The 5’-region of the chitinase gene cabch29, derived from Brassica oleracea var. capitata, has been sequenced and analyzed for cis-acting elements important in controlling gene expression in transgenic tobacco plants...The 5’-region of the chitinase gene cabch29, derived from Brassica oleracea var. capitata, has been sequenced and analyzed for cis-acting elements important in controlling gene expression in transgenic tobacco plants. Different 5’-deletion fragments were linked to reporter geneβ-glucuronidase (GUS) as translational fusions, and the expression of these chimeric genes was analyzed in vegetative organs and tissues. Sequences up to -651 showed some basal GUS activity with nearly equal levels in wounded and intact tissues. The addition of further upstream sequences (-651 to -1284) enhanced expression level, and the expression driven by this fragment was inducible by a factor of two to three-fold by wounding. Histochemical analysis of different tissue from transgenic plants that contain cabch29 promoter-GUS fusion gene demonstrated woundinducible and tissue-specific cabch29 promoter activity in plants containing the 1308 base pair fragment. The location of GUS activity appears to be cell-specific, being highest in vascular cells and epidermal cells of stem, leaf and roots. Meanwhile, the temporal and spatial expression of cabch29-GUS fusion gene has been investigated. Among the different vegetative organs, a high level of GUS activity was observed in stem and a moderate one in roots;whereas, wounding stress led to a high level of GUS in stem and moderate one in leaf.展开更多
Tomato systemin is a bioactive peptide that regulates the systemic activation of wound-responsive genes. It is released from its 200 amino acid precursor called prosystemin. Initial tissue-localization and hormone-ind...Tomato systemin is a bioactive peptide that regulates the systemic activation of wound-responsive genes. It is released from its 200 amino acid precursor called prosystemin. Initial tissue-localization and hormone-induced expression assays indicated that the tomato prosystemin gene （SIPS） accumulates mainly in floral tissues and in response to exogenous abscisic acid and methyl jasmonate （MeJA） treatments, respectively. Later, the promoter regions of the PS gene in tomato （Solanum lycopersicum L. cv. Castlemart）, pepper （Capsicum annuum） and potato （Solanum tuberosum） were isolated and an in silico analysis of the SIPS promoter revealed an over-representation of stress- and MeJA-responsive motifs. A subsequent 5＇ deletion analysis of the SIPS promoter fused to the/^-glucuronidase reporter （GUS） gene showed that the -221 to ＋40 bp proximal SIPS promoter region was sufficient to direct the stigma, vascular bundle-specific and MeJA-responsive expression of GUS in transgenic tobacco plants. Important vascular.tissue-specific, light- and MeJA-responsive cis-elements were also present in this region. These findings provide relevant information regarding the transcriptional regulation mechanisms of the SIPS promoter operating in transgenic tobacco plants. They also suggest that its Ussue-specificity and inducible nature could have wide applicability in plant biotechnology.展开更多
文摘The 5’-region of the chitinase gene cabch29, derived from Brassica oleracea var. capitata, has been sequenced and analyzed for cis-acting elements important in controlling gene expression in transgenic tobacco plants. Different 5’-deletion fragments were linked to reporter geneβ-glucuronidase (GUS) as translational fusions, and the expression of these chimeric genes was analyzed in vegetative organs and tissues. Sequences up to -651 showed some basal GUS activity with nearly equal levels in wounded and intact tissues. The addition of further upstream sequences (-651 to -1284) enhanced expression level, and the expression driven by this fragment was inducible by a factor of two to three-fold by wounding. Histochemical analysis of different tissue from transgenic plants that contain cabch29 promoter-GUS fusion gene demonstrated woundinducible and tissue-specific cabch29 promoter activity in plants containing the 1308 base pair fragment. The location of GUS activity appears to be cell-specific, being highest in vascular cells and epidermal cells of stem, leaf and roots. Meanwhile, the temporal and spatial expression of cabch29-GUS fusion gene has been investigated. Among the different vegetative organs, a high level of GUS activity was observed in stem and a moderate one in roots;whereas, wounding stress led to a high level of GUS in stem and moderate one in leaf.
基金supported by a doctoral scholarship(191369)granted by The National(CONACyT,México)The State(CONCyTEG-Fondos Mixtos,Guanajuato)Councils of Science and Technology,respectively
文摘Tomato systemin is a bioactive peptide that regulates the systemic activation of wound-responsive genes. It is released from its 200 amino acid precursor called prosystemin. Initial tissue-localization and hormone-induced expression assays indicated that the tomato prosystemin gene （SIPS） accumulates mainly in floral tissues and in response to exogenous abscisic acid and methyl jasmonate （MeJA） treatments, respectively. Later, the promoter regions of the PS gene in tomato （Solanum lycopersicum L. cv. Castlemart）, pepper （Capsicum annuum） and potato （Solanum tuberosum） were isolated and an in silico analysis of the SIPS promoter revealed an over-representation of stress- and MeJA-responsive motifs. A subsequent 5＇ deletion analysis of the SIPS promoter fused to the/^-glucuronidase reporter （GUS） gene showed that the -221 to ＋40 bp proximal SIPS promoter region was sufficient to direct the stigma, vascular bundle-specific and MeJA-responsive expression of GUS in transgenic tobacco plants. Important vascular.tissue-specific, light- and MeJA-responsive cis-elements were also present in this region. These findings provide relevant information regarding the transcriptional regulation mechanisms of the SIPS promoter operating in transgenic tobacco plants. They also suggest that its Ussue-specificity and inducible nature could have wide applicability in plant biotechnology.
