Interaction of nitrogen nutrition and salinity in Grey poplar (Populus tremula x alba)
Interaction of nitrogen nutrition and salinity in Grey poplar (Populus tremula x alba)
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DOI：
10.1111/j.1365-3040.2007.01668.x
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发表时间：
2007-07-01
影响因子：
7.3
通讯作者：
Gessler, A.
中科院分区：
文献类型：
--
作者：
Ehlting, B.;Dluzniewska, P.;Gessler, A.
盐度代表了受管理的生态系统中日益严重的环境问题。杨属植物广泛用于施肥种植园中短轮伐期林业的木材生产，并且可以在盐渍土上生长。由于施氮肥在耐盐性中发挥着重要作用，我们分析了用 1 mM 硝酸盐或铵盐（经中等 75 mM NaCl 处理）生长的灰杨（Populus tremula x alba，syn. Populus canescens）。从氮吸收、同化和氮（总氮、蛋白质和氨基化合物）积累等氮代谢的不同水平分析氮营养对改善耐盐性的影响。随着盐暴露时间的推移，所有组织中的钠浓度都会增加。盐暴露对氮营养依赖性的影响在根中比在叶子中更强烈。盐的施用减少了根的增量以及茎高的增加，同时更强烈地增加了铵饲植物根中总氨基化合物的浓度。在叶子中，盐处理更强烈地增加了硝酸盐喂养植物中的总氮浓度，以及独立于氮营养的氨基化合物浓度。暴露于中等盐浓度的灰杨氮代谢的主要变化表现为氨基酸浓度的显着增加。目前的结果表明，当植物用硝酸盐而不是铵作为唯一的氮源时，暴露于盐的灰杨的氮代谢表现得更好。因此，盐渍土上的杨树应优先施硝态氮肥。
Salinity represents an increasing environmental problem in managed ecosystems. Populus spp. is widely used for wood production by short-rotation forestry in fertilized plantations and can be grown on saline soil. Because N fertilization plays an important role in salt tolerance, we analysed Grey poplar (Populus tremula x alba, syn. Populus canescens) grown with either 1 mM nitrate or ammonium subjected to moderate 75 mM NaCl. The impact of N nutrition on amelioration of salt tolerance was analysed on different levels of N metabolism such as N uptake, assimilation and N (total N, proteins and amino compounds) accumulation. Na concentration increased in all tissues over time of salt exposure. The N nutrition-dependent effects of salt exposure were more intensive in roots than in leaves. Application of salt reduced root increment as well as stem height increase and, at the same time, increased the concentration of total amino compounds more intensively in roots of ammonium-fed plants. In leaves, salt treatment increased concentrations of total N more intensively in nitrate-fed plants and concentrations of amino compounds independently of N nutrition. The major changes in N metabolism of Grey poplar exposed to moderate salt concentrations were detected in the significant increase of amino acid concentrations. The present results indicate that N metabolism of Grey poplar exposed to salt performed better when the plants were fed with nitrate instead of ammonium as sole N source. Therefore, nitrate fertilization of poplar plantations grown on saline soil should be preferred.