AtSAGT1 encodes a salicylic acid (SA) glucosyltransferase enzyme that catalyzes the formation of SA glucoside and SA glucose ester. Here, the AtSAGT1 gene expression patterns were determined in AtSAGT1 promoter::GUS transgenic Arabidopsis plants. As a result, the factors regulating the induction of AtSAGT1 were identified as pathogen defense response, wound response, exogenous application of SA, and jasmonic acid treatment.

Perennial ryegrass (Lolium perenne L.) is one of the most important grass species in the world's temperate zones. It is used as high-quality forage in pastures and for recreational use as turf in golf courses, lawns and parks. Genetic improvement of perennial ryegrass is difficult due to its self-incompatibility. Consequently, progress by conventional breeding can be slow. Genetic transformation is an alternative that permits direct introduction of useful genes into a plant's genome and is becoming a powerful tool to complement conventional breeding. To improve environmental stress tolerance and quality of perennial ryegrass by introducing better and useful genes into the genome, we have developed a rapid and efficient transformation system using Agrobacterium-mediated gene transfer system.

Carotenoid isomerase (CRTISO) catalyzes the isomerization of prolycopene to all-trans-lycopene in the carotenoid biosynthetic pathway. We isolated a full-length promoter region of CuCRTISO from Citrus unshiu. We determined if the promoter encoded organ-specific or developmental-specific expression, and identified possible cis-acting promoter elements. The full-length promoter and two truncated versions were fused to the β-glucuronidase (GUS) gene and transformed into Arabidopsis thaliana. Transgenic lines expressing the full-length promoter (pCiso-Prom1) and truncated promoters (pCiso-Prom2 and pCiso-Prom3) showed the same developmental and organ-specific activity. GUS expression was detected in the cotyledon and root at 5 and 10 days after germination, mature leaf, and anther. The CuCRTISO promoter contained several cis-acting elements involved in hormonal and environmental stress. Drought stress or abscisic acid treatment did not induce GUS expression in any transgenic lines. Heat stress induced GUS expression in the pCiso-Prom1 line; this promoter construct contains the heat-stress responsive element (HSE). Ethylene and cold-stress treatments induced GUS expression only in the pCiso-Prom3 line, although all transgenic lines contained the same cis-acting ethylene and low-temperature response elements. which could indicate the existence of unknown repressor element(s) in the CuCRTISO promoter. These studies indicate that CuCRTISO promoter activity is regulated in a developmental and organ-specific manner that responds to heat, cold, and ethylene. These results provide new insights into the role of cis-acting element(s) in CuCRTISO promoter activity. (This research was supported by the Basic Science Research Program of the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2010-0007627 and 2009-0094059), and by Golden Seed Project, Ministry of Agriculture, Food and Rural Affairs (MAFRA), Ministry of Oceans and Fisheries (MOF), Rural Development Administration (RDA) and Korea Forest Service (KFS), Republic of Korea)

Transient expression profiles for several chimeric β-glucuronidase (GUS) gene constructs were determined in microspore-derived embryos of wheat following microprojectile bombardment. The constructs analyzed consisted of the uidA (GUS) reporter gene driven by six different promoters [Cauliflower Mosaic Virus 35S (CaMV35S), Nopaline synthase (NOS), Mannopine synthase (MAS), Chlorella Mosaic Virus Adenin methyltransferase (AMT), maize Ubiquitin 1 (UBI1), and enhanced 35S (E35S)]. The total numbers of GUS blue spot were determined manually under a dissecting microscope after histochemical staining for GUS. Results suggest that the E35S promoter is the most active and UBI1 promoter is the second active in embryos or embryogenic calli derived from wheat microspore. In addition, by flurometric assay on GUS, the E35S promoter was the best. Therefore, both UBI1 and E35S promoter are suitable for constitutive expression of the gene of interest in microspore-derived embryos of wheat. This information describing promoter functionality in wheat will be important when designing gene constructs for traits modification and when choosing appropriate cultivars for improvement through gene transfer experiments.

The effect of osmotic condition on β-glucuronidase (GUS) transient expression was evaluated in microspore-derived embryos of wheat. Microspore explants were treated on medium containing various mannitol concentrations prior to and post bombardment with plasmid DNA pAHC25 containing uidA gene controlled by maize ubiquitin 1 (UBI1) promoter. GUS expression in the bombarded explants was examined by histochemical and fluorometric assays. Increased GUS expression was observed with mannitol treatment when compared to untreated explants. The histochemical study showed that the number of blue (GUS) foci were the highest in the bombarded explants treated with 0.6 M mannitol medium. The fluorometric assay of bombarded explants also proved 3.5-fold increase in GUS activity with 0.6 M mannitol treatment when compared to without mannitol treatment. These results indicate that 0.6 M mannitol is beneficial for improving transformation efficiency of wheat microspore-derived embryos or embryogenic calli through biolistic transformation.