We describe the isolation of the Le gene of pea, which controls internode elongation and originally was described by Mendel. Heterologous screening of a pea cDNA library yielded a partial clone that was 61% identical to coding regions of the putative Arabidopsis gibberellin 3β-hydroxylase gene, GA4. DNA gel blot analysis with this cDNA revealed a HindIII restriction fragment length polymorphism between pea isolines differing at Mendel's Le locus. Genomic clones of the GA4-related gene were isolated from the Le and le isolines. Polymerase chain reaction combined with restriction fragment length polymorphism analysis were used to show that the gene mapped to the Le locus. A cDNA containing a complete open reading frame of the pea GA4-related gene was amplified by polymerase chain reaction from each isoline. Recombinant expression in Escherichia coil demonstrated that the product of the Le cDNA was a gibberellin 3β-hydroxylase that is able to convert GA 20 to the bioactive GA 1. Substantially reduced levels of gibberellin 3β-hydroxylase activity were measured, after expression of the le cDNA, by using identical methods. This reduced activity was associated with an alanine-to-threonine substitution in the predicted amino acid sequence of the enzyme near its proposed active site.

Item Type:	Refereed Article
Research Division:	Biological Sciences
Research Group:	Biochemistry and cell biology
Research Field:	Cell metabolism
Objective Division:	Expanding Knowledge
Objective Group:	Expanding knowledge
Objective Field:	Expanding knowledge in the environmental sciences
UTAS Author:	Lester, DR (Dr Diane Lester)
UTAS Author:	Ross, JJ (Associate Professor John Ross)
UTAS Author:	Davies, PJ (Dr Davies)
UTAS Author:	Reid, JB (Professor Jim Reid)
ID Code:	10350
Year Published:	1997
Web of Science® Times Cited:	163
Deposited By:	Plant Science
Deposited On:	1997-08-01
Last Modified:	2012-07-30
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