Genomic analysis of a nutrient response in arabidopsis reveals diverse expression patterns and novel metabolic and potential regulatory genes induced by nitrate
Genomic analysis of a nutrient response in arabidopsis reveals diverse expression patterns and novel metabolic and potential regulatory genes induced by nitrate
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DOI：
10.1105/tpc.12.8.1491
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发表时间：
2000-08-01
期刊：
影响因子：
11.6
通讯作者：
Crawford, NM
中科院分区：
文献类型：
--
作者：
Wang, RC;Guegler, K;Crawford, NM
进行微阵列和RNA凝胶印迹分析来鉴定在低（250μM）和高（5至10mM）硝酸盐浓度下对硝酸盐有反应的拟南芥基因。直接或间接参与亚硝酸盐还原的基因受硝酸盐诱导程度最高。大多数已知的硝酸盐调节基因（包括编码硝酸盐还原酶、硝酸盐转运蛋白 NRT1 和谷氨酸合酶的基因）出现在所研究的 5524 个基因/克隆的至少一个微阵列上的 40 个最强烈的硝酸盐诱导基因/克隆中。还发现了新的硝酸盐诱导基因，包括编码（1）可能的调节蛋白的基因，包括 MYB 转录因子、钙反向转运蛋白和推定的蛋白激酶； (2)代谢酶，包括非氧化性戊糖途径的转醛醇酶和转酮醇酶、苹果酸脱氢酶、天冬酰胺合成酶、组氨酸脱羧酶； (3) 功能未知的蛋白质，包括非共生血红蛋白、一种衰老相关蛋白和两种甲基转移酶。对于许多这些基因观察到的主要诱导模式是在低硝酸盐浓度下mRNA短暂增加，并且在用高硝酸盐浓度处理时持续增加。观察到的其他诱导模式包括低硝酸盐和高硝酸盐处理后的短暂诱导以及任一处理后mRNA量的持续或增加。两个基因，编码铵转运蛋白的 AMT1;1 和编码 MADS-box 因子的 ANR1，被硝酸盐抑制。这些发现表明，硝酸盐在拟南芥中不仅诱导一种反应，而且在 mRNA 水平上诱导多种不同的反应。
Microarray and RNA gel blot analyses were performed to identify Arabidopsis genes that responded to nitrate at both low (250 mu M) and high (5 to 10 mM) nitrate concentrations. Genes involved directly or indirectly with nitrite reduction were the most highly induced by nitrate. Most of the known nitrate-regulated genes (including those encoding nitrate reductase, the nitrate transporter NRT1, and glutamate synthase) appeared in the 40 most strongly nitrate-induced genes/clones on at least one of the microarrays of the 5524 genes/clones investigated. Novel nitrate-induced genes were also found, including those encoding (1) possible regulatory proteins, including an MYB transcription factor, a calcium antiporter, and putative protein kinases; (2) metabolic enzymes, including transaldolase and transketolase of the nonoxidative pentose pathway, malate dehydrogenase, asparagine synthetase, and histidine decarboxylase; and (3) proteins with unknown functions, including nonsymbiotic hemoglobin, a senescence-associated protein, and two methyltransferases. The primary pattern of induction observed for many of these genes was a transient increase in mRNA at low nitrate concentrations and a sustained increase when treated with high nitrate concentrations. Other patterns of induction observed included transient inductions after both low and high nitrate treatments and sustained or increasing amounts of mRNA after either treatment. Two genes, AMT1;1 encoding an ammonium transporter and ANR1 encoding a MADS-box factor, were repressed by nitrate. These findings indicate that nitrate induces not just one but many diverse responses at the mRNA level in Arabidopsis.