mM N as NO3- or NH4+ in a growth chamber. Root relative growth&lt;br/&gt;rate (RGR) of NO3--fed seedlings ranged from 9 to 34 mg g(-1) day(-1).&lt;br/&gt;These values are lower than those described for slow-growing herbaceous&lt;br/&gt;and for most woody species. Root respiration and the activity and&lt;br/&gt;capacity of the alternative pathway (AP) showed no differences between&lt;br/&gt;the two N-sources. Both activity and capacity of the AP were very low&lt;br/&gt;and the cytochrome pathway was fully engaged. Specific respiratory costs&lt;br/&gt;were calculated for maintenance, 6.3 nmol O-2 g(-1) s(-1), for nitrate&lt;br/&gt;uptake, 0.99 mol O-2 mol N-1, and for growth 5.4 mmol O-2 g(-1). These&lt;br/&gt;values are similar to those found for slow-growing herbaceous species.&lt;br/&gt;The major part of total root respiration, over 64%, was used for&lt;br/&gt;maintenance processes, and a much smaller fraction for growth and&lt;br/&gt;nitrate uptake.</style></abstract></record></records></xml>