Histone H3 lysine4 trimethylation-regulated GRF11 expression is essential for the iron-deficiency response in Arabidopsis thaliana.

Iron (Fe) homeostasis in plants is controlled by both transcription factors (TFs) and chromatin remodeling through histone modification. To date, few studies have reported the existence of histone modification in maintaining the Fe-deficiency response. However, the reports that do exist shed light on various histone modifications, but knowledge of the activation mark in Fe-deficiency response is lacking.

A Pair of Arabidopsis Diacylglycerol Kinases Essential for Gametogenesis and Endoplasmic Reticulum Phospholipid Metabolism in Leaves and Flowers.

Phosphatidic acid (PA) is a key phospholipid in glycerolipid metabolism and signaling. Diacylglycerol kinase (DGK) produces PA by phosphorylating diacylglycerol, a crucial step in PA metabolism. Although DGK activity is known to be involved in plant development and stress response, how specific DGK isoforms function in development and phospholipid metabolism remains elusive.

Chemoenzymatic Synthesis and Biological Evaluation for Bioactive Molecules Derived from Bacterial Benzoyl Coenzyme A Ligase and Plant Type III Polyketide Synthase.

Plant type III polyketide synthases produce diverse bioactive molecules with a great medicinal significance to human diseases. Here, we demonstrated versatility of a stilbene synthase (STS) from , which can accept various non-physiological substrates to form unnatural polyketide products. Three enzymes (4-coumarate CoA ligase, malonyl-CoA synthetase and engineered benzoate CoA ligase) along with synthetic chemistry was practiced to synthesize starter and extender substrates for STS.

Phytochemicals as modulators of β-cells and immunity for the therapy of type 1 diabetes: Recent discoveries in pharmacological mechanisms and clinical potential.

Type 1 diabetes (T1D) is a lethal autoimmune disease afflicting as many as 10 million people worldwide. Considerable advances have been made in early diagnosis and understanding the cause of T1D development. However, new remedies are still in great demand as TID remains an incurable disease.

Cholesteryl α-D-glucoside 6-acyltransferase enhances the adhesion of Helicobacter pylori to gastric epithelium.

Helicobacter pylori, the most common etiologic agent of gastric diseases including gastric cancer, is auxotrophic for cholesterol and has to hijack it from gastric epithelia. Upon uptake, the bacteria convert cholesterol to cholesteryl 6'-O-acyl-α-D-glucopyranoside (CAG) to promote lipid raft clustering in the host cell membranes. However, how CAG appears in the host to exert the pathogenesis still remains ambiguous.

A HemK class glutamine-methyltransferase is involved in the termination of translation and essential for iron homeostasis in Arabidopsis.

Iron (Fe) transport and utilization are controlled by Fe-dependent transcriptional cascades. Many genes participate in these processes, transcriptionally controlled by Fe-status. Thorough knowledge of the translational check-points is lacking.

The dual benefit of a dominant mutation in Arabidopsis IRON DEFICIENCY TOLERANT1 for iron biofortification and heavy metal phytoremediation.

One of the goals of biofortification is to generate iron-enriched crops to combat growth and developmental defects especially iron (Fe) deficiency anaemia. Fe-fortification of food is challenging because soluble Fe is unstable and insoluble Fe is nonbioavailable. Genetic engineering is an alternative approach for Fe-biofortification, but so far strategies to increase Fe content have only encompassed a few genes with limited success.

Membrane lipid polyunsaturation mediated by FATTY ACID DESATURASE 2 (FAD2) is involved in endoplasmic reticulum stress tolerance in Arabidopsis thaliana.

Unsaturation of membrane glycerolipid classes at their hydrophobic fatty acid tails critically affects the physical nature of the lipid molecule. In Arabidopsis thaliana, 7 fatty acid desaturases (FADs) differently desaturate each glycerolipid class in plastids and the endoplasmic reticulum (ER). Here, we showed that polyunsaturation of ER glycerolipids is required for the ER stress response.

