Genome-wide identification of soybean microRNAs and their targets reveals their organ-specificity and responses to phosphate starvation

BMC Genomics

Research Article

Thomas Walk¹  Feng Xu²  Qian Liu²  Luying Chen²  Hong Liao²  Jinxiang Wang²  Jiebin Kuang² 

[1] State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, 510642, Guangzhou, PR China;State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, 510642, Guangzhou, PR China;Root Biology Center, College of Natural Resources and Environment, South China Agricultural University, 510642, Guangzhou, PR China;

关键词: MicroRNA;    Soybean;    Phosphorus;    Root;    Leaf;    Genome;    Degradome;    RLM-5’ RACE;    Deep sequencing;   

DOI  :  10.1186/1471-2164-14-66

 received in 2012-07-11, accepted in 2013-01-11,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundPhosphorus (P) plays important roles in plant growth and development. MicroRNAs involved in P signaling have been identified in Arabidopsis and rice, but P-responsive microRNAs and their targets in soybean leaves and roots are poorly understood.ResultsUsing high-throughput sequencing-by-synthesis (SBS) technology, we sequenced four small RNA libraries from leaves and roots grown under phosphate (Pi)-sufficient (+Pi) and Pi-depleted (-Pi) conditions, respectively, and one RNA degradome library from Pi-depleted roots at the genome-wide level. Each library generated ∼21.45−28.63 million short sequences, resulting in ∼20.56−27.08 million clean reads. From those sequences, a total of 126 miRNAs, with 154 gene targets were computationally predicted. This included 92 new miRNA candidates with 20-23 nucleotides that were perfectly matched to the Glycine max genome 1.0, 70 of which belong to 21 miRNA families and the remaining 22 miRNA unassigned into any existing miRNA family in miRBase 18.0. Under both +Pi and -Pi conditions, 112 of 126 total miRNAs (89%) were expressed in both leaves and roots. Under +Pi conditions, 12 leaf- and 2 root-specific miRNAs were detected; while under -Pi conditions, 10 leaf- and 4 root-specific miRNAs were identified. Collectively, 25 miRNAs were induced and 11 miRNAs were repressed by Pi starvation in soybean. Then, stem-loop real-time PCR confirmed expression of four selected P-responsive miRNAs, and RLM-5’ RACE confirmed that a PHO2 and GmPT5, a kelch-domain containing protein, and a Myb transcription factor, respectively are targets of miR399, miR2111, and miR159e-3p. Finally, P-responsive cis-elements in the promoter regions of soybean miRNA genes were analyzed at the genome-wide scale.ConclusionsLeaf- and root-specific miRNAs, and P-responsive miRNAs in soybean were identified genome-wide. A total of 154 target genes of miRNAs were predicted via degradome sequencing and computational analyses. The targets of miR399, miR2111, and miR159e-3p were confirmed. Taken together, our study implies the important roles of miRNAs in P signaling and provides clues for deciphering the functions for microRNA/target modules in soybean.

【 授权许可】

Unknown   
© Xu et al.; licensee BioMed Central Ltd. 2013. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.