title: A Non-specificSetaria italicaLipid Transfer Protein Gene Plays a Critical Role under Abiotic Stress.
abstract: Lipid transfer proteins (LTPs) are a class of cysteine-rich soluble proteins having small molecular weights. LTPs participate in flower and seed development, cuticular wax deposition, also play important roles in pathogen and abiotic stress responses. A non-specific LTP gene (SiLTP) was isolated from a foxtail millet (Setaria italica) suppression subtractive hybridization library enriched for differentially expressed genes after abiotic stress treatments. A semi-quantitative reverse transcriptase PCR analysis showed thatSiLTPwas expressed in all foxtail millet tissues. Additionally, theSiLTPpromoter drove GUS expression in root tips, stems, leaves, flowers, and siliques of transgenicArabidopsis. Quantitative real-time PCR indicated that theSiLTPexpression was induced by NaCl, polyethylene glycol, and abscisic acid (ABA). SiLTP was localized in the cytoplasm of tobacco leaf epidermal cells and maize protoplasts. The ectopic expression ofSiLTPin tobacco resulted in higher levels of salt and drought tolerance than in the wild type (WT). To further assess the function of SiLTP,SiLTPoverexpression (OE) and RNA interference (RNAi)-based transgenic foxtail millet were obtained.SiLTP-OE lines performed better under salt and drought stresses compared with WT plants. In contrast, the RNAi lines were much more sensitive to salt and drought compared than WT. Electrophoretic mobility shift assays and yeast one-hybrids indicated that the transcription factor ABA-responsive DRE-binding protein (SiARDP) could bind to the dehydration-responsive element ofSiLTPpromoterin vitroandin vivo, respectively. Moreover, theSiLTPexpression levels were higher inSiARDP-OE plants compared than the WT. These results confirmed thatSiLTPplays important roles in improving salt and drought stress tolerance of foxtail millet, and may partly be upregulated by SiARDP.SiLTPmay provide an effective genetic resource for molecular breeding in crops to enhance salt and drought tolerance levels.
authors.affiliation: State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural UniversityBeijing, China; Life Science and Technology Center, China National Seed Group Co., LtdWuhan, China.
authors.forename: Yanlin
authors.initials: Y
authors.lastname: Pan
authors.affiliation: State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University Beijing, China.
authors.forename: Jianrui
authors.initials: J
authors.lastname: Li
authors.affiliation: State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University Beijing, China.
authors.forename: Licong
authors.initials: L
authors.lastname: Jiao
authors.affiliation: State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University Beijing, China.
authors.forename: Cong
authors.initials: C
authors.lastname: Li
authors.affiliation: State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University Beijing, China.
authors.forename: Dengyun
authors.initials: D
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University Beijing, China.
authors.forename: Jingjuan
authors.initials: J
authors.lastname: Yu
keywords: drought tolerance; foxtail millet; lipid transfer protein; salt stress; transcription factor