Blast Fungal Genomes Show Frequent Chromosomal Changes, Gene Gains and Losses, and Effector Gene Turnover.

Pyricularia is a fungal genus comprising several pathogenic species causing the blast disease in monocots. Pyricularia oryzae, the best-known species, infects rice, wheat, finger millet, and other crops. As past comparative and population genomics studies mainly focused on isolates of P.

β-Glucuronidases of opportunistic bacteria are the major contributors to xenobiotic-induced toxicity in the gut.

Gut bacterial β-D-glucuronidases (GUSs) catalyze the removal of glucuronic acid from liver-produced β-D-glucuronides. These reactions can have deleterious consequences when they reverse xenobiotic metabolism. The human gut contains hundreds of GUSs of variable sequences and structures.

Smad-Independent BMP Signaling in Somatic Cells Limits the Size of the Germline Stem Cell Pool.

In developing organisms, proper tuning of the number of stem cells within a niche is critical for the maintenance of adult tissues; however, the involved mechanisms remain largely unclear. Here, we demonstrate that Thickveins (Tkv), a type I bone morphogenetic protein (BMP) receptor, acts in the Drosophila developing ovarian soma through a Smad-independent pathway to shape the distribution of BMP signal within the niche, impacting germline stem cell (GSC) recruitment and maintenance. Somatic Tkv promotes Egfr signaling to silence transcription of Dally, which localizes BMP signals on the cell surface.

Sensing and Signaling of Phosphate Starvation: From Local to Long Distance.

Phosphorus (P) is an essential nutrient, but low concentrations of phosphate (Pi), the predominant form in which it is acquired, in the soil often limits plant growth and reproduction. To adapt to low Pi availability, plants have developed intricate regulatory mechanisms that integrate the environmental stimuli with internal cues in order to exploit the use of P. These mechanisms include sensing external and internal Pi concentrations along with co-ordination between local and long-distance signaling pathways.

Experimental Evolution of Yeast for High-Temperature Tolerance.

Thermotolerance is a polygenic trait that contributes to cell survival and growth under unusually high temperatures. Although some genes associated with high-temperature growth (Htg+) have been identified, how cells accumulate mutations to achieve prolonged thermotolerance is still mysterious. Here, we conducted experimental evolution of a Saccharomyces cerevisiae laboratory strain with stepwise temperature increases for it to grow at 42 °C.

Mining the Human Tissue Proteome for Protein Citrullination.

Citrullination is a posttranslational modification of arginine catalyzed by five peptidylarginine deiminases (PADs) in humans. The loss of a positive charge may cause structural or functional alterations, and while the modification has been linked to several diseases, including rheumatoid arthritis (RA) and cancer, its physiological or pathophysiological roles remain largely unclear. In part, this is owing to limitations in available methodology to robustly enrich, detect, and localize the modification.

Scopoletin 8-Hydroxylase-Mediated Fraxetin Production Is Crucial for Iron Mobilization.

Iron (Fe) is an essential mineral nutrient and an important factor for the composition of natural plant communities. Low Fe availability in aerated soils with neutral or alkaline pH has led to the evolution of elaborate mechanisms that extract Fe from the soil solution. In Arabidopsis (), Fe is acquired by an orchestrated strategy that comprises mobilization, chelation, and reduction of Fe prior to its uptake.

Membrane glycerolipid equilibrium under endoplasmic reticulum stress in Arabidopsis thaliana.

Endoplasmic reticulum (ER) is an indispensable organelle for secretory protein synthesis as well as metabolism of phospholipids and their derivatives in eukaryotic cells. Various external and internal factors may cause an accumulation of aberrant proteins in the ER, which causes ER stress and activates cellular ER stress responses to cope with the stress. In animal research, molecular mechanisms for protein quality control upon ER stress are well documented; however, how cells maintain lipid homeostasis under ER stress is an emerging issue.

