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Toxicity symptoms caused by high expression of Tet represser in tomato ( Lycopersicon esculentum Mill. L.) are alleviated by tetracycline
Author(s) -
CORLETT J. E.,
MYATT S. C.,
THOMPSON A. J.
Publication year - 1996
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.1996.tb00336.x
Subject(s) - tetr , lycopersicon , photosynthesis , repressor , biology , tetracycline , chlorophyll , shoot , gene , toxicity , phenotype , gene expression , horticulture , botany , dry weight , microbiology and biotechnology , biochemistry , chemistry , organic chemistry , antibiotics
As a first step towards transferring a tetracycline (Tc)‐inducible gene expression system to tomato, we have transformed tomato plants with the Tn 10 ‐encoded tet repressor gene ( tet R). Homozygous transformed plants with high expression of tet R mRNA show a deleterious phenotype, having reduced shoot dry weights and leaf chlorophyll content, an even more marked reduction in root dry weight and leaf size, and altered photosynthetic physiology. It appears that TetR protein exerts its toxicity only when expressed beyond a threshold level and by interacting with a process that is non‐limiting under slow growth conditions. The deleterious phenotype was almost completely reversed by the application of 1 mg dm −3 Tc to plants grown in sand. The possiblity is discussed that TetR causes these symptoms by binding to a specific DNA sequence functioning as a Tet operator. The effect of Tc on growth and physiology in wild‐type plants grown in sand or rockwool is described. Tc at 0.1 mg cm −3 had no effect. Tc at 1 mg dm −3 caused a small reduction in root growth, while 5 and 20 mg dm −3 Tc caused large reductions in growth and photosynthetic parameters.