Functional identification and regulation of the PtDrl02 gene promoter from triploid white poplar.
The PtDrl02 gene belongs to the TIR-NBS gene family in triploid white poplar (Populus tomentosa x P. bolleana) x P. tomentosa. Its expression pattern displays tissue-specificity, and the transcript level can be induced by wounding, methyl jasmonate (MeJA), and salicylic acid (SA). To understand the regulatory mechanism controlling PtDrl02 gene expression, we functionally characterized the PtDrl02 promoter region. Using the beta-glucuronidase as a reporter, we found that the PtDrl02 promoter directed gene expression mainly in the aerial parts of the plants and was confined to the cortex tissues of leaf veins, petioles, stems, and stem piths, showing a typical tissue-specific expression pattern. Deletion analysis revealed two positive regulatory regions (-985 to -669 and -669 to -467) responsible for the basal activity of the PtDrl02 promoter. Impressively, the sequence from -669 to -467 was shown to contain cis-element (s) responding to wounding and MeJA, while the promoter region between -244 and 0 could individually display wounding-responsiveness, and the fragment from -467 to -244 was required for SA- and NaCl-inducible expression of the PtDrl02 promoter. Additionally, it was found that the -985 to -669 sequence was the ABA-responding promoter fragment. These results suggested that the PtDrl02 promoter was modulated by multiple cis-regulatory elements in distinct and complex patterns to regulate PtDrl02 gene expression. Our study also suggested that the PtDrl02 gene 5' untranslated region, as well as a Populus WRKY transcription factor, PtWRKY1, was involved in the regulation of PtDrl02 promoter activities.
Zheng
Huiquan
H
National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, Beijing Forestry University, Beijing, People's Republic of China.
Lin
Shanzhi
S
Zhang
Qian
Q
Lei
Yang
Y
Hou
Lu
L
Zhang
Zhiyi
Z
D000085:Acetates / Q000494:pharmacology; D003517:Cyclopentanes / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D017930:Genes, Reporter; D054883:Oxylipins / Q000494:pharmacology; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D032107:Populus / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D018749:RNA, Plant / Q000235:genetics; D020156:Salicylic Acid / Q000494:pharmacology; D012965:Sodium Chloride / Q000494:pharmacology; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D014170:Transformation, Genetic
D000085:Acetates; D003517:Cyclopentanes; D054883:Oxylipins; D018749:RNA, Plant; D014157:Transcription Factors; D012965:Sodium Chloride; C072239:methyl jasmonate; D020156:Salicylic Acid