Reference "A cereal haemoglobin gene is expressed in seed and root tissues under anaerobic conditions"

Reference ID

8647

Title

A cereal haemoglobin gene is expressed in seed and root tissues under anaerobic conditions

Source

Plant molecular biology, 1994, vol. 24, pp. 853-862

Authors (4)

Taylor-E-R	Nie-X-Z
MacGregor-A-W	Hill-R-D

Abstract

Legumes, and a very few non-legume plant species, are known to possess
functioning haemoglobin genes. We describe here the characterization of a
haemoglobin cDNA isolated from barley. The deduced amino acid sequence shows 71%
amino acid identity with a non-legume haemoglobin gene, a further 16% of the
residues being conservative replacements. The barley cDNA also hybridizes to
genomic sequences in rye, maize and wheat. The demonstration of a gene from a
monocotyledon with close sequence homology to the known non-legume plant
haemoglobins fills a major gap in the known distribution of haemoglobin genes in
the plant kingdom. The expression of the gene is induced in isolated barley
aleurone layers exposed to anaerobic conditions, and the roots of flooding-
stressed barley plants. The expression of the RNA under anoxic conditions is
similar to that of a known anaerobic response gene, alcohol dehydrogenase. Our
results suggest that the increased expression of haemoglobin RNA is an integral
part of the normal anaerobic response in barley. The findings are discussed in
the light of current theories of haemoglobin function and evolution.