Response of nitrogen fixation in relation to nodule carbohydrate metabolism in Medicago ciliaris lines subjected to salt stress
Response of nitrogen fixation in relation to nodule carbohydrate metabolism in Medicago ciliaris lines subjected to salt stress
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DOI：
10.1016/j.jplph.2008.06.016
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发表时间：
2009-01-01
影响因子：
4.3
通讯作者：
Abdelly, Chedly
中科院分区：
文献类型：
--
作者：
Ben Salah, Imene;Albacete, Alfonso;Abdelly, Chedly
在两个紫花苜蓿品系中研究了盐胁迫对固氮的影响，与蔗糖向根瘤和其他库器官的运输以及根瘤分解蔗糖的可能性有关。在盐胁迫条件下，两个品系的总生物量产量均有所下降，但TNC 1.8受盐的影响小于TNC 11.9。与 TNC 11.9 相比，TNC 1.8 中的叶绿素含量没有变化。两个品系中的芽、根和根瘤生物量也受到影响，但 TNC 1.8 显示出这些器官的更高的生物量生产潜力。两个品系的固氮能力也有所下降，并且对盐的敏感性比对生长参数的敏感性更高。 TNC 1.8 始终表现出较高的固氮值。与根瘤不同，两个品系的叶子均状况良好。提供营养素，但有一些例外。具体而言，敏感齿叶中的钙含量下降，而根瘤镁含量在任一系中均没有变化。耐受品系在其叶子中积累了更多的钠。两条线的根瘤钠含量没有任何差异。蔗糖向根瘤的分配受到两条系中盐的影响，但这种限制似乎并不影响蔗糖在库器官之间的重新分配。盐胁迫引起两个尖齿中根节蔗糖分解活性的扰动。对蔗糖合成酶有抑制作用，但在TNC 11.9中抑制作用更明显； TNC 1.8 中的碱性/中性活性没有改变，而 TNC 11.9 中的碱性/中性活性降低了一半以上。因此，TNC 1.8 对盐胁迫的相对耐受性可归因于根瘤更好地利用这些光同化物以及苹果酸中类菌的更好供应。盐胁迫下根瘤和其他库器官之间对蔗糖竞争的假设无法得到证实。 (C) 2008 爱思唯尔有限公司。版权所有。
The effect of salt stress on nitrogen fixation, in relation to sucrose transport towards nodules and other sink organs and the potential of sucrose breakdown by nodules, was investigated in two lines of Medicago ciliaris. Under salt stress conditions, the two lines showed a decrease of total biomass production, but TNC 1.8 was less affected by salt than TNC 11.9. The chlorophyll content was not changed in TNC 1.8, in contrast to TNC 11.9. Shoot, root, and nodule biomass were also affected in the two lines, but TNC 1.8 exhibited the higher potentialities of biomass production of these organs. Nitrogen fixation also decreased in the two lines, and was more sensitive to salt than growth parameters. TNC 1.8 consistently exhibited the higher values of nitrogen fixation. Unlike nodules, leaves of both lines were well. supplied in nutrients with some exceptions. Specifically, the calcium content decreased in the sensitive tine leaves, and the nodule magnesium content was not changed in either line. The tolerant line accumulated more sodium in its leaves. The two lines did not show any differences in the nodule sodium content. Sucrose allocation towards nodules was affected by salt in the two lines, but this constraint did not seem to affect the repartition of sucrose between sink organs. Salt stress induced perturbations in nodule sucrolytic activities in the two tines. It inhibited sucrose synthase, but the inhibition was more marked in TNC 11.9; alkaline/neutral activity was not altered in TNC 1.8, whereas it decreased more than half in TNC 11.9. Thus, the relative tolerance of TNC 1.8 to salt stress could be attributed to a better use of these photoassimilates by nodules and a better supply of bacteroids in malate. The hypothesis of a competition for sucrose between nodules and other sink organs under salt stress could not be verified. (C) 2008 Elsevier GmbH. All rights reserved.