Changes in the salinity tolerance of sweet pepper plants as affected by nitrogen form and high CO₂ concentration

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• 作者：Marí ; a C. Piñ ; ero ; Margarita Pé ; rez-Jimé ; nez ; Josefa Ló ; pez-Marí ; n ; Francisco M. del Amor ; ^{franciscom.delamor@carm.es" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Climate change ; Ammonium ; Nitrate ; Carbon dioxide ; Abiotic stress ; Gas exchange
• 刊名：Journal of Plant Physiology
• 出版年：2016
• 出版时间：1 August 2016
• 年：2016
• 卷：200
• 期：Complete
• 页码：18-27
• 全文大小：2303 K

文摘

The assimilation and availability of nitrogen in its different forms can significantly affect the response of primary productivity under the current atmospheric alteration and soil degradation. An elevated CO₂ concentration (e[CO₂]) triggers changes in the efficiency and efficacy of photosynthetic processes, water use and product yield, the plant response to stress being altered with respect to ambient CO₂ conditions (a[CO₂]). Additionally, NH₄⁺ has been related to improved plant responses to stress, considering both energy efficiency in N-assimilation and the overcoming of the inhibition of photorespiration at e[CO₂]. Therefore, the aim of this work was to determine the response of sweet pepper plants (Capsicum annuum L.) receiving an additional supply of NH₄⁺ (90/10 NO₃⁻/NH₄⁺) to salinity stress (60 mM NaCl) under a[CO₂] (400 μmol mol⁻¹) or e[CO₂] (800 μmol mol⁻¹). Salt-stressed plants grown at e[CO₂] showed DW accumulation similar to that of the non-stressed plants at a[CO₂]. The supply of NH₄⁺ reduced growth at e[CO₂] when salinity was imposed. Moreover, NH₄⁺ differentially affected the stomatal conductance and water use efficiency and the leaf Cl⁻, K⁺, and Na⁺ concentrations, but the extent of the effects was influenced by the [CO₂]. An antioxidant-related response was prompted by salinity, the total phenolics and proline concentrations being reduced by NH₄⁺ at e[CO₂]. Our results show that the effect of NH₄⁺ on plant salinity tolerance should be globally re-evaluated as e[CO₂] can significantly alter the response, when compared with previous studies at a[CO₂].