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Novel anther-specific myb genes from tobacco as putative regulators of phenylalanine ammonia-lyase expression
- Source :
- Plant physiology. 126(4)
- Publication Year :
- 2001
-
Abstract
- Two cDNA clones (NtmybAS1 andNtmybAS2) encoding MYB-related proteins with strong sequence similarity to petunia (Petunia hybrida) PhMYB3 were isolated from a tobacco (Nicotiana tabacumcv Samsun) pollen cDNA library. Northern blot and in situ hybridization revealed that NtmybAS transcripts are specifically expressed in both sporophytic and gametophytic tissues of the anther including tapetum, stomium, vascular tissue, and developing pollen. Random binding site selection assays revealed that NtMYBAS1 bound to DNA sequences closely resembling consensus MYB binding sites MBSI and MBSIIG, with a higher affinity for MBSI. Transient expression analyses of the N-terminal MYB domain demonstrated the presence of functional nuclear localization signals, and full-length NtMYBAS1 was able to activate two different phenylalanine ammonia-lyase promoters (PALA and gPAL1) in tobacco leaf protoplasts. Similar analysis of truncated NtmybAS1cDNAs identified an essential, C-terminal trans-activation domain. Further in situ hybridization analyses demonstrated strict co-expression of NtmybAS and gPAL1 in the tapetum and stomium. Despite abundant expression ofNtmybAS transcripts in mature pollen,gPAL1 transcripts were not detectable in pollen. Our data demonstrate that NtMYBAS1 is a functional anther-specific transcription factor, which is likely to be a positive regulator ofgPAL1 expression and phenylpropanoid synthesis in sporophytic, but not in gametophytic, tissues of the anther.
- Subjects :
- DNA, Complementary
DNA, Plant
Physiology
Nicotiana tabacum
Molecular Sequence Data
Plant Science
Biology
Petunia
Complementary DNA
Gene expression
Tobacco
Genetics
Animals
Humans
MYB
Northern blot
Amino Acid Sequence
Cloning, Molecular
Phenylalanine Ammonia-Lyase
Plant Proteins
Tapetum
Phenylpropionates
Plant Stems
Sequence Homology, Amino Acid
cDNA library
Reproduction
food and beverages
biology.organism_classification
Molecular biology
Plants, Toxic
Multigene Family
Pollen
Transcription Factors
Research Article
Subjects
Details
- ISSN :
- 00320889
- Volume :
- 126
- Issue :
- 4
- Database :
- OpenAIRE
- Journal :
- Plant physiology
- Accession number :
- edsair.doi.dedup.....8b42187080fb082ae02f3f72b332ec7f