NaCl stress effects on enzymes involved in nitrogen assimilation pathway in tomato "Lycopersicon esculentum" seedlings
NaCl stress effects on enzymes involved in nitrogen assimilation pathway in tomato "Lycopersicon esculentum" seedlings
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DOI：
10.1016/j.jplph.2005.09.012
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发表时间：
2006-12-01
影响因子：
4.3
通讯作者：
Ghorbel, Mohamed Habib
中科院分区：
文献类型：
--
作者：
Debouba, Mohamed;Gouia, Houda;Ghorbel, Mohamed Habib
番茄植株(番茄(Lycopersicesculentum Mitt，cv.在对照培养基上生长10天的Chibli F1)分别暴露在不同浓度的氯化钠(0、25、50和100 mM)中。盐度升高导致叶片和根的干重产量和蛋白质含量下降。反之，根冠比(R/S)随盐度的增加而增大。叶片和根中Na+和Cl-的积累与K+和NO3-的下降有关。盐胁迫下，硝酸还原酶(NR，EC 1.6.6.1)和谷氨酰胺合成酶(GS，EC 6.3.1.2)活性在叶片中受到抑制，而在根中增强。叶片和根中的亚硝酸盐还原酶(NIR，EC 1.7.7.1)活性均降低。叶片和根中的盐度抑制了谷氨酸脱氢酶(GDH，EC 1.4.1.2)的脱氨活性，而显著刺激了谷氨酸脱氢酶的氨化功能。在高盐浓度下，叶片和根中烟酰胺腺嘌呤二核苷酸还原(NADH)-GDH活性随着NH4+含量的增加和蛋白水解酶活性的增加而受到刺激。在盐胁迫方面，讨论了参与氮同化的酶的不同敏感性。(C)2005年爱思唯尔股份有限公司。版权所有。
Tomato plants (Lycopersicon esculentum Mitt, cv. Chibli F1) grown for 10 days on control medium were exposed to differing concentrations of NaCl (0, 25, 50, and 100 mM). Increasing salinity led to a decrease of dry weight (DW) production and protein contents in the leaves and roots. Conversely, the root to shoot (R/S) DW ratio was increased by salinity. Na+ and Cl- accumulation were correlated with a decline of K+ and NO3- in the leaves and roots. Under salinity, the activities of nitrate reductase (NR, EC 1.6.6.1) and glutamine synthetase (GS, EC 6.3.1.2) were repressed in the leaves, while they were enhanced in the roots. Nitrite reductase (NiR, EC 1.7.7.1) activity was decreased in both the leaves and roots. Deaminating activity of glutamate dehydrogenase (GDH, EC 1.4.1.2) was inhibited, whereas the aminating function was significantly stimulated by salinity in the leaves and roots. At a high salt concentration, the nicotinamide adenine dinucleotide reduced (NADH)-GDH activity was stimulated concomitantly with the increasing NH4+ contents and proteolysis activity in the leaves and roots. With respect to salt stress, the distinct sensitivity of the enzymes involved in nitrogen assimilation is discussed. (c) 2005 Elsevier GmbH. All rights reserved.