Identification of a novel NPR1-like gene from Nicotiana glutinosa and its role in resistance to fungal, bacterial and viral pathogens.
The NPR1 or NPR1-like genes play a pivotal role in systemic acquired resistance in plants. Here, we isolated and identified a novel tobacco (Nicotiana glutinosa) NPR1-like gene (designated as NgNPR3). The full-length cDNA is 2049 bp in length with a 1767 bp open reading frame which encodes a 588 amino acids protein with an estimated molecular mass of 66 kDa and a calculated pI of 7.14. Homology analysis suggested that the NgNPR3 protein shares significant similarity to AtNPR3 of Arabidopsis. Transient expression assay of NgNPR3-GFP fusion gene in onion epidermal cells revealed that the NgNPR3 protein was localized to the cytoplasm and moved into the nucleus after redox change. RT-PCR results indicated that NgNPR3 was up-regulated after treatment with SA, INA, H(2)O(2,) and MeJA, which play important roles in various resistance responses in tobacco. Transcriptional level of NgNPR3 was also up-regulated after inoculation with Rhizoctonia solani, Phytophthora parasitica, Alternaria alternata, Pseudomonas solanacearum, and potato virus Y (PVY), respectively. When NgNPR3 was overexpressed in N. tabacum cv. Samsun plants, the transgenic plants showed enhanced resistance to the pathogens A. alternate, P. solanacearum and PVY. Furthermore, NgNPR3-mediated disease resistance is dosage-dependent. Our results suggest that NgNPR3 could be a putative NPR1-like gene, and might play an important role in resistance to a broad range of pathogens in tobacco.
Zhang
Y
Y
State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong, China.
Shi
J
J
Liu
J-Y
JY
Zhang
Y
Y
Zhang
J-D
JD
Guo
X-Q
XQ
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics; D002467:Cell Nucleus; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D007113:Immunity, Innate; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism / Q000382:microbiology / Q000821:virology; D018749:RNA, Plant / Q000235:genetics; D016415:Sequence Alignment; D014026:Nicotiana / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology / Q000821:virology; D015854:Up-Regulation
D029681:Arabidopsis Proteins; D018076:DNA, Complementary; C517740:NPR3 protein, Arabidopsis; D010940:Plant Proteins; D018749:RNA, Plant