Tomato prosystemin promoter confers wound-inducible, vascular bundle-specific expression of the β-glucuronidase gene in transgenic tomato plants

Abstract

Tomato (Lycopersicon esculentum Mill. cv. Better Boy) plants were transformed with a fused gene containing a 2.2-kb promoter fragment of the tomato prosystemin gene and the coding region of the bglucuronidase (GUS) reporter gene. The transgenic plants exhibited a low constitutive level of prosystemin-b-glucuronidase gene expression, assayed by histochemical staining and GUS enzyme activity, that was associated in the vascular bundles of leaf main veins, petiolules, petioles and stems. The GUS activity in the vascular bundles in each tissue was increased by wounding and by treatment of the plants with methyl jasmonate, similar to the induction of prosystemin in wild-type plants. The increase in GUS activity in the vascular bundles of leaves in response to wounding correlated with the wound-inducible increase in prosystemin mRNA. Tissue printing, using rabbit anti-serum prepared against prosystemin, con®rmed that inducible prosystemin protein was localized in vascular bundles of petiolules, petioles and stems of wild-type tomato plants. The evidence indicates that the 2.2-kb promoter region of the tomato prosystemin gene contains elements conferring its correct temporal and spatial expression in the vascular bundles of transgenic tomato plants. Abbreviations: GUS = b-glucuronidase; MJ = methyl jasmonate; Prosys-GUS = prosystemin-b-glucuronidase; Correspondence to: C.A. Ryan; Fax: 1 (509) 335 7643; Tel: 1 (509) 335 3304

Hydrogen Peroxide Acts as a Second Messenger for the Induction of Defense Genes in Tomato Plants in Response to Wounding, Systemin, and Methyl Jasmonate

“…Upon wounding of the leaves by herbivores, systemin is released into the vascular system, where it activates the biosynthesis of jasmonic acid in vascular parenchyma cells, upregulating the synthesis of signal pathway genes, including PG. The gene products include prosystemin and some jasmonic acid biosynthetic enzymes, including isoforms of lipoxygenase and AOS, which are known to be synthesized in the vascular bundle cells (Jacinto et al, 1997;Kubigsteltig et al, 1999). PG is likely to be found in the cell walls of the vascular bundles, where H 2 O 2 is localized (Figure 7).…”

Activation of phospholipase PLA2 actvity in Ricinus communis leaves in response to mechanical wounding

“…The term jasmonate is used for the cyclopentanone compound, jasmonic acid (JA), its methyl ester (JAME) and derivatives such as JA amino acid conjugates (Schaller et al, 2005). In tomato, mechanical wounding leads to expression of the prosystemin gene within vascular bundles (Jacinto et al, 1997). This polypeptide is processed into a peptide of 18 amino acid residues, called systemin (Pearce et al, 2002), which is released into the apoplast from damaged cells and transported through the phloem to distal leaves.…”

Translocation in Legumes: Assimilates, Nutrients, and Signaling Molecules1

“…Phloem mobility was supported by 14 C-labeling studies and more or less specific expression of its precursor protein, prosystemin, in phloem parenchyma (Jacinto et al, 1997). Immunochemical analysis has also located prosystemin in the cytosol of vascular parenchyma cells (Narvaez-Vasquez and Ryan, 2004).…”