Grain production of rice (Oryza sativa L.) is a top priority in ensuring food security for human beings. One of the approaches to increase yield is to delay leaf senescence and to extend the available time for photosynthesis. MicroRNAs (miRNAs) are key regulators of aging and cellular senescence in eukaryotes. To help understand their biological role in rice leaf senescence, researchers from Hangzhou Normal University reported identification of miRNAs and their putative target genes by deep sequencing of six small RNA libraries, six RNA-seq libraries and two degradome libraries from the leaves of two super hybrid rice, Nei-2-You 6 (N2Y6, age-resistant rice) and Liang-You-Pei 9 (LYP9, age-sensitive rice). Using LC Sciences’ degradome sequencing service, a total of 372 known miRNAs, 162 miRNA candidates and 1145 targets were identified. Compared with the expression of miRNAs in the leaves of LYP9, the numbers of miRNAs up-regulated and down-regulated in the leaves of N2Y6 were 47 and 30 at early stage of grain-filling, 21 and 17 at the middle stage, and 11 and 37 at the late stage, respectively. Six miRNA families, osa-miR159, osa-miR160 osa-miR164, osa-miR167, osa-miR172 and osa-miR1848, targeting the genes encoding APETALA2 (AP2), zinc finger proteins, salicylic acid-induced protein 19 (SIP19), auxin response factors (ARF) and NAC transcription factors, respectively, were found to be involved in leaf senescence through phytohormone signaling pathways. These results provide valuable information for understanding the miRNA-mediated leaf senescence of rice, and offered an important foundation for rice breeding.

 

Senescence characterization of the leaves at the early, middle and late stages of grain-filling in LYP9 and N2Y6. (A) Senescence phenotype of the leaves; (B) The content of chlorophyll a and chlorophyll b in leaves. 

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miRNA/Small RNA Sequencing Service – miRNA sequencing is a new method and powerful tool to identify and quantitatively decode the entire population of microRNAs in your sample. LC Sciences now provides a comprehensive microRNA sequencing service. [Learn more…]

Degradome Sequencing Service -Degradome sequencing is a modified 5′-rapid amplification of cDNA ends (RACE) with high-throughput next-gen sequencing method. Degradome sequencing has been use to identify microRNA (miRNA) cleavage sites, because miRNAs can cause endonucleolytic cleavage of mRNA by extensive and often perfect complementarity to mRNAs. Degradome sequencing has revealed many known and novel plant miRNA (siRNA) targets.…[Learn more…]


References

Xu X, Bai H, Liu C, Chen E, Chen Q, et al. (2014) Genome-Wide Analysis of MicroRNAs and Their Target Genes Related to Leaf Senescence of Rice. PLoS ONE 9(12): e114313. doi:10.1371/journal.pone.0114313 [article]


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