GUS fusions: beta-glucuronidase as a sensitive and versatile gene fusion marker in higher plants.

Abstract

We have used the Escherichia coli beta‐glucuronidase gene (GUS) as a gene fusion marker for analysis of gene expression in transformed plants. Higher plants tested lack intrinsic beta‐glucuronidase activity, thus enhancing the sensitivity with which measurements can be made. We have constructed gene fusions using the cauliflower mosaic virus (CaMV) 35S promoter or the promoter from a gene encoding the small subunit of ribulose bisphosphate carboxylase (rbcS) to direct the expression of beta‐glucuronidase in transformed plants. Expression of GUS can be measured accurately using fluorometric assays of very small amounts of transformed plant tissue. Plants expressing GUS are normal, healthy and fertile. GUS is very stable, and tissue extracts continue to show high levels of GUS activity after prolonged storage. Histochemical analysis has been used to demonstrate the localization of gene activity in cells and tissues of transformed plants.

Nuclear retention of the transcription factor NLP7 orchestrates the early response to nitrate in plants

“…41)) as control. Eighteen hours after transfection, b-glucuronidase and luciferase activity were measured as described previously 42,43 . In short, protoplasts were extracted with a Triton X-100 containing buffer, and enzyme activities were measured using a fluorogenic or a light emitting assays with 4-methyl umbelliferyl glucuronide and luciferin, respectively, as substrate.…”

Genetic transformation of Indian isolate of Lemna minor mediated by Agrobacterium tumefaciens and recovery of transgenic plants

“…The effect of phenolic-acetosyringone (50-100 μM) during cocultivation was also tested. After co-cultivation, nodular calli were washed with sterile distilled water for five to six times, blotted dry on sterile paper towel, and incubated in X-gluc solution at 37°C for histochemical GUS assay (Jefferson et al 1987). For each variable in an experiment, 35 nodular calli, each weighing 0.025 g, were taken and each experiment was repeated thrice.…”

“…The GUS activity was localized histochemically in nodular calli immediately after co-culture with Agrobacterium according to Jefferson et al (1987). Stable GUS activity was checked in the fronds regenerated from the nodular calli co-cultivated with Agrobacterium.…”

The developmental expression of the asparagus intracellular PR protein (AoPR1) gene correlates with sites of phenylpropanoid biosynthesis

“…A minimum of three independent samples were assayed for each tissue sample. Fluorometric and histochemical analysis of GUS activity (Jefferson et aL, 1987) were carried out as described according to the modifications of Topping et aL (1991). Pollen was stained after removal from anthers and washing twice in staining buffer.…”