The tobacco ubiquitin-activating enzymes NtE1A and NtE1B are induced by tobacco mosaic virus, wounding and stress hormones.
Recent characterization of several genes involved in plant defense responses suggested that ubiquitin-mediated protein degradation has a role in these responses. We isolated two cDNAs (NtUBA1 and NtUBA2) encoding ubiquitin-activating enzyme (E1) from Nicotiana tabacum cv. BY-2. The open reading frames of both encoded 1080 amino acids, corresponding to molecular masses of 120 kDa. The E1s and corresponding transcripts were upregulated by infection with tobacco mosaic virus (TMV) and tomato mosaic virus (ToMV), and to a lesser extent by cucumber mosaic virus (CMV). Furthermore, they were also upregulated by wounding stress, and the plant hormones salicylic acid, jasmonic acid and the ethylene precursor, aminocyclopropane-1-carboxylic acid (ACC). Our findings support the idea that the ubiquitin-proteasome system plays a role in plant disease defenses.
Takizawa
Mari
M
Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan.
Goto
Akiko
A
Watanabe
Yuichiro
Y
D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D017799:Cucumovirus / Q000472:pathogenicity; D003587:Cytomegalovirus / Q000472:pathogenicity; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010935:Plant Diseases / Q000235:genetics / Q000821:virology*; D010937:Plant Growth Regulators / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D014026:Nicotiana / Q000201:enzymology* / Q000235:genetics / Q000821:virology*; D014027:Tobacco Mosaic Virus / Q000472:pathogenicity*; D044764:Ubiquitin-Activating Enzymes / Q000235:genetics / Q000378:metabolism*; D014947:Wounds and Injuries
D018076:DNA, Complementary; D010937:Plant Growth Regulators; D010940:Plant Proteins; D044764:Ubiquitin-Activating Enzymes