MicroRNAs （miRNAs） are non-coding small RNAs, which play important regulatory roles in response to biotic and abiotic stresses. Dongxiang wild rice （Oryza rufipogon, DXWR） can survive in extreme drought environmen...MicroRNAs （miRNAs） are non-coding small RNAs, which play important regulatory roles in response to biotic and abiotic stresses. Dongxiang wild rice （Oryza rufipogon, DXWR） can survive in extreme drought environment, but its molecular mechanism of drought resistance is still largely unknown. To further explore miRNA regulatory mechanisms involved in drought resistance, we identified 138 novel miRNAs in DXWR using small RNA sequencing and bioinformatics approaches, and found that the expression levels of 67 novel miRNAs were significantly affected by drought stress. In total, 200 candidate target genes were predicted and annotated for the drought stress-responsive novel miRNAs. Gene Ontology （GO） analysis and Kyoto Encyclopedia of Genes and Genomes （KEGG） pathways suggested that most of the target genes were related to metabolism. Stem-loop quantitative real-time PCR （qRT-PCR） results exhibited high concordance with sequencing data, which confirmed that miRNA expression patterns based on small RNA sequencing in the present study were reliable. Meanwhile, qRT-PCR validated the inverse expression patterns between several miRNAs and their target genes. These results will enhance our understanding of miRNA regulatory mechanisms in response to drought stress in DXWR, and can serve as an important reference for the protection and utilization of this valuable genetic resource.展开更多
Upland cotton （Gossypium hirsutum L.） is an allotetraploid species originated from interspecific hybridization between AA-genome diploid （G. arboretum） and DD-genome diploid （G. raimondii） （Wendel et al., 1992...Upland cotton （Gossypium hirsutum L.） is an allotetraploid species originated from interspecific hybridization between AA-genome diploid （G. arboretum） and DD-genome diploid （G. raimondii） （Wendel et al., 1992）. Cotton fibers are single-celled trichomes that emerge from the ovule epidermal cells. Indexed by the number of days post-anthesis （dpa）, fiber morphogenesis includes four distinct but overlapping steps： initiation （0-3 dpa）, elongation （3-20 dpa）, secondary cell wall thickening （15-45 dpa） and maturation （40-60 dpa） （Yang et al., 2008, Du et al., 2013）. The efficiency and duration of each morphogenesis stage is important to the quality attributes of the mature fiber. Cell elongation is critical for fiber length, whereas secondary cell wall thickening is important for fiber fineness and strength （Meinert and Delmer, 1977）.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.31660386)the Natural Science Foundation of Jiangxi Province for Distinguished Young Scholars(Grant No.20171 BCB23040)+1 种基金the Foundation of Jiangxi Educational Committee(Grant No.GJJ170193)the Sponsored Program for Distinguished Young Scholars in Jiangxi Normal University,China
文摘MicroRNAs （miRNAs） are non-coding small RNAs, which play important regulatory roles in response to biotic and abiotic stresses. Dongxiang wild rice （Oryza rufipogon, DXWR） can survive in extreme drought environment, but its molecular mechanism of drought resistance is still largely unknown. To further explore miRNA regulatory mechanisms involved in drought resistance, we identified 138 novel miRNAs in DXWR using small RNA sequencing and bioinformatics approaches, and found that the expression levels of 67 novel miRNAs were significantly affected by drought stress. In total, 200 candidate target genes were predicted and annotated for the drought stress-responsive novel miRNAs. Gene Ontology （GO） analysis and Kyoto Encyclopedia of Genes and Genomes （KEGG） pathways suggested that most of the target genes were related to metabolism. Stem-loop quantitative real-time PCR （qRT-PCR） results exhibited high concordance with sequencing data, which confirmed that miRNA expression patterns based on small RNA sequencing in the present study were reliable. Meanwhile, qRT-PCR validated the inverse expression patterns between several miRNAs and their target genes. These results will enhance our understanding of miRNA regulatory mechanisms in response to drought stress in DXWR, and can serve as an important reference for the protection and utilization of this valuable genetic resource.
基金supported by the grants from the State Key Basic Research and Development Plan (No. 2010CB126003)the National Transgenic Animals and Plants Research Project (Nos. 2011ZX08005-003 and 2011ZX08009-003)
文摘Upland cotton （Gossypium hirsutum L.） is an allotetraploid species originated from interspecific hybridization between AA-genome diploid （G. arboretum） and DD-genome diploid （G. raimondii） （Wendel et al., 1992）. Cotton fibers are single-celled trichomes that emerge from the ovule epidermal cells. Indexed by the number of days post-anthesis （dpa）, fiber morphogenesis includes four distinct but overlapping steps： initiation （0-3 dpa）, elongation （3-20 dpa）, secondary cell wall thickening （15-45 dpa） and maturation （40-60 dpa） （Yang et al., 2008, Du et al., 2013）. The efficiency and duration of each morphogenesis stage is important to the quality attributes of the mature fiber. Cell elongation is critical for fiber length, whereas secondary cell wall thickening is important for fiber fineness and strength （Meinert and Delmer, 1977）.
