A tobacco asparagine synthetase gene responds to carbon and nitrogen status and its root expression is affected under boron stress
A tobacco asparagine synthetase gene responds to carbon and nitrogen status and its root expression is affected under boron stress
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DOI：
10.1016/j.plantsci.2009.12.008
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发表时间：
2010-03-01
期刊：
影响因子：
5.2
通讯作者：
Gonzalez-Fontes, Agustin
中科院分区：
文献类型：
--
作者：
Beato, Victor M.;Rexach, Jesus;Gonzalez-Fontes, Agustin
到目前为止，在烟草中已经鉴定出一个天冬酰胺合成酶(AS)基因。我们的结果表明，该基因编码一个实际的AS蛋白。这一假设得到了以下事实的支持：(1)BLAST分析表明，烟草AS基因与不同植物物种的几个AS基因具有更高的同源性。(2)在光照和黑暗条件下，叶片和根的As基因表达水平与可溶性碳水化合物浓度呈负相关，外源蔗糖抑制了根As基因的表达。(3)在光照条件下，叶片和根的As基因表达水平与叶片和根中的氨含量呈正相关。(4)叶片As基因的表达与天冬酰胺(Asn)浓度呈正相关。此外，实时定量聚合酶链式反应分析表明，缺硼条件下，该基因在根中的表达增加，但在叶片中的表达没有显著差异。我们讨论了可溶性B缺乏在烟草根部As基因表达调控中的可能作用。(C)2010爱思唯尔爱尔兰有限公司保留所有权利。
To date, one asparagine synthetase (AS) mRNA has been identified in Nicotiana tabacum Our results point out that this gene encodes an actual AS protein This proposal is supported by the following facts (i) Blast analysis indicates that tobacco AS gene shows increased percent identity with several AS genes of different plant species. (ii) Leaf and root AS mRNA levels were inversely correlated with soluble carbohydrate concentrations, both in the presence of light and in darkness, and the addition of exogenous sucrose repressed the root AS gene expression (iii) In light, a positive correlation between AS transcript levels and ammonium content was observed in both leaves and roots (iv) A direct correlation between leaf AS gene expression and asparagine (Asn) concentration has been found. Furthermore, quantitative real-tune PCR analyses showed that this gene expression was increased under boron (B) deficiency in roots, but not in leaves Interestingly, soluble B concentration in roots of plants subjected to B deficiency was significantly lower than that of control plants However, in leaves, there was no significant difference in soluble B content between both B treatments. We discuss the possible role of soluble B deficiency in the regulation of AS gene expression in tobacco roots. (C) 2010 Elsevier Ireland Ltd All rights reserved.