To study the nature of the system-level cell, it is necessary to go beyond the individual regulators and target genes to study the regulatory network between transcription factors (TF). However, it is difficult to immediately dissect TF-mediated gene genome-wide regulatory network (GRN) by experiment. Here, we propose a hierarchical graphical models to estimate activity of TF mRNA expression by building complexes with cofactor TF protein and downstream regulatory networks TF concluded simultaneously.
Then we apply our model to the development of interest and the process of circadian rhythms in Arabidopsis thaliana. The calculations show that a specific sequence family bHLH TF HFR1 recruiting chromatin regulator HAC1 for flower development master regulator TF AG and AG by further activating the expression of histone acetylation. Both independent data and experimental results supported this invention. We also found the flower tissue specific H3K27ac CHIP-Seq peaks in the AG gene and motif HFR1 body in the middle of this H3K27ac peak. In addition, we verified that HFR1 physically interact with HAC1 by yeast two-hybrid experiments.
HFR1 relationship-HAC1 triplet-AG may imply that the development of flowers and circadian rhythms are bridged by epigenetic regulation and enrich the classical ABC model in the development of flowers. In addition, our network TF activity may serve as a general method to explain the molecular mechanisms in more complex biological regulatory processes. In the male germline plant, transposable elements (TES) were reactivated in the accompanying vegetative nucleus, which results from their siRNA production and movement of the shuttle is to strengthen TE siRNAs silencing in sperm.
However, the mechanism by which siRNA movement arranged the remains unexplored. Here we show that ARID1, a transcription factor that is constitutively expressed in vegetative nucleus but dynamic accumulated in generative cells (progenitor sperm) to promote the second pollen mitosis, mediates movement heterochromatic silencing siRNA to strengthen in the male germline.
Hierarchical graphical model reveals HFR1 bridging circadian rhythm and flower development in Arabidopsis thaliana
direct inhibition of photosynthesis by Cd dominate inhibition caused by micronutrient deficiencies in Cd / Zn hiperakumulator Arabidopsis halleri
This work revealed by imaging in vivo measurements in Cd / Zn hiperakumulator Arabidopsis halleri, how much stress Cd affects macronutrients (Ca, K) and micronutrients (Fe, Zn) distribution in the leaves. We directly correlate these changes with the biophysics of the light reactions of photosynthesis.
Plants were grown for 2 months at 10 pM Zn (= control), and supplemented with 10, 15, 50 or 75 pM Cd. Direct imaging of transient OJIP revealed that the bundle sheath cells more sensitive to the toxicity of Cd from mesophyll cells away from the vein. progressive inhibition of photosystem (PS) II reaction center and the quantum yield reduction of electron transport between QA and QB and then to the PSI acceptor observed. This correlates with a decrease in the dynamics of QA re-oxidation and decrease the operational efficiency of PSII.
Analysis by X-ray fluorescence device benchtop micro showed that most of the Cd accumulates in the blood vessels, and bounded Fe and Zn distribution of blood vessels, especially in the 75 pM Cd, while K concentration increased throughout the leaves. calcium distribution seems unaffected by Cd, but Cd excess trichomes inhibited the formation and thus reduced concentration of total Ca in the leaves. The results show differential tissue sensitivity to Cd, as evidenced by the inhibition of photosynthesis heterogeneous.
Description: Plant plant-arabidopsis matter lysate was prepared by homogenization using a proprietary technique. The matter was frozen in liquid nitrogen immediately after excision and then stored at -70°C. The plant plant-arabidopsis matter total protein is provided in a buffer including HEPES (pH 7.9), MgCl2, KCl, EDTA, Sucrose, Glycerol, Sodium deoxycholate, NP-40, and a cocktail of protease inhibitors. For quality control purposes, the plant-arabidopsis matter on SDS-PAGE gel is shown to be consistent for each lot by visualization with coomassie blue staining. The plant-arabidopsis matter is then Western analyzed by either GAPDH or β-actin antibody, and the expression level is consistent with each lot.
Part of this may result in the selective disruption of homeostasis of leaf nutrients. Photosynthesis better performance away from the veins compared to the bundle sheath cells, however, showed that direct inhibition of photosynthesis by Cd dominate inhibition caused by micronutrient deficiencies.
