Reference "Gene cloning and expression of cytosolic glutathione reductase in rice (Oryza sativa L.)"

Reference ID

1866

Title

Gene cloning and expression of cytosolic glutathione reductase in rice (Oryza sativa L.)

Source

Plant & cell physiology, 1998, vol. 39, pp. 1269-1280

Authors (5)

Kaminaka-H	Morita-S
Nakajima-M	Masumura-T
Tanaka-K

Abstract

We have isolated a cDNA (RGRC2) encoding glutathione reductase (GR) from rice
(Oryza sativa L.). The comparison of deduced amino acid sequences from RGRC2 and
other plant GR cDNAs indicated that RGRC2 encodes a putative cytosolic isoform.
The recombinant RGRC2 protein had enzymatic properties comparable to those of GR
from rice embryo. Subcellular fractionation showed that the RGRC2 protein is
localized primarily in cytosol. mRNA and protein of RGRC2 were observed mainly
in roots and calli but little in leaf tissues. Southern blot analysis showed
that the RGRC2 gene exists as a single copy gene. Here, we have also isolated a
genomic clone completely corresponding to RGRC2. The RGRC2 gene is split into 16
exons spread about 7.4 kb of chromosomal DNA, with coding sequence beginning in
the 2nd exon and ending in the 16th exon. From the presence of two ABA-
responsive elements in the 5'- flanking region of RGRC2, we examined the
expression in rice seedlings treated with ABA and the ABA-related environmental
stresses, chilling, drought and salinity. The expression of RGRC2 was strongly
induced by all these treatments. We suggest that the expression of the rice
cytosolic GR gene is regulated via ABA-mediated signal transduction pathway
under environmental stresses.