Identification and functional analysis of miRNAs in developing kernels of a viviparous mutant in maize

作     者：Haiping Ding Jian Gao Mao Luo Hua Peng Haijian Lin Guangsheng Yuan Yaou Shen Maojun Zhao Guangtang Pan Zhiming Zhang 

作者机构：Institute of Maize Research Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region Ministry of AgricultureSichuan Agricultural University Drug Discovery Research Center of Luzhou Medical College Luzhou Medical College Sichuan Tourism University College of Life and Basic ScienceSichuan Agricultural University 

出 版 物：《The Crop Journal》 (作物学报（英文版）)

年 卷 期：2013年第1卷第2期

页      面：115-126页

学科分类：0710[理学-生物学] 09[农学] 0901[农学-作物学] 0902[农学-园艺学] 

基　　金：supported by grants from the Educational Commission of Sichuan Province (No. 2006J13-039) the Doctoral Program Foundation of Institutions of Higher Education of China (No. 20095103120002) the National Natural Science Foundation of China (No. 30900901) 

主　　题：Ear germination-associated miRNAs Microarray hybridization qRT-PCR Zea mays 

摘      要：Given the important roles of miRNAs in post-transcriptional gene regulation, identification of differentially expressed miRNAs will facilitate the elucidation of molecular mechanisms underlying kernel development. In this study, we constructed a small RNA library to comprehensively represent the full complement of individual small RNAs and to characterize miRNA expression profiles in pooled ears of maize(Zea mays L.) at 10, 15,20, 22, 25 and 30 days after pollination(DAP). At least 21 miRNAs were differentially expressed. The differential expression of three of these miRNAs, i.e., miR528a, miR167a and miR160b, at each stage was verified by qRT-PCR. The results indicated that these miRNAs might be involved in kernel development. In addition, the predicted functions of target genes indicated that most of the target genes are involved in signal transduction and cell communication pathways, particularly the auxin signaling pathway. The expression of candidate germination-associated miRNAs was analyzed by hybridization to a maize genome microarray, and revealed differential expression of genes involved in plant hormone signaling pathways. This finding suggests that phytohormones play a critical role in the development of maize kernels. We found that in combination with other miRNAs, miR528a regulated a putative laccase, a Ring-H2 zinc finger protein and a MADS box-like protein, whereas miR167a and miR160b regulated multiple target genes,including ARF(auxin response factor), a member of the B3 transcription factor family. All three miRNAs are important for ear germination, development and physiology. The small RNA transcriptomes and mRNA obtained in this study will help us gain a betterunderstanding of the expression and function of small RNAs in the development of maize kernel.