Project description:Injured plant somatic tissues regenerate themselves by establishing the shoot or root meristems. In Arabidopsis (Arabidopsis thaliana) a two-step culture system ensures regeneration by first promoting the acquisition of pluripotency and subsequently specifying the fate of new meristems. Although previous studies have reported the importance of phytohormones auxin and cytokinin in determining the fate of new meristems, it remains elusive whether and how the environmental factors influence this process. In this study, we investigated the impact of light signals on shoot regeneration using Arabidopsis hypocotyl as explants. We found that light signals promote shoot regeneration while inhibiting root formation. ELONGATED HYPOCOTYL 5 (HY5), the pivotal transcriptional factor in light signaling, plays a central role in this process by mediating the expression of key genes controlling the fate of new meristems. Specifically, HY5 directly represses root development genes and activates shoot meristem genes, leading to the establishment of shoot progenitor from pluripotent callus. We further demonstrated that the early activation of photosynthesis is critical for shoot initiation, and this is transcriptionally regulated downstream of the HY5-dependent pathways. In conclusion, we uncovered the intricate molecular mechanisms by which light signals control the establishment of new meristem through the regulatory network governed by HY5, thus, highlighting the influence of light signals on plant developmental plasticity.
Project description:Transcriptional response of A. thaliana Root and Shoot tissue to light stress and presence of microbial communities in myc2-3 and MYC2-Flag lines
Project description:MYC2 is a central node controlling the crosstalk between JA and other phytohormone signalling pathways and regulating responses to light and circadian clock. We hypothesized that this transcription factor might coordinate prioritization of microbiota-induced growth over defense under suboptimal light conditions
Project description:We profiled the root and shoot transcriptomes of BFO-colonized (Bacteria, Fungi, Oomycetes) and germ free A. thaliana exposed to Low PAR (photoactive radiation, LP) and normal condition (NC) in the gnotobiotic FlowPot system five weeks post inoculation.
Project description:Arabidopsis plants (Col-0) were hydroponically grown for 10 days at 22°C under 30~40 μE·m−2·s−1 and continuous light conditions. Treatment with 100 mM H2O2 or sterile distilled water as mock control by spraying for shoot treatments, or dipping for root treatments. Relationship between treated and harvested tissue is as follows; shoot treatment-shoot sampling was analyzed at 1, 3, 6, 12, and 24h after the treatment, shoot treatment-root sampling, root treatment-shoot sampling, and root treatment-root sampling was analyzed at 6h after the treatment. Two biological replicates for each treatment were done by dye swaps (flip dyes). The data sets were normalized and filtered for quality control with GeneSpring12.5 (Agilent Technologies) using the default settings.
Project description:This experiment aimed to investigate which genes are involved in the early photomorphogenic root development of dark grown roots when only the shoot was exposed to light.
Project description:Light spectrum quality is an important signal for plant growth and development. We aimed to analyze the effects of different light spectra on in vitro shoot development and proteomic and polyamine (PA) profiles in shoots of Cedrela fissilis. Cotyledonary and apical nodal segments were grown under different light emitting diode (LED) lamps and a fluorescent lamp. Shoots from cotyledonary nodal segments cultured with 6-benzyladenine (BA) grown under WmBdR LED increased their length, fresh and dry matter compared to shoots grown under fluorescent light. A non-redundant protein databank generated by transcriptome sequencing and de novo assembly of C. fissilis improved, and almost doubled, protein identification compared to a Citrus sinensis databank. Using the C. fissilis protein databank, a total of 616 proteins were identified, with 23 up- and 103 downaccumulated in shoots under WmBdR LED compared to fluorescent lamp. Differential accumulation of argininosuccinate synthase protein was associated with an increase in free-Put contents and, consequently, with higher shoot elongation under WmBdR LED. Furthermore, the proteins S-adenosylmethionine synthase, which is related to PA and ethylene biosynthesis, and 1-aminocyclopropane-1-carboxylate oxidase, related to ethylene biosynthesis, were unique in shoots grown under fluorescent lamp, showing lower elongation of shoots, possibly due to ethylene production. The downaccumulation of calreticulin, heat shock proteins, plastid-lipid-associated protein, ubiquitin-conjugating enzymes, and ultraviolet-B receptor UVR8 isoform X1 could be related to better shoot length under LED. This work provides important data related to the effects of light spectrum quality on in vitro morphogenesis via modulation of specific proteins and free-Put biosynthesis.