Phosphite-Mediated Suppression of Anthocyanin Accumulation Regulated by Mitochondrial ATP Synthesis and Sugars in Arabidopsis.

Despite the essential role of phosphate (Pi) in plant growth and development, how plants sense and signal the change of Pi supply to adjust its uptake and utilization is not yet well understood. Pi itself has been proposed to be a signaling molecule that regulates Pi starvation responses (PSRs) because phosphite (Phi), a non-metabolized Pi analog, suppresses several PSRs. In this study, we identified a phosphite-insensitive1 (phi1) mutant which retained anthocyanin, a visible PSR, in Phi-containing but Pi-deficient medium.

S-Nitrosoglutathione works downstream of nitric oxide to mediate iron-deficiency signaling in Arabidopsis.

Iron (Fe) is essential for plant growth and development. Knowledge of Fe signaling, from the beginning of perception to activation of the uptake process, is critical for crop improvement. Here, by using chemical screening, we identified a small molecule 3-amino-N-(3-methylphenyl)thieno[2,3-b]pyridine-2-carboxamide named R7 ('R' denoting repressor of IRON-REGULATED TRANSPORTER 1), that modulates Fe homeostasis of Arabidopsis.

Mobilization of Iron by Plant-Borne Coumarins.

Iron is one of the most abundant elements in soils, but its low phytoavailability at high pH restricts plant communities on alkaline soils to taxa that have evolved efficient strategies to increase iron solubility. Recent evidence provides support for a previously underestimated role of root-secreted coumarins in mobilizing iron through reduction and chelation as part of an orchestrated strategy evolved to improve the acquisition of iron from recalcitrant pools. Understanding the mechanisms that tune the production of iron-mobilizing coumarins and their intricate interplay with other biosynthesis pathways could yield clues for deciphering the molecular basis of 'iron efficiency' - the ability of plants to thrive on soils with limited iron availability - and may open avenues for generating iron-fortified crops.

Hedgehog signaling establishes precursors for germline stem cell niches by regulating cell adhesion.

Stem cells require different types of supporting cells, or niches, to control stem cell maintenance and differentiation. However, little is known about how those niches are formed. We report that in the development of the ovary, the Hedgehog (Hh) gradient sets differential cell affinity for somatic gonadal precursors to specify stromal intermingled cells, which contributes to both germline stem cell maintenance and differentiation niches in the adult.

One way. Or another? Iron uptake in plants.

Iron (Fe) and phosphorus (P), the latter taken up by plants as phosphate (Pi), are two essential nutrients that determine species distribution and often limit crop yield as a result of their low availability in most soils. Pi-deficient plants improve the interception of Pi by increasing the density of root hairs, thereby expanding the volume of soil to be explored. The increase in root-hair frequency results mainly from attenuated primary root growth, a process that was shown to be dependent on the availability of external Fe.

Dual Role of a SAS10/C1D Family Protein in Ribosomal RNA Gene Expression and Processing Is Essential for Reproduction in Arabidopsis thaliana.

In eukaryotic cells, ribosomal RNAs (rRNAs) are transcribed, processed, and assembled with ribosomal proteins in the nucleolus. Regulatory mechanisms of rRNA gene (rDNA) transcription and processing remain elusive in plants, especially their connection to nucleolar organization. We performed an in silico screen for essential genes of unknown function in Arabidopsis thaliana and identified Thallo (THAL) encoding a SAS10/C1D family protein.

Root-secreted nicotianamine from Arabidopsis halleri facilitates zinc hypertolerance by regulating zinc bioavailability.

Hyperaccumulators tolerate and accumulate extraordinarily high concentrations of heavy metals. Content of the metal chelator nicotianamine (NA) in the root of zinc hyperaccumulator Arabidopsis halleri is elevated compared with nonhyperaccumulators, a trait that is considered to be one of the markers of a hyperaccumulator. Using metabolite-profiling analysis of root secretions, we found that excess zinc treatment induced secretion of NA in A.