Food safety: Structure and expression of the asparagine synthetase gene family of wheat.
Food safety: Structure and expression of the asparagine synthetase gene family of wheat.
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食品安全：天冬型合成酶基因家族的结构和表达。
DOI：
10.1016/j.jcs.2016.01.010
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发表时间：
2016-03
影响因子：
3.8
通讯作者：
Halford NG
中科院分区：
文献类型：
--
作者：
Gao R;Curtis TY;Powers SJ;Xu H;Huang J;Halford NG
天冬酰胺是一种重要的氮储存和运输分子，但其作为游离氨基酸在作物中的积累对食品安全具有影响，因为游离天冬酰胺是烹饪和加工过程中丙烯酰胺形成的前体。天冬酰胺的合成是由天冬氨酸的酰胺化反应在天冬酰胺合成酶的催化下进行的，本研究关注天冬酰胺合成酶基因在小麦中的表达。三个基因，TaASN 1 -3，在不同的组织和响应氮和硫供应的表达进行了研究。TaASN 2在籽粒发育中后期的胚和胚乳中的表达量是所有组织中最高的。TaASN 1和TaASN 2的表达增加，通过粮食发展，并在粮食中的田间生长的植物在中期发展过程中，响应硫剥夺。然而，只有TaASN 1受到氮或硫供应的盆栽实验，表现出复杂的组织特异性和发展变化的反应。在几种谷类植物的TaASN 1基因启动子中发现了一个推测的N基序或GCN 4样调控基序。随着研究的完成，第四个基因TaASN 4从最近可用的基因组数据中被鉴定出来。系统发育分析表明，其他禾本科物种与小麦具有相似的天冬酰胺合成酶基因家族。三个小麦天冬酰胺合成酶基因表现出差异调节。TaASN 2在谷粒中特异性地高度表达。TaASN 2是降低小麦丙烯酰胺形成潜力的靶标。GCN 4样基序存在于来自多个物种的TaASN 1基因的启动子中。第四个基因TaASN 4可以从小麦基因组数据中识别。
Asparagine is an important nitrogen storage and transport molecule, but its accumulation as a free amino acid in crops has implications for food safety because free asparagine is a precursor for acrylamide formation during cooking and processing. Asparagine synthesis occurs by the amidation of aspartate, catalysed by asparagine synthetase, and this study concerned the expression of asparagine synthetase (TaASN) genes in wheat. The expression of three genes, TaASN1-3, was studied in different tissues and in response to nitrogen and sulphur supply. The expression of TaASN2 in the embryo and endosperm during mid to late grain development was the highest of any of the genes in any tissue. Both TaASN1 and TaASN2 increased in expression through grain development, and in the grain of field-grown plants during mid-development in response to sulphur deprivation. However, only TaASN1 was affected by nitrogen or sulphur supply in pot-based experiments, showing complex tissue-specific and developmentally-changing responses. A putative N-motif or GCN4-like regulatory motif was found in the promoter of TaASN1 genes from several cereal species. As the study was completed, a fourth gene, TaASN4, was identified from recently available genome data. Phylogenetic analysis showed that other cereal species have similar asparagine synthetase gene families to wheat. Three wheat asparagine synthetase genes show differential regulation. TaASN2 is highly expressed specifically in the grain. TaASN2 is a target for reducing the acrylamide-forming potential of wheat. A GCN4-like motif is present in the promoter of TaASN1 genes from multiple species. A fourth gene, TaASN4, is identifiable from wheat genome data.