Opposing effects of - and -cinnamic acid during rice coleoptile elongation.

The phenylpropanoid cinnamic acid (CA) is a plant metabolite that can occur under a - or -form. In contrast to the proven bioactivity of the -form (-CA), the activity of -CA (-CA) is still a matter of debate. We tested both compounds using a submerged rice coleoptile assay and demonstrated that they have opposite effects on cell elongation.

Detection and Quantification of Protein Aggregates in Plants.

Protein quality control is an important aspect of stress recovery. It maintains protein homeostasis through a machinery of regulatory proteins such as chaperones and proteases. When the system recognizes accumulation of misfolded or aggregated proteins, the cell recruits a set of regulatory proteins to initiate protein quality control.

Activity-based probes trap early active intermediates during metacaspase activation.

Metacaspases are essential cysteine proteases present in plants, fungi, and protists that are regulated by calcium binding and proteolytic maturation through mechanisms not yet understood. Here, we developed and validated activity-based probes for the three main metacaspase types, and used them to study calcium-mediated activation of metacaspases from their precursors . By combining substrate-inspired tetrapeptide probes containing an acyloxymethylketone (AOMK) reactive group, with purified representatives of type-I, type-II, and type-III metacaspases, we were able to demonstrate that labeling of mature metacaspases is strictly dependent on calcium.

ABA represses TOR and root meristem activity through nuclear exit of the SnRK1 kinase.

The phytohormone abscisic acid (ABA) promotes plant tolerance to major stresses such as drought, partly by modulating growth through poorly understood mechanisms. Here, we show that ABA-triggered repression of cell proliferation in the root meristem relies on the swift subcellular relocalization of SNF1-RELATED KINASE 1 (SnRK1). Under favorable conditions, the SnRK1 catalytic subunit, SnRK1α1, is enriched in the nuclei of root cells, and this is accompanied by normal cell proliferation and meristem size.

Evolutionary Genomics Reveals Multiple Functions of Arylalkylamine -Acetyltransferase in Fish.

As an important hormone, melatonin participates in endocrine regulation of diverse functions in vertebrates. Its biosynthesis is catalyzed by four cascaded enzymes, among them, arylalkylamine -acetyltransferase (AANAT) is the most critical one. Although only single gene has been identified in most groups of vertebrates, researchers including us have determined that fish have the most diverse of genes (, and ), playing various potential roles such as seasonal migration, amphibious aerial vision, and cave or deep-sea adaptation.

Characterization of RBPome in Oxidative Stress Conditions.

Cellular redox signaling is triggered by accumulation of various reactive oxygen species (ROS) that integrate with other signaling cascades to enable plants to ultimately respond to (a)biotic stresses. The identification of key regulators underlying redox signaling networks is therefore of high priority. This chapter describes an improved mRNA interactome capture method that allows to systematically detect oxidative stress responsive regulators in the post-transcriptional gene regulation (PTGR) pathway.

Measurement of NAD(P)H and NADPH-Generating Enzymes.

Pyridine nucleotides (NAD(H) and NADP(H)) are key redox carriers in cells and may also have other functions related to stress. These two molecules are crucial in linking metabolism to electron transport chains in photosynthesis and respiration, but they are also critical for ensuring redox signaling and homeostasis during episodes of stress. This is especially the case for NADPH, which must be generated from its oxidized form, NADP, by key dehydrogenases.

Detection of Damage-Activated Metacaspase Activity by Western Blot in Plants.

Metacaspases are cysteine proteases that are present in plants, protists, fungi, and bacteria. Previously, we found that physical damage, e.g.

The genome of reveals its adaptation to saline and waterlogged habitat.

is a semi-mangrove species with strong tolerance to salt and waterlogging stress. However, the molecular basis and mechanisms that underlie this strong adaptability to harsh environments remain poorly understood. Here, we assembled a high-quality, chromosome-level genome of this semi-mangrove plant and analyzed its transcriptome under different stress treatments to reveal regulatory responses and mechanisms.

Chemical Perturbation of Chloroplast Ca Dynamics in Arabidopsis thaliana Suspension Cell Cultures and Seedlings.

Ca signaling is part of universal signal transduction pathways to respond to external and internal stimuli or stress and in plants plays a central role in chloroplasts, such as in the regulation of photosynthetic enzymes or the transition from light to dark. Only recently, the underlying molecular machinery, e.g.

The Cycas genome and the early evolution of seed plants.

