PSARK::IPT transgenic cotton plants produced more root and shoot biomass, dropped fewer flowers, maintained higher chlorophyll content, and higher photosynthetic rates under reduced irrigation conditions in comparison to wild-type and segregated non-transgenic lines. 

Furthermore, PSARK::IPT-transgenic cotton plants grown in growth chamber condition also displayed greater drought tolerance.  These results indicate that water-deficit induced expression of an isopentenyltransferase gene in cotton could significantly improve drought tolerance.

TLS Online TPP Program

#Id: 2646

#Unit 13. Methods in Biology

A G-less cassette, or stretch of nucleotides lacking guanines in the nontemplate strand, is inserted just downstream of the promoter. This template is transcribed in vitro with CTP, ATP, and UTP, one of which is labeled, but no GTP.

TLS Online TPP Program

#Id: 2647

#Unit 13. Methods in Biology

In G-less cassette, transcription will stop at the end of the cassette where the first G is required, yielding an aborted transcript of predictable size (based on the size of the G-less cassette, which is usually a few hundred base pairs long).

TLS Online TPP Program

#Id: 2648

#Unit 13. Methods in Biology

Primer extension, S1 mapping, and Northern blotting are useful for determining the concentrations of specific transcripts in a cell at a given time, but they do not necessarily tell us the rates of synthesis of the transcripts.

TLS Online TPP Program

#Id: 2735

#Unit 13. Methods in Biology

In Run-on transcription- the RNA polymerase that has already initiated transcription in vivo simply “runs on” or continues to elongate the same RNA chains. 

TLS Online TPP Program

#Id: 2736

#Unit 13. Methods in Biology

The run-on reaction is usually done in the presence of labeled nucleotides so the products will be labeled.

TLS Online TPP Program

#Id: 2737

#Unit 13. Methods in Biology

Nuclear run-on transcription is a way of ascertaining which genes are active in a given cell by allowing transcription of these genes to continue in isolated nuclei.