Reference "A rice dihydrosphingosine C4 hydroxylase (DSH1) gene, which is abundantly expressed in the stigmas, vascular cells and apical meristem, may be involved in fertility"

Reference ID

11676

Title

A rice dihydrosphingosine C4 hydroxylase (DSH1) gene, which is abundantly expressed in the stigmas, vascular cells and apical meristem, may be involved in fertility

Source

Plant & cell physiology, 2007, vol. 48, pp. 1108-1120

Authors (5)

Imamura-T	Kusano-H
Kajigaya-Y	Ichikawa-M
Shimada-H

Abstract

Dihydrosphingosine C4 hydroxylase is a key enzyme in the biosynthesis of
phytosphingosine, a major constituent of sphingolipids in plants and yeasts. The
rice genome contains five homologue genes for dihydrosphingosine C4 hydroxylase,
DSH1-DSH5, whose gene products show high degrees of homology to the yeast
counterpart, SUR2. Among them, expression of DSH1, DSH2 and DSH4 was detected,
and DSH1 and DSH4 complement the yeast sur2 mutation. The DSH1 gene was
specifically and abundantly expressed in vascular bundles and apical meristems.
In particular, very strong expression was detected in the stigmas of flowers.
Repression of DSH1 expression by the antisense gene or RNA interference (RNAi)
resulted in a severe reduction of fertility. In the transformants in which DSH1
expression was suppressed, significantly increased expression of DSH2 was found
in leaves but not in pistils, suggesting that there was tissue-specific
correlation between DSH1 and DSH2 expression. Our results indicate that the
product of DSH1 may be involved in plant viability or reproductive processes,
and that the phenotype of sterility is apparently caused by loss of function of
DSH1 in the stigma. It is also suggested that there is a complex mechanism
controlling the tissue-specific expression of the DSH1 gene.