The nfc102 gene encodes a WD-repeat protein belonging to the Multicopy suppressor of IRA (MSI) family, originally identified in yeast. In maize, five genes of the MSI family have been identified and named nfc, because they display homology with one of the NURF complex component, where NURF is the Nucleosome Remodeling Factor: a multi-proteins complex that regulates transcription by catalyzing nucleosome sliding. Among the members of the MSI family, the maize nfc102 gene displays high sequence homology with the Arabidopsis FVE, which is a component of the autonomous flowering pathway and that regulates transposons transcription. Although FVE is known as a positive flowering regulator, mainly because it inhibits expression of the flowering repressor locus FLC, it has been recently shown that FVE can also negatively affect transcription of the Arabidopsis florigen FT. In all cases, FVE acts by affecting histone modification pattern, thus provoking changes in the chromatin structure of its targets. In maize, up to now none of the several members of the MADS-box transcription factor class exhibit a functional homology with the Arabidopsis FLC. However, the homolog of the Arabidopsis FT gene has been recently identified and named ZCN8. FT othologs from different plant species were shown to behave as a flower-forming signal because they were transcribed and translated in leaves, but their proteins subsequently move through the phloem to the SAM, where they induced the floral transition upon reaching a critical concentration. Interestingly, ZCN8 RNA is detected almost exclusively in an unspliced form in tissues enriched for meristematic area (MA), while the spliced RNA form is formed only in leave blades (LB). Using strand specific RT-PCR we have observed that the unspliced ZCN8 RNA form is mainly represented by the antisense ZCN8 RNA strand. A shorter antisense ZCN8 RNA strand was also detected, corresponding to a spliced RNA that lacks the first exon and a part of the first intron. The ZCN8 sense RNA strand was almost exclusively present in LB as a fully spliced form. Analysis of the ZCN8 sense and antisense RNA levels in nfc102 RNAi mutant compared to wild-type plants showed that nfc102 down-regulation affect the ratio between the unspliced versus the spliced form of ZCN8 sense and antisense transcripts. In this poster we will illustrate in details these findings and we will discuss about the possible role of nfc102 in controlling ZCN8 expression by linking changes in chromatin structure with RNA processing.
THE MAIZE WD-REPEAT CHROMATIN REMODELING GENE nfc102 REGULATES THE MAIZE HOMOLOG OF THE ARABIDOPSIS FLORIGEN FT
MAINIERI D;
2011
Abstract
The nfc102 gene encodes a WD-repeat protein belonging to the Multicopy suppressor of IRA (MSI) family, originally identified in yeast. In maize, five genes of the MSI family have been identified and named nfc, because they display homology with one of the NURF complex component, where NURF is the Nucleosome Remodeling Factor: a multi-proteins complex that regulates transcription by catalyzing nucleosome sliding. Among the members of the MSI family, the maize nfc102 gene displays high sequence homology with the Arabidopsis FVE, which is a component of the autonomous flowering pathway and that regulates transposons transcription. Although FVE is known as a positive flowering regulator, mainly because it inhibits expression of the flowering repressor locus FLC, it has been recently shown that FVE can also negatively affect transcription of the Arabidopsis florigen FT. In all cases, FVE acts by affecting histone modification pattern, thus provoking changes in the chromatin structure of its targets. In maize, up to now none of the several members of the MADS-box transcription factor class exhibit a functional homology with the Arabidopsis FLC. However, the homolog of the Arabidopsis FT gene has been recently identified and named ZCN8. FT othologs from different plant species were shown to behave as a flower-forming signal because they were transcribed and translated in leaves, but their proteins subsequently move through the phloem to the SAM, where they induced the floral transition upon reaching a critical concentration. Interestingly, ZCN8 RNA is detected almost exclusively in an unspliced form in tissues enriched for meristematic area (MA), while the spliced RNA form is formed only in leave blades (LB). Using strand specific RT-PCR we have observed that the unspliced ZCN8 RNA form is mainly represented by the antisense ZCN8 RNA strand. A shorter antisense ZCN8 RNA strand was also detected, corresponding to a spliced RNA that lacks the first exon and a part of the first intron. The ZCN8 sense RNA strand was almost exclusively present in LB as a fully spliced form. Analysis of the ZCN8 sense and antisense RNA levels in nfc102 RNAi mutant compared to wild-type plants showed that nfc102 down-regulation affect the ratio between the unspliced versus the spliced form of ZCN8 sense and antisense transcripts. In this poster we will illustrate in details these findings and we will discuss about the possible role of nfc102 in controlling ZCN8 expression by linking changes in chromatin structure with RNA processing.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
