A potential gateway for stress-specific preferential translation 1 in Arabidopsis

Reprogramming of gene expression is one of the key responses to environmental stimuli, whereas changes in mRNA do not necessarily bring forth corresponding changes of the protein. We investigated the coordination and discordance between transcription and translation under different stresses in Arabidopsis and found that a substantial fraction of total mRNAs were present in the polysomes, however, to a large extent, the mRNAs were not evenly loaded with ribosomes. Notably, typical stress responsive genes were coordinately regulated at both transcriptional and translational levels, while stress irrelevant genes were changed solely at a single level, suggesting that stress-specific ribosome loading onto the existing mRNAs pool could be a pacing factor for preferential translation.

基因表达重编程是生物体应对环境刺激的核心响应之一，而信使RNA（messenger RNA）水平的变化未必会对应引发蛋白质的相应改变。本研究针对拟南芥（Arabidopsis）在不同胁迫条件下的转录与翻译协同及失调情况展开探究，结果发现，总信使RNA中有相当一部分存在于多核糖体（polysome）中，但在很大程度上，这些信使RNA并未均匀结合核糖体。值得注意的是，典型的胁迫响应基因在转录和翻译水平上均受到协同调控，而非胁迫相关基因则仅在单一水平上发生表达变化，这表明胁迫特异性的核糖体结合至现有信使RNA库（mRNA pool）的过程，可能是介导优先翻译的节奏调控因子。