GusPlus Overview

GUSPlus™ is a new reporter gene for use in molecular biology. There are GUSPlus vectors for checking transformations and screening transformants, and special vectors for use with TransBacter strains. The GUSPlus gene was originally isolated from Staphylococcus sp. but has been extensively altered by codon optimisation for expression in plants. It is described in Nature 433:629ff and in patents and patent applications including US patents 6,391,547, 6,641,996, 7,087,420 and 7,141,719. Issued in Australia as Patent Number 760275. Issued in New Zealand as Patent Number 1485. Published as WO 00/055333 and WO 99/13085 and pending in Brazil, Canada, Europe and Israel.

A pCAMBIA GUSPlus kit contains the following plasmids:

pCAMBIA1105.1, pCAMBIA1305.1, pCAMBIA1305.2, pCAMBIA0305.1, pCAMBIA0305.2, pCAMBIA1105.1R and pCAMBIA0105.1R

Detailed Description of GUSPlus

The beta-glucuronidase (GUS) enzyme from E. coli has been widely used to study promoter activity in different tissues or developmental stages. Recombinant DNA constructs are made in which the reporter gene (GUS) is attached to a promoter region of interest and the construct transformed into a cell or organism. However, it has some limitations that are overcome by a second generation of GUS gene developments at CAMBIA, which we are now making available in open source licenses. The GUSPlus gene was originally isolated from Staphylococcus sp. but has been extensively altered by codon optimisation for expression in plants.

Benefits of GUSPlus compared to E.coli GUS:

Greater sensitivity, leading to faster colour development with X-glcA substrate
Can be secreted, allowing non-destructive assay
Higher thermal stability
Greater tolerance to fixatives

CAMBIA has now developed vectors that include GUSPlus.

GUSPlus is a more sensitive reporter gene than E.coli GUS

EcGUS-vs-GUSPlus-graph

GUSPlus can be used to screen for transformed tissue/plants

We have established efficient plant transformation protocols relying on screening transformed tissue using GUSPlus. Previous attempts to use a beta-glucuronidase for non-destructive assays were hampered by the need to use high concentrations or long incubations with X-glcA. The new GUSPlus gene overcomes these problems. Download the X-glcA assay protocol. (info)

Rice and tobacco plant cells expressing secreted GUSPlus can be identified without compromising their regeneration capability.
Arabidopsis seedlings expressing GUSPlus can be identified at the cotyledon stage and grown to mature plants.

Read about some of the new directions in research using these genes.
Why is GUSPlus better? View a presentation on GUSPlus properties (info) that GUSPlus has compared to E.coli GUS
Compare the five different GUSPlus vectors.
View a presentation on the use of GusPlus as a selectable marker (info) for plant transformation.

The initial work on GUSPlus was carried out as a PhD project by Tuan Nyugen and a publication is expected soon. The work is being supported by the Rockefeller Foundation, Horticulture Australia and Monticello Research Australia.