Differential expression of four Arabidopsis PAL genes; PAL1 and PAL2 have functional specialization in abiotic environmental-triggered flavonoid synthesis
Differential expression of four Arabidopsis PAL genes; PAL1 and PAL2 have functional specialization in abiotic environmental-triggered flavonoid synthesis
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DOI：
10.1016/j.jplph.2007.11.005
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发表时间：
2008-01-01
影响因子：
4.3
通讯作者：
Lillo, Cathrine
中科院分区：
文献类型：
--
作者：
Olsen, Kristine M.;Lea, Unni S.;Lillo, Cathrine
苯丙氨酸解氨酶（PAL，EC 4.3.1.5）催化苯丙烷类代谢途径的第一步，并且被认为是初级代谢和次级代谢之间的重要调节点。在目前的工作中，我们分析了PAL基因在拟南芥莲座期植物叶片中的表达，在5至30摄氏度的温度范围内，响应于氮消耗。只有PAL1和PAL2对环境因子，氮和温度反应强烈。无论氮处理，PAL 1和2转录水平增加在5和10 ℃。在所有温度下平均，氮消耗导致PAL 1和PAL 2转录物增加两倍。PAL活性与PAL转录水平相关（R = 0.94）。积累的主要可溶性苯丙素，芥子酸酯和黄酮类化合物，响应降低温度增加。类黄酮，山奈酚，槲皮素和花青素，表现出显着增加的水平，作为氮消耗的结果（两个，五个和六倍的增长，分别）时，在所有温度下平均。PAL1、PAL2和PAL4与木质素的组织特异性合成有关，而本研究表明PAL1和PAL2在非生物环境触发的类黄酮合成中也具有功能特异性。(C)2007年，Elsevier GmbH。All rights reserved.
Phenylalanine ammonia-Lyase (PAL, EC 4.3.1.5) catalyzes the first step in the phenylpropanoid pathway, and is considered an important regulation point between primary and secondary metabolism. In the present work we analyzed expression of the PAL genes in leaves of Arabidopsis thaliana rosette-stage plants in response to nitrogen depletion at temperatures ranging from 5 to 30 degrees C. Only PAL1 and PAL2 responded strongly to both environmental factors, nitrogen and temperature. Regardless of nitrogen treatments, PAL1 and 2 transcript levels increased at 5 and 10 degrees C. Averaged across all temperatures, nitrogen depletion led to a two-fold increase in PAL 1 and PAL2 transcripts. PAL activity was correlated with PAL transcript levels (R = 0.94). Accumulation of major soluble phenylpropanoids, sinapic acid esters and flavonoids, increased in response to lowering temperature. The flavonoids, kaempferols, quercetins and anthocyanins, showed significantly increased levels as a result of nitrogen depletion (two-, five- and six-fold increases, respectively) when averaged across all temperatures. PAL1, PAL2 and PAL4 have previously been shown to be related with tissue-specific lignin synthesis, and the present work shows that PAL 1 and PAL2 also have functional specialization in abiotic environmental-triggered flavonoid synthesis. (C) 2007 Elsevier GmbH. All rights reserved.