Impaired plant growth and development caused by human immunodeficiency virus type 1 Tat.
Previous attempts to express the human immunodeficiency virus 1 (HIV-1) Tat (trans-activator of transcription) protein in plants resulted in a number of physiological abnormalities, such as stunted growth and absence of seed formation, that could not be explained. In the study reported here, we expressed Tat in tomato and observed phenotypic abnormalities, including stunted growth, absence of root formation, chlorosis, and plant death, as a result of reduced cytokinin levels. These reduced levels were ascribed to a differentially expressed CKO35 in Tat-bombarded tomato. Of the two CKO isoforms that are naturally expressed in tomato, CKO43 and CKO37, only the expression of CKO37 was affected by Tat. Our analysis of the Tat confirmed that the Arg-rich and RGD motifs of Tat have functional relevance in tomato and that independent mutations at these motifs caused inhibition of the differentially expressed CKO isoform and the extracellular secretion of the Tat protein, respectively, in our Tat-bombarded tomato samples.
Cueno
Marni E
ME
Department of Molecular and Cellular Biology Laboratory, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Misuho-cho, Mizuho-ku, Nagoya, Aichi, 467-8601, Japan.
Hibi
Yurina
Y
Imai
Kenichi
K
Laurena
Antonio C
AC
Okamoto
Takashi
T
D020816:Amino Acid Motifs; D002736:Chloroplasts / Q000378:metabolism; D003583:Cytokinins / Q000096:biosynthesis; D004790:Enzyme Induction; D015497:HIV-1 / Q000235:genetics*; D018551:Solanum lycopersicum / Q000235:genetics / Q000254:growth & development*; D008954:Models, Biological; D009842:Oligopeptides / Q000633:toxicity; D010088:Oxidoreductases / Q000096:biosynthesis / Q000235:genetics; D010641:Phenotype; D010935:Plant Diseases / Q000235:genetics; D018517:Plant Roots / Q000648:ultrastructure; D018520:Plant Shoots / Q000648:ultrastructure; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development*; D020033:Protein Isoforms / Q000096:biosynthesis / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000633:toxicity; D013329:Structure-Activity Relationship; D054322:tat Gene Products, Human Immunodeficiency Virus / Q000737:chemistry / Q000235:genetics / Q000633:toxicity*
D003583:Cytokinins; D009842:Oligopeptides; D020033:Protein Isoforms; D011993:Recombinant Fusion Proteins; D054322:tat Gene Products, Human Immunodeficiency Virus; C047981:arginyl-glycyl-aspartic acid; D010088:Oxidoreductases; C019984:cytokinin oxidase