Abstract：
We assumed that miRNAs might regulate the physiological and biochemical processes in plants through their effects on the redox system and phytohormones. To check this hypothesis, the transcriptome profile of wild-type Arabidopsis and lines with decreased ascorbate (Asc), glutathione (GSH), or salicylate (Sal) levels were compared. GSH deficiency did not influence the miRNA expression, whereas lower levels of Asc and Sal reduced the accumulation of 9 and 44 miRNAs, respectively, but only four miRNAs were upregulated. Bioinformatics analysis revealed that their over-represented target genes are associated with the synthesis of nitrogen-containing and aromatic compounds, nucleic acids, and sulphate assimilation. Among them, the sulphate reduction-related miR395 - ATP-sulfurylase couple was selected to check the assumed modulating role of the light spectrum. A greater induction of the Asc- and Sal-responsive miR395 was observed under sulphur starvation in far-red light compared to white and blue light in wild-type and GSH-deficient Arabidopsis lines. Sal deficiency inhibited the induction of miR395 by sulphur starvation in blue light, whereas Asc deficiency greatly reduced it independently of the spectrum. Interestingly, sulphur starvation decreased only the level of ATP sulfurylase 4 among the miR395 target genes in far-red light. The expression level of ATP sulfurylase 3 was higher in far-red light than in blue light in wild-type and Asc-deficient lines. The results indicate the coordinated control of miRNAs by the redox and hormonal system since 11 miRNAs were affected by both Asc and Sal deficiency. This process can be modulated by light spectrum, as shown for miR395.
摘要：
我们假设miRNAs可能通过对氧化还原系统和植物激素的影响来调节植物的生理和生化过程。为了验证这个假设，野生型拟南芥和抗坏血酸（Asc）减少的品系的转录组谱，谷胱甘肽(GSH),或水杨酸（Sal）水平进行比较。GSH缺乏不影响miRNA的表达，而较低水平的Asc和Sal减少了9和44个miRNA的积累，分别,但只有4个miRNAs上调。生物信息学分析显示,其过度表达的靶基因与含氮化合物和芳香族化合物的合成有关,核酸,和硫酸盐同化。其中,选择与硫酸盐还原相关的miR395-ATP-硫酸化酶对来检查假定的光谱调节作用。与野生型和缺乏GSH的拟南芥品系中的白光和蓝光相比，在远红光下硫饥饿下观察到了对Asca和Sal响应性miR395的更大诱导。Sal缺乏抑制了蓝光中硫饥饿对miR395的诱导，而Asc缺乏极大地降低了它独立于光谱。有趣的是,在远红光下，硫饥饿仅降低了miR395靶基因中ATP硫酸化酶4的水平。野生型和Asc缺陷系的ATP硫酸化酶3在远红光中的表达水平高于蓝光。结果表明，氧化还原和激素系统对miRNA的协调控制，因为11种miRNA受到Asc和Sal缺乏的影响。这个过程可以通过光谱来调制，如miR395所示。
