MicroRNA (miR396) negatively regulates expression of ceramidase-like genes in Arabidopsis  

作　　者：Dongmei Liu Diqiu Yu 

机构地区：[1]Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming 650223, China [2]Graduate School of the Chinese Academy of Sciences, Beijing 100049, China

出　　处：《Progress in Natural Science:Materials International》2009年第6期781-785,共5页自然科学进展·国际材料（英文版）

基　　金：supported by the National Hi-Tech Research and Development Program of China (Grant No.2006AA02Z129);the National Natural Science Foundation of China (Grant No.90408022);the Science Foundation of Yunnan Province (Grant No.2004C0051M)

摘　　要：MicroRNAs （miRNAs） are 21-23 nucleotide （nt）, endogenous RNAs that regulate gene expression by targeting mRNAs for direct cleavage or translational repression in plants. In Arabidopsis, miR396 is encoded by two different loci （MIR396a and MIR396b） and sequence analysis suggests it may target three ceramidase-like genes （Atceramidase-like 1, Ateeramidase-like 2 and Atceramidase-like 3）. To demonstrate the biological function of miR396, we inserted the synthetic precursors, MIR396a or MIR396b, under the control of the enhanced cauliflower mosaic virus （CaMV） 35S promoter, into a plant transformation vector （pOCA30） and transformed the constructs into Arabidopsis. The promoter increased miR396 levels by more than 2-fold, indicating appropriate maturation of the synthetic precursor MIR396a or MIR396b transcript in transgenic plants. Microarray analysis showed that the transcript levels of two ceramidaselike genes （Atceramidase-like 1, Atceramidase-like 2） were decreased by more than 2-fold and lactosylceramide 4-α-galactosyltransferase increased by more than 2-fold in transgenic plants compared with the empty vector-transformed plants. Northern blot analysis showed that the mRNA levels of the two ceramidase-like genes were significantly reduced in transgenic plants. These results indicated that miR396 probably plays a crucial role in the ceramide metabolism pathway by negatively regulating the expression of ceramidase-like genes in Arabidopsis.MicroRNAs (miRNAs) are 21-23 nucleotide (nt), endogenous RNAs that regulate gene expression by targeting mRNAs for direct cleavage or translational repression in plants. In Arabidopsis, miR396 is encoded by two different loci (MIR396a and MIR396b) and sequence analysis suggests it may target three ceramidase-like genes (Atceramidase-like 1, Atceramidase-like 2 and Atceramidase-like 3). To demonstrate the biological function of miR396, we inserted the synthetic precursors, MIR396a or MIR396b, under the control of the enhanced cauliflower mosaic virus (CaMV) 35S promoter, into a plant transformation vector (pOCA30) and transformed the constructs into Arabidopsis. The promoter increased miR396 levels by more than 2-fold, indicating appropriate maturation of the synthetic precursor MIR396a or MIR396b transcript in transgenic plants. Microarray analysis showed that the transcript levels of two ceramidase-like genes (Atceramidase-like 1, Atceramidase-like 2) were decreased by more than 2-fold and lactosylceramide 4-a-galactosyltransferase increased by more than 2-fold in transgenic plants compared with the empty vector-transformed plants. Northern blot analysis showed that the mRNA levels of the two ceramidase-like genes were significantly reduced in transgenic plants. These results indicated that miR396 probably plays a crucial role in the ceramide metabolism pathway by negatively regulating the expression of ceramidase-like genes in Arabidopsis.

关 键 词：miR396 miR396 precursor CERAMIDASE CERAMIDE 

分 类 号：Q78[生物学—分子生物学] Q522