Tomato transcription factors pti4, pti5, and pti6 activate defense responses when expressed in Arabidopsis.
The Pti4, Pti5, and Pti6 proteins from tomato were identified based on their interaction with the product of the Pto disease resistance gene, a Ser-Thr protein kinase. They belong to the ethylene-response factor (ERF) family of plant-unique transcription factors and bind specifically to the GCC-box cis element present in the promoters of many pathogenesis-related (PR) genes. Here, we show that these tomato ERFs are localized to the nucleus and function in vivo as transcription activators that regulate the expression of GCC box-containing PR genes. Expression of Pti4, Pti5, or Pti6 in Arabidopsis activated the expression of the salicylic acid-regulated genes PR1 and PR2. Expression of jasmonic acid- and ethylene-regulated genes, such as PR3, PR4, PDF1.2, and Thi2.1, was affected differently by each of the three tomato ERFs, with Arabidopsis-Pti4 plants having very high levels of PDF1.2 transcripts. Exogenous application of salicylic acid to Arabidopsis-Pti4 plants suppressed the increased expression of PDF1.2 but further stimulated PR1 expression. Arabidopsis plants expressing Pti4 displayed increased resistance to the fungal pathogen Erysiphe orontii and increased tolerance to the bacterial pathogen Pseudomonas syringae pv tomato. These results indicate that Pti4, Pti5, and Pti6 activate the expression of a wide array of PR genes and play important and distinct roles in plant defense.
Gu
Yong-Qiang
YQ
Boyce Thompson Institute for Plant Research, Ithaca, New York 14853, USA.
Wildermuth
Mary C
MC
Chakravarthy
Suma
S
Loh
Ying-Tsu
YT
Yang
Caimei
C
He
Xiaohua
X
Han
Yu
Y
Martin
Gregory B
GB
D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics; D001203:Ascomycota / Q000254:growth & development; D002467:Cell Nucleus / Q000235:genetics; D003517:Cyclopentanes / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000235:genetics; D023082:Defensins; D005030:Ethylenes / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D007113:Immunity, Innate / Q000235:genetics; D018551:Solanum lycopersicum / Q000235:genetics*; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics; D054883:Oxylipins; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D011549:Pseudomonas / Q000254:growth & development; D011956:Receptors, Cell Surface / Q000235:genetics; D020156:Salicylic Acid / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics*; D015533:Transcriptional Activation / Q000235:genetics
D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D004268:DNA-Binding Proteins; D023082:Defensins; C119963:EIN2 protein, Arabidopsis; D005030:Ethylenes; D009687:Nuclear Proteins; D054883:Oxylipins; D010940:Plant Proteins; C106895:Pti4 protein, Lycopersicon esculentum; C106896:Pti5 protein, Lycopersicon esculentum; C106897:Pti6 protein, Lycopersicon esculentum; D011956:Receptors, Cell Surface; D014157:Transcription Factors; C093680:ethylene-responsive element binding protein; C011006:jasmonic acid; C036216:ethylene; C084354:Pto protein, Lycopersicon; D017346:Protein Serine-Threonine Kinases; D020156:Salicylic Acid