Osmotic stress tolerance of transgenic tobacco expressing a gene encoding a membrane-located receptor-like protein from tobacco plants.
Tobacco (Nicotiana tabacum) genes regulated during the early stage of responses to wounding were screened by a modified fluorescence differential display method. Among 28 genes initially identified, a particular clone designated NtC7 was subjected to further analysis. Its transcripts were found to accumulate rapidly and transiently within 1 h upon treatments with not only wounding but also salt and osmotic stresses. However, jasmonic and abscisic acids and ethylene did not effectively induce NtC7 transcripts. Amino acid sequence analysis suggested NtC7 to be a new type of transmembrane protein that belongs to the receptor-like protein family, and a membrane location was confirmed in onion (Allium cepa) epidermis cells transiently expressing an NtC7-green fluorescent protein fusion protein. Seeds of transgenic tobacco overexpressing NtC7 normally germinated and grew in the presence of 500 mM mannitol, but not in the presence of 220 mM sodium chloride or 60 mM lithium chloride. Cuttings of mature transgenic leaf exhibited a marked tolerance upon treatment with 500 mM mannitol for 12 h, at which concentration wild-type counterparts were seriously damaged. These results suggested that NtC7 predominantly functions in maintenance of osmotic adjustment independently of ion homeostasis.
Tamura
Takashi
T
Research and Education Center for Genetic Information, Nara Institute of Science and Technology, Nara 630-0192, Japan.
Hara
Kojiro
K
Yamaguchi
Yube
Y
Koizumi
Nozomu
N
Sano
Hiroshi
H
D000222:Adaptation, Physiological / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D000595:Amino Acid Sequence; D001483:Base Sequence; D018506:Gene Expression Regulation, Plant; D049452:Green Fluorescent Proteins; D018021:Lithium Chloride / Q000494:pharmacology; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008353:Mannitol / Q000494:pharmacology; D008969:Molecular Sequence Data; D009997:Osmotic Pressure / Q000187:drug effects; D010937:Plant Growth Regulators / Q000494:pharmacology; D018515:Plant Leaves / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012965:Sodium Chloride / Q000494:pharmacology; D013314:Stress, Mechanical; D014026:Nicotiana / Q000187:drug effects / Q000235:genetics / Q000502:physiology*
D008164:Luminescent Proteins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D008353:Mannitol; D012965:Sodium Chloride; D018021:Lithium Chloride