Abstract
MicroRNAs (miRNAs) play key roles in plant reproduction. However, knowledge on microRNAome analysis in autotetraploid rice is rather limited. Here, high-throughput sequencing technology was employed to analyze miRNAomes during pollen development in diploid and polyploid rice. A total of 172 differentially expressed miRNAs (DEM) were detected in autotetraploid rice compared to its diploid counterpart, and 57 miRNAs were specifically expressed in autotetraploid rice. Of the 172 DEM, 115 and 61 miRNAs exhibited up- and down-regulation, respectively. Gene Ontology analysis on the targets of up-regulated DEM showed that they were enriched in transport and membrane in pre-meiotic interphase, reproduction in meiosis, and nucleotide binding in single microspore stage. osa-miR5788 and osa-miR1432-5p_R+1 were up-regulated in meiosis and their targets revealed interaction with the meiosis-related genes, suggesting that they may involve in the genes regulation associated with the chromosome behavior. Abundant 24 nt siRNAs associated with transposable elements were found in autotetraploid rice during pollen development; however, they significantly declined in diploid rice, suggesting that 24 nt siRNAs may play a role in pollen development. These findings provide a foundation for understanding the effect of polyploidy on small RNA expression patterns during pollen development that cause pollen sterility in autotetraploid rice.
Highlights
The evolutionary history of all angiosperms shows that about 30%–60% of them might be polyploids, whole genome duplication has occurred in 75% of all flowering plants [1,2]
Microarray analysis revealed that the differential gene expressions altered the meiosis gene network that may result in abnormal chromosome behavior and pollen development in autotetraploid rice [14]
To investigate the miRNAs associated with the pollen development of diploid (CK) and autotetraploid rice, three pollen development stages, pre-meiotic interphase (PMA), MA and SCP, were selected to construct six libraries and sequenced by Solexa high-throughput sequencing technology
Summary
The evolutionary history of all angiosperms shows that about 30%–60% of them might be polyploids, whole genome duplication has occurred in 75% of all flowering plants [1,2]. Microarray analysis revealed that the differential gene expressions altered the meiosis gene network that may result in abnormal chromosome behavior and pollen development in autotetraploid rice [14]. We conducted a transcriptomic analysis on allelic interactions in autotetraploid rice hybrids, and the results revealed that polyploidy enhanced F1 pollen sterility loci interactions that alter the expression profiles of meiosis-related or meiosis-stage-specific genes, and resulted in low pollen fertility in autotetraploid rice [15]. We planned this study to investigate the differentially expressed miRNAs between autotetraploid and diploid rice, and to detect novel miRNAs that may be associated with meiosis or other stages during pollen development in autotetraploid rice. The results of the present study will provide insights into the roles of miRNAs during pollen development in autotetraploid rice and their association with pollen fertility
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
