Alternative splicing and expression analysis ofOsFCA(FCAinOryza sativaL.), a gene homologous toFCAinArabidopsis

Abstract

A subtracted cDNAs library was constructed using rice (Oryza sativa L.) calli cDNA as driver and differentiating calli cDNA as tester. A novel gene homologous with FCA in Arabidopsis was cloned from rice by screening the SSH (suppression subtractive hybridization) library followed by RACE. Four alternative transcripts of OsFCA were cloned from the leaves of rice, and designated as OsFCA-1, OsFCA-2, OsFCA-3 and OsFCA-4 respectively. OsFCA-1 was homologous to FCA-gamma of Arabidopsis and contained several conserved domains (two RNA Recognition Motifs and one WW-domain). OsFCA-2 was 102 bp shorter than OsFCA-1 which caused the WW-domain deletion. The proteins encoded by OsFCA-3 and OsFCA-4 were 101 amino acids shorter than OsFCA-1 at the N-terminal which is a glycine-rich region. The fluorescence quantitative PCR analysis showed that the mRNA of OsFCA-1 is the most abundant in the four splicing variants of rice FCA, and its expression level is much higher in differentiating calli than in calli. The expression of OsFCA-1 is steady in the leaves of three different stage, but up-regulated in young spikelet of primary branch-differentiating stage and down-regulated in young spikelet of pistil and stamen-differentiating stage.

OsFCA Transcripts Show More Complex Alternative Processing Patterns than its Arabidopsis Counterparts

“…These transcripts were detected in all of the tissue types tested; however, both had lower expression levels in roots. These results are similar to the relative expression levels of the indica-type OsFCA transcripts found in the leaves and spikelets of Chinese hybrid rice lines (Du et al 2006). The expression of OsFCA-δ remained unaltered during the panicle developmental stages.…”

“…Since the relative amount of OsFCA transcripts (α, β, γ, δ) was already known (Du et al 2006;Lee et. al.…”

“…Some other alternatively processed OsFCA transcripts have also been identified in indica-type rice (Du et al 2006;Lee et al 2005;Winichayakul et al 2005). In order to determine whether these indica-type OsFCA transcripts also exist in japonica-type rice, we performed RT-PCR using primers designed to detect the specific regions of the transcripts (Figs.…”

“…We also noticed that several indica-type rice mRNAs (rFCA-1, -2, -3, and -4), which were similar to the OsFCA transcripts, were in the public sequence database (Lee et al 2005). These indica-type rice transcripts were later renamed as OsFCA-1, -2, -3, and -4 (Du et al 2006). The OsFCA-1 mRNA (accession no.…”

Overexpression of the rFCA RNA Recognition Motif Affects Morphologies Modifications in Rice (Oryza sativa L.)

“…FCA RRM domains are known to mediate RNA-binding functions in a large number of different proteins. The rice FCA gene was homologous to FCA-gamma of Arabidopsis and contained conserved domains (two RNA-binding domains and a WW-domain) (Du et al 2006). We want to provide phenotypic evidence that the two consensus RNA-binding motifs of rFCA are functional in rice.…”