Reference "Nonsense-Mediated Decay of Mutant waxy mRNA in Rice"

Reference ID

1673

Title

Nonsense-Mediated Decay of Mutant waxy mRNA in Rice

Source

Plant physiology, 2001, vol. 125, pp. 1388-1395

Authors (4)

Isshiki-M	Yamamoto-Y
Satoh-H	Shimamoto-K

Abstract

Two rice (Oryza sativa) waxy mutations of the Japonica background were shown to
contain approximately 20% of the fully spliced mRNA relative to the wild type.
Sequencing analysis of the entire waxy genes of the two mutants revealed the
presence of premature translation termination codons in exon 2 and exon 7. These
results indicated that the lower accumulation of fully spliced RNA in the
mutants was caused by nonsense- mediated decay (NMD), which is an RNA
surveillance system universally found in eukaryotes. It is interesting that
levels of RNA retaining intron 1 were not changed by premature nonsense codons,
suggesting that splicing may be linked with NMD in plants, as previously found
in mammalian cells. Measurements of the half-lives of waxy RNAs in transfected
rice protoplasts indicated that the half-life of waxy RNA with a premature
nonsense codon was 3.3 times shorter than that without a premature nonsense
codon. Because the wild-type waxy transcripts, which are derived from the Wx(b)
gene predominantly distributed among Japonica rice, have been shown to be less
efficiently spliced and their alternative splicing has been documented, we
examined whether these splicing properties influenced the efficiency of NMD.
However, no effects were observed. These results established that NMD occurs in
rice waxy RNA containing a premature nonsense codon.