Cabañero Francisco J, Carvajal Micaela
Departamento de Nutrición y Fisiología Vegetal, Centro de Edafología y Biología Aplicada del Segura - CSIC, Apdo. Correos 164, 30100 Espinardo, Murcia, Spain.
J Plant Physiol. 2007 Oct;164(10):1300-10. doi: 10.1016/j.jplph.2006.08.010. Epub 2006 Oct 30.
In order to study the effect of nutrient stress on water uptake in pepper plants (Capsicum annuum L.), the excess or deficiency of the main cations involved in plant nutrition (K(+), Mg(2+), Ca(2+)) and two different degrees of salinity were related to the activity of plasma membrane H(+)-ATPase, the pH of the xylem sap, nutrient flux into the xylem (J(s)) and to a number of parameters related to water relations, such as root hydraulic conductance (L(0)), stomatal conductance (g(s)) and aquaporin activity. Excess of K(+), Ca(+) and NaCl produced a toxic effect on L(0) while Mg(2+) starvation produced a positive effect, which was in agreement with aquaporin functionality, but not with ATPase activity. The xylem pH was altered only by Ca treatments. The results obtained with each treatment could suggest that detection of the quality of the nutrient supply being received by roots can be related to aquaporins functionality, but also that each cation stress triggers specific responses that have to be assessed individually.
为了研究营养胁迫对辣椒（Capsicum annuum L.）植株水分吸收的影响，将参与植物营养的主要阳离子（K⁺、Mg²⁺、Ca²⁺）的过量或缺乏以及两种不同程度的盐度与质膜H⁺-ATP酶活性、木质部汁液的pH值、养分向木质部的通量（J(s)）以及一些与水分关系相关的参数，如根系水力导度（L(0)）、气孔导度（g(s)）和水通道蛋白活性联系起来。K⁺、Ca⁺和NaCl过量对L(0)产生毒性作用，而Mg²⁺缺乏产生积极作用，这与水通道蛋白的功能一致，但与ATP酶活性不一致。木质部pH值仅受Ca处理的影响。各处理获得的结果表明，根系所接收的养分供应质量的检测可能与水通道蛋白的功能有关，而且每种阳离子胁迫都会引发必须单独评估的特定反应。
