Diurnal changes in the transcriptome encoding enzymes of starch metabolism provide evidence for both transcriptional and posttranscriptional regulation of starch metabolism in arabidopsis leaves
Diurnal changes in the transcriptome encoding enzymes of starch metabolism provide evidence for both transcriptional and posttranscriptional regulation of starch metabolism in arabidopsis leaves
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DOI：
10.1104/pp.104.044347
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发表时间：
2004-09-01
期刊：
影响因子：
7.4
通讯作者：
Smith, AM
中科院分区：
文献类型：
--
作者：
Smith, SM;Fulton, DC;Smith, AM
为了深入了解拟南芥 L. Heynth 叶子中淀粉代谢酶的合成和功能，使用 Affymetrix 微阵列分析整个昼夜周期的转录组。在所采用的条件下，短暂叶淀粉在 12 小时黑暗期间逐渐降解，然后在接下来的 12 小时光照期间积累。编码淀粉合成酶的转录本在 24 小时内变化相对较小，除了两种淀粉合酶、颗粒结合淀粉合酶和淀粉合酶 11 外，它们在从暗到亮的过渡过程中明显增加。编码颗粒结合淀粉合酶的 RNA 的增加可能反映了淀粉颗粒在黑暗中的广泛破坏。编码几种被认为与淀粉分解有关的酶的转录本显示出在黑暗中协调下降，然后在光照中快速积累。尽管转录物水平发生显着变化，但一些淀粉代谢酶的量在昼夜周期中并没有明显变化。转录后调节对于维持体内酶的量及其活性的控制至关重要。尽管转录水平、酶活性和淀粉代谢的昼夜代谢之间的关系很复杂，但已知参与淀粉代谢的酶的一些独特的昼夜转录模式的存在有助于识别可能参与该过程的其他蛋白质。
To gain insight into the synthesis and functions of enzymes of starch metabolism in leaves of Arabidopsis L. Heynth, Affymetrix microarrays were used to analyze the transcriptome throughout the diurnal cycle. Under the conditions employed, transitory leaf starch is degraded progressively during a 12-h dark period, and then accumulates during the following 12-h light period. Transcripts encoding enzymes of starch synthesis changed relatively little in amount over 24 h except for two starch synthases, granule bound starch synthase and starch synthase 11, which increased appreciably during the transition from dark to light. The increase in RNA encoding granule-bound starch synthase may reflect the extensive destruction of starch granules in the dark. Transcripts encoding several enzymes putatively involved in starch breakdown showed a coordinated decline in the dark followed by rapid accumulation in the light. Despite marked changes in their transcript levels, the amounts of some enzymes of starch metabolism do not change appreciably through the diurnal cycle. Posttranscriptional regulation is essential in the maintenance of amounts of enzymes and the control of their activities in vivo. Even though the relationships between transcript levels, enzyme activity, and diurnal metabolism of starch metabolism are complex, the presence of some distinctive diurnal patterns of transcripts for enzymes known to be involved in starch metabolism facilitates the identification of other proteins that may participate in this process.