Regulation of malate synthase (MS) and isocitrate lyase (ICL) gene at the posttranscriptional level was studied using actinomycin D, a transcription inhibitor. Detached roots which contained an abundance of NIS and ICL transcripts due to starvation for 4 days, showed a decrease in mRNA amount of about 50% after 3 h incubation in the presence of 10 ug/mI actinomycin D. In contrast, when sucrose was added together with actinomycin D, MS and ICL mRNA decreased to a much lower level within 3 h. Therefore, NIS and ICL half lives appear much shorter in the presence of sugar. Similar results were obtained with detached cotyledons. Confirmation that actinomycin D had effectively stopped transcription was obtained by showing that it prevented light induced expression of hydroxypyruvate reductase and rubisco genes in cotyledons. Thus, NIS and ICL genes appear to be regulated by sugars at the levels of transcription and mRNA stability.

Item Type:	Refereed Article
Keywords:	malate synthase, isocitrate lyase, mRNA
Research Division:	Biological Sciences
Research Group:	Plant Biology
Research Field:	Plant Physiology
Objective Division:	Expanding Knowledge
Objective Group:	Expanding Knowledge
Objective Field:	Expanding Knowledge in the Biological Sciences
UTAS Author:	Smith, SM (Professor Steven Smith)
ID Code:	101559
Year Published:	2000
Deposited By:	Plant Science
Deposited On:	2015-06-25
Last Modified:	2015-07-08
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