Cycads represent one of the most ancient lineages of living seed plants. Identifying genomic features uniquely shared by cycads and other extant seed plants, but not non-seed-producing plants, may shed light on the origin of key innovations, as well as the early diversification of seed plants. Here, we report the 10.

Interaction between photoperiod and variation in circadian rhythms in tomato.

Background: Many biological processes follow circadian rhythmicity and are controlled by the circadian clock. Predictable environmental changes such as seasonal variation in photoperiod can modulate circadian rhythms, allowing organisms to adjust the timing of their biological processes to the time of the year. In some crops such as rice, barley or soybean, mutations in circadian clock genes have altered photoperiod sensitivity, enhancing their cultivability in specific seasons and latitudes.

MicroRNA-mediated post-transcriptional regulation of Pinus pinaster response and resistance to pinewood nematode.

Pine wilt disease (PWD), caused by the parasitic nematode Bursaphelenchus xylophilus, or pinewood nematode (PWN), is a serious threat to pine forests in Europe. Pinus pinaster is highly susceptible to the disease and it is currently the most affected European pine species. In this work, we investigated the role of small RNAs (sRNAs) in regulating P.

Evolution of Resistance Genes in Magnoliids: Dramatic Expansions of and Multiple Losses of .

Magnoliids are the third-largest group of angiosperms and occupy a critical position in angiosperm evolution. In the past years, due to the lack of sequenced genomes, the disease resistance gene ( gene) profile of magnoliids remains poorly understood. By the genome-wide identification of 1,832 genes from seven magnoliid genomes, we built a framework for the evolution of magnoliid genes.

Spatiotemporal development of suberized barriers in cork oak taproots.

The longevity and high activity of the cork cambium (or phellogen) from Quercus suber L. (cork oak) are the cornerstones for the sustainable exploitation of a unique raw material. Cork oak is a symbolic model to study cork development and cell wall suberization, yet most genetic and molecular studies on these topics have targeted other model plants.

An Oryza-specific hydroxycinnamoyl tyramine gene cluster contributes to enhanced disease resistance.

Genomic clustering of non-homologous genes for the biosynthesis of plant defensive compounds is an emerging theme, but insights into their formation and physiological function remain limited. Here we report the identification of a newly discovered hydroxycinnamoyl tyramine (HT) gene cluster in rice. This cluster contains a pyridoxamine 5'-phosphate oxidase (OsPDX3) producing the cofactor pyridoxal 5'-phosphate (PLP), a PLP-dependent tyrosine decarboxylase (OsTyDC1), and two duplicated hydroxycinnamoyl transferases (OsTHT1 and OsTHT2).

B1-type cyclins control microtubule organization during cell division in Arabidopsis.

Flowering plants contain a large number of cyclin families, each containing multiple members, most of which have not been characterized to date. Here, we analyzed the role of the B1 subclass of mitotic cyclins in cell cycle control during Arabidopsis development. While we reveal CYCB1;5 to be a pseudogene, the remaining four members were found to be expressed in dividing cells.

Plant signaling: Interplay of brassinosteroids and auxin in root meristems.

The plant hormones brassinosteroids (BRs) and auxin interact to regulate root meristem size. A new study reveals dual and opposing roles for BRs in auxin biosynthesis and signaling output in the Arabidopsis root epidermis, demonstrating that epidermis-derived BR signaling is required for root meristem maintenance through its effect on auxin signaling.

Gradual evolution of allopolyploidy in Arabidopsis suecica.

Most diploid organisms have polyploid ancestors. The evolutionary process of polyploidization is poorly understood but has frequently been conjectured to involve some form of 'genome shock', such as genome reorganization and subgenome expression dominance. Here we study polyploidization in Arabidopsis suecica, a post-glacial allopolyploid species formed via hybridization of Arabidopsis thaliana and Arabidopsis arenosa.

Periodic root branching is influenced by light through an HY1-HY5-auxin pathway.

The spacing of lateral roots (LRs) along the main root in plants is driven by an oscillatory signal, often referred to as the "root clock" that represents a pre-patterning mechanism that can be influenced by environmental signals. Light is an important environmental factor that has been previously reported to be capable of modulating the root clock, although the effect of light signaling on the LR pre-patterning has not yet been fully investigated. In this study, we reveal that light can activate the transcription of a photomorphogenic gene HY1 to maintain high frequency and amplitude of the oscillation signal, leading to the repetitive formation of pre-branch sites.