International Journal Bioautomation (Dec 2015)
Identification and Analysis of C. annuum microRNAs by High-throughput Sequencing and Their Association with High Temperature and High Air Humidity Stress
Abstract
MicroRNAs (miRNAs) play an important role in many developmental processes and stress responses in plants. In this study, tolerant hot pepper cultivar 'R597' (CaR) and sensitive cultivar 'S590' (CaS) were used to detected differentially expressed miRNAs under high temperatures and high air humidity. The length distribution of obtained small RNAs was significantly different between libraries. There were a total of 71 miRNA families identified in two genotypes, and 24 conserved miRNA families were detected in all four sRNA libraries. MIR166, MIR156/157, MIR167, MIR168, MIR2118, and MIR5301 were highly expressed in four libraries, and 93 miRNAs had a species-specific expression. Among them, 60 miRNAs were preferentially expressed in S590 leaves and 33 miRNAs were preferentially expressed in R597 leaves. Mostly miRNAs were less-conserved miRNAs. The most abundant miRNAs with different expressions between two pepper species was miR6149b, which exhibited a high level (read count 42,443) in CaSCK but no expressed in CaRCK. We found 650 (CaRCK), 1054 (CaRHH), 914 (CaSCK), 1045 (CaSHH) potential targets for 92 (CaRCK), 124 (CaRHH), 128 (CaSCK), 117 (CaSHH) hot pepper miRNAs, respectively. These findings facilitate in better understanding of the molecular mechanism underlying high temperature and high air humidity condition in different pepper genotypes.
