title: Characterization of drought- and heat-responsive microRNAs in switchgrass.
abstract: Recent investigations revealed that microRNAs (miRNAs) play crucial roles in plant acclimation to stress conditions. Switchgrass, one of the important biofuel crop species can withstand hot and dry climates but the molecular basis of stress tolerance is relatively unknown. To identify miRNAs that are important for tolerating drought or heat, small RNAs were profiled in leaves of adult plants exposed to drought or heat. Sequence analysis enabled the identification of 29 conserved and 62 novel miRNA families. Notably, the abundances of several conserved and novel miRNAs were dramatically altered following drought or heat. Using at least one fold (log2) change as cut off, we observed that 13 conserved miRNA families were differentially regulated by both stresses, and, five and four families were specifically regulated by drought and heat, respectively. Similarly, using a more stringent cut off of two fold (log2) regulation, we found 5 and 16 novel miRNA families were upregulated but 6 and 7 families were downregulated under drought and heat, respectively. The stress-altered expression of a subset of miRNAs and their targets was confirmed using quantitative PCR. Overall, the switchgrass plants exposed to drought or heat revealed similarities as well as differences with respect to miRNA regulation, which could be important for enduring different stress conditions.
authors.affiliation: Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA.
authors.forename: Vandana
authors.initials: V
authors.lastname: Hivrale
authors.affiliation: Faculty of Life Science and Technology, Kunming University of Science and Technology, 727 South Jingming Road, Kunming, Yunnan 650500, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA.
authors.forename: Chandra Obul Reddy
authors.initials: COR
authors.lastname: Puli
authors.affiliation: Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA.
authors.forename: Guru
authors.initials: G
authors.lastname: Jagadeeswaran
authors.affiliation: Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA.
authors.forename: Kanchana
authors.initials: K
authors.lastname: Gowdu
authors.affiliation: Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK 74078, USA.
authors.forename: Vijaya Gopal
authors.initials: VG
authors.lastname: Kakani
authors.affiliation: Department of Biology, University of South Dakota, Vermillion, SD 57069, USA.
authors.forename: Abdelali
authors.initials: A
authors.lastname: Barakat
authors.affiliation: Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA. Electronic address: ramanjulu.sunkar@okstate.edu.
authors.forename: Ramanjulu
authors.initials: R
authors.lastname: Sunkar
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D001483:Base Sequence; D055864:Droughts; D020869:Gene Expression Profiling / Q000379:methods; D018506:Gene Expression Regulation, Plant; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods; D006358:Hot Temperature; D035683:MicroRNAs / Q000235:genetics*; D008897:Panicum / Q000235:genetics*; D018749:RNA, Plant / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D013312:Stress, Physiological / Q000235:genetics
chemical_list: D035683:MicroRNAs; D018749:RNA, Plant
keywords: Biofuel crop; Drought; Heat; MicroRNAs; Switchgrass