Leaf growth in dicots and monocots : so different yet so alike

In plants, most organs grow post-embryonically through cell division and cell expansion. The coordination of these two growth processes is generally considered to be different between dicots and monocots. In dicot plants, such as the model plant Arabidopsis, leaf growth is most often described as being temporally regulated with cell division ceasing earlier at the tip and continuing longer at the base of the leaf. Conversely, in monocot leaves, the organization of the growth processes is rather viewed as spatially regulated with dividing cells at the base of the leaf, followed by expanding cells and finally mature cells at the tip. As our understanding of the leaf growth processes in the two major classes of flowering plants expands, it becomes increasingly clear that the regulation of the growth processes is to a great extent conserved between dicots and monocots. In this review, we highlight how the temporal and spatial organization of cell division and cell expansion takes place in both dicot and monocot leaves. We also show that there are similarities in the molecular wiring that coordinates these two processes during leaf development

Emerging connections between small RNAs and phytohormones

Small RNAs (sRNAs), mainly including miRNAs and siRNAs, are ubiquitous in eukaryotes. sRNAs mostly negatively regulate gene expression via (post-)transcriptional gene silencing through DNA methylation, mRNA cleavage, or translation inhibition. The mechanisms of sRNA biogenesis and function in diverse biological processes, as well as the interactions between sRNAs and environmental factors, like (a)biotic stress, have been deeply explored. Phytohormones are central in the plant’s response to stress, and multiple recent studies highlight an emerging role for sRNAs in the direct response to, or the regulation of, plant hormonal pathways. In this review, we discuss recent progress on the unraveling of crossregulation between sRNAs and nine plant hormones

The Discovery of New Export Products in Ecuador

This paper examines export diversification in Ecuador in the cases of fresh cut flowers, canned tuna, palm heart, broccoli and mangoes, using the theoretical framework on “pioneers” and “discoveries” developed by Hausmann and Rodrik(2003), as well as work by Sánchez and Butler (2006) on export costs and related uncertainties. It is found that the discoveries were mainly of traditional competitive advantage, with various degrees of technology adoption. The following policy implications are derived: i) innovative mechanisms to share the costs of new discoveries must be found and intellectual property rights strengthened; ii) cooperation among industry experts needs to improve; iii) deeper collective action to promote public-private partnerships should be undertaken; iv) relevant information and knowledge should be made available to all interested parties; and v) a national-level agenda should be undertaken to increase private investment in promising sectors while promoting the creation of public goods and minimizing rent-seeking behavior.Export diversification, Ecuador

SCFSAP controls organ size by targeting PPD proteins for degradation in Arabidopsis thaliana

Control of organ size by cell proliferation and growth is a fundamental process, but the mechanisms that determine the final size of organs are largely elusive in plants. We have previously revealed that the ubiquitin receptor DA1 regulates organ size by repressing cell proliferation in Arabidopsis. Here we report that a mutant allele of STERILE APETALA (SAP) suppresses the da1-1 mutant phenotype. We show that SAP is an F-box protein that forms part of a SKP1/Cullin/F-box E3 ubiquitin ligase complex and controls organ size by promoting the proliferation of meristemoid cells. Genetic analyses suggest that SAP may act in the same pathway with PEAPOD1 and PEAPOD2, which are negative regulators of meristemoid proliferation, to control organ size, but does so independently of DA1. Further results reveal that SAP physically associates with PEAPOD1 and PEAPOD2, and targets them for degradation. These findings define a molecular mechanism by which SAP and PEAPOD control organ size

Sharing economy : An opportunity for the poorest? An explanatory study

Sharing economy, an opportunity for the poorest ? An exploratory study | King Baudouin FoundationThis study explores the concept of sharing economy, the magnitude of the phenomenon, and the issues that arise from it. It addresses the issue of sharing economy as a subject of studies and reflections, potentially empowering people living in precarious situations. It will serve as a basis for dialogues with actors on the field in Belgium and Europe in order to identify tracks of work for the future.This book is also available in French and Dutch. See on the webiste of the King Baudouin Foundation

Molecular networks regulating cell division during Arabidopsis leaf growth

Leaves are the primary organs for photosynthesis and as such have a pivotal role for plant growth and development. Leaf development is a multi-factorial and dynamic process involving many genes that regulate size, shape, and differentiation. The processes that mainly drive leaf development are cell proliferation and cell expansion, and numerous genes have been identified that, when ectopically expressed or down-regulated, increase cell number and/or cell size during leaf growth. Many of the genes regulating cell proliferation are functionally interconnected and can be grouped in regulatory modules. Here, we review our current understanding of six important gene regulatory modules affecting cell proliferation during Arabidopsis leaf growth: DA1-EOD1, GRF-GIF, SWI/SNF, GA-DELLA, KLU, and PEAPOD. Furthermore, we discuss how post-mitotic cell expansion and these six modules regulating cell proliferation make up final leaf size

The fate of P2Y-related orphan receptors: GPR80/99 and GPR91 are receptors of dicarboxylic acids

Several orphan G protein-coupled receptors are structurally close to the family of P2Y nucleotide receptors: GPR80/99 and GPR91 are close to P2Y1/2/4/6/11 receptors, whereas GPR87, H963 and GPR34 are close to P2Y12/13/14. Over the years, several laboratories have attempted without success to identify the ligands of those receptors. In early 2004, two papers have been published: One claiming that GPR80/99 is an AMP receptor, called P2Y15, and the other one showing that GPR80/99 is a receptor for α-ketoglutarate, while GPR91 is a succinate receptor. The accompanying paper by Qi et al. entirely supports that GPR80/99 is an α-ketoglutarate receptor and not an AMP receptor. The closeness of dicarboxylic acid and P2Y nucleotide receptors might be linked to the negative charges of both types of ligands and the involvement of conserved Arg residues in their neutralization

Helical mutations in type I collagen that affect the processing of the amino-propeptide result in an Osteogenesis Imperfecta/Ehlers-Danlos Syndrome overlap syndrome

Background: Whereas mutations affecting the helical domain of type I procollagen classically cause Osteogenesis Imperfecta (OI), helical mutations near the amino (N)-proteinase cleavage site have been suggested to result in a mixed OI/Ehlers-Danlos syndrome (EDS)-phenotype. Methods: We performed biochemical and molecular analysis of type I (pro-) collagen in a cohort of seven patients referred with a clinical diagnosis of EDS and showing only subtle signs of OI. Transmission electron microscopy of the dermis was available for one patient. Results: All of these patients harboured a COL1A1 / COL1A2 mutation residing within the most N-terminal part of the type I collagen helix. These mutations affect the rate of type I collagen N-propeptide cleavage and disturb normal collagen fibrillogenesis. Importantly, patients with this type of mutation do not show a typical OI phenotype but mainly present as EDS patients displaying severe joint hyperlaxity, soft and hyperextensible skin, abnormal wound healing, easy bruising, and sometimes signs of arterial fragility. In addition, they show subtle signs of OI including blue sclerae, relatively short stature and osteopenia or fractures. Conclusion: Recognition of this distinct phenotype is important for accurate genetic counselling, clinical management and surveillance, particularly in relation to the potential risk for vascular rupture associated with these mutations. Because these patients present clinical overlap with other EDS subtypes, biochemical collagen analysis is necessary to establish the correct diagnosis

Estrategias motivacionales para mejorar el desempeño académico de estudiantes de primaria de la escuela Ángel Felicísimo Rojas 2021-2022

El presente trabajo de investigación se centra en el hecho de dar respuesta a la interrogante: ¿qué características deberá tener un programa de estrategias motivacