Project description:Arabidopsis, when grown under short day conditions (16 hours dark, 8 hours light, 22oC) develop extensive secondary thickened hypocotyls with both a vascular and cork cambium (Chaffey et al, 2002, Phys. Plant., 114:594-600). It has been found that once secondary xylem development is completed within the Arabidopsis hypocotyls, it closely resembles the structure of the wood of angiosperm trees (Chaffey et al, 2002, Phys. Plant., 114:594-600). We can utilise this model Arabidopsis tree to identify genes that are important for secondary cell wall formation in xylem cells and therefore important for wood development. Columbia plants were grown for 3 months under short day conditions and secondary thickened hypocotyls were snap-frozen in liquid nitrogen. RNA was isolated from these hypocotyls and submitted to NASC for probing against the ATH1-121501 full GeneChip. Keywords: growth_condition_design
Project description:Transcriptional profiling of diploid and tetraploid Arabidopsis dark-grown hypocotyls. The aim of this study was to identify ploidy-related genes involved in the determination of cell size. This study showed that a group of genes involved in lipid transport/localization/binding were downregulated in a defined region of the tetraploid hypocotyl when compared to the diploid hypocotyl.
Project description:Arabidopsis, when grown under short day conditions (16 hours dark, 8 hours light, 22oC) develop extensive secondary thickened hypocotyls with both a vascular and cork cambium (Chaffey et al, 2002, Phys. Plant., 114:594-600). It has been found that once secondary xylem development is completed within the Arabidopsis hypocotyls, it closely resembles the structure of the wood of angiosperm trees (Chaffey et al, 2002, Phys. Plant., 114:594-600). We can utilise this model Arabidopsis tree to identify genes that are important for secondary cell wall formation in xylem cells and therefore important for wood development. Columbia plants were grown for 3 months under short day conditions and secondary thickened hypocotyls were snap-frozen in liquid nitrogen. RNA was isolated from these hypocotyls and submitted to NASC for probing against the ATH1-121501 full GeneChip.
Project description:Arabidopsis, when grown under short day conditions (16 hours dark, 8 hours light, 22oC) develop extensive secondary thickened hypocotyls with both a vascular and cork cambium (Chaffey et al, 2002, Phys. Plant., 114:594-600). It has been found that once secondary xylem development is completed within the Arabidopsis hypocotyls, it closely resembles the structure of the wood of angiosperm trees (Chaffey et al, 2002, Phys. Plant., 114:594-600). We can utilise this model Arabidopsis tree to identify genes that are important for secondary cell wall formation in xylem cells and therefore important for wood development. Columbia plants were grown for 3 months under short day conditions and secondary thickened hypocotyls were snap-frozen in liquid nitrogen. RNA was isolated from these hypocotyls and submitted to NASC for probing against the ATH1-121501 full GeneChip. Experiment Overall Design: 2 samples
Project description:Driven by cell elongation, hypocotyl growth is tightly controlled by light and responds to both external stimuli and endogenous hormonal pathways. Hypocotyls are responsive to the stress signalling hormone abscisic acid (ABA), which effectively inhibits cell elongation. However, how this regulation is connected to light signalling has been a subject of limited studies. Here, we show that, contrary to light-grown seedlings, hypocotyl elongation of dark-grown seedlings is ABA-insensitive. In the dark, hypocotyl sensitivity to ABA is restored in the constitutive photomorphogenic pifq and cop1-4 mutants, suggesting that an active light signalling pathway is necessary for hypocotyl responsiveness to ABA. Surprisingly, etiolated hypocotyls retain an intact ABA signalling pathway, as could be detected by the induction of ABI1 and RD29B transcripts in response to exogenous ABA, suggesting that inhibition of hypocotyl elongation occurs through a divergent path that can be inhibited by PIFs. Here, using RNA-seq analysis we identified a number of ABA differentially expressed genes (DEGs) that correlate with ABA inhibition of hypocotyl elongation. Among these DEGs a number of SMALL AUXIN-UP RNA (SAUR) genes that are known to directly repress D-CLADE TYPE 2C PROTEIN PHOSPHATASES (PP2C.D) were found. The abrogation of PP2CD.D2-SAUR interaction in the pp2c.d2/PP2C.D2M331K -GFP line, restored ABA sensitivity in the dark, suggesting that SAUR proteins, upregulated by PIFs, are sufficient to render hypocotyls insensitive to ABA. This hypocotyl-specific mechanism enables to promote growth towards the light at all costs, overriding ABA inhibition of cell elongation, to ensure subsequent seedling establishment and survival.