A Non-specific Setaria italica Lipid 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 that SiLTP was expressed in all foxtail millet tissues. Additionally, the SiLTP promoter drove GUS expression in root tips, stems, leaves, flowers, and siliques of transgenic Arabidopsis. Quantitative real-time PCR indicated that the SiLTP expression 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 of SiLTP in tobacco resulted in higher levels of salt and drought tolerance than in the wild type (WT). To further assess the function of SiLTP, SiLTP overexpression (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 of SiLTP promoter in vitro and in vivo, respectively. Moreover, the SiLTP expression levels were higher in SiARDP-OE plants compared than the WT. These results confirmed that SiLTP plays important roles in improving salt and drought stress tolerance of foxtail millet, and may partly be upregulated by SiARDP. SiLTP may provide an effective genetic resource for molecular breeding in crops to enhance salt and drought tolerance levels.

Quantitative Proteomic Analysis of Alligator Weed Leaves Reveals That Cationic Peroxidase 1 Plays Vital Roles in the Potassium Deficiency Stress Response

“…Plant nonspecific lipid transfer proteins (nsLTPs) are low-molecular-mass basic proteins belonging to the plant specific prolamin superfamily. SiLTP-overexpressing Setaria italica exhibited improved tolerance under salt and drought stresses, and its transcription is regulated by the transcription factor ABA-responsive DRE-binding protein [48]. In our study, one nsLTP was up-regulated, and it is vital to identify related transcription factors to elucidate the function of this protein in LK stress.…”

The Barley Stripe Mosaic Virus expression system reveals the wheat C2H2 zinc finger protein TaZFP1B as a key regulator of drought tolerance

“…WAX (#158) and non-specific lipid transfer protein genes (#172, #175-177 and Additional file 4: Fig. S3H) were reported to promote wax synthesis and to participate in cuticular wax deposition, respectively [110,112]. Therefore, these results suggest that TaZFP1B regulates stress-responsive genes known for their capacity to enhance adaptation to drought stress tolerance ( Fig.…”

The barley stripe mosaic virus expression system reveals the wheat C2H2 zinc finger protein TaZFP1B as a key regulator of drought tolerance

“…WAX (#158) and non-specific lipid transfer protein genes (#172, #175-177 and Additional file 4: Fig. S3H) were reported to promote wax synthesis and to participate in cuticular wax deposition, respectively [110,112]. Therefore, these results suggest that TaZFP1B regulates stress-responsive genes known for their capacity to enhance adaptation to drought stress (Fig.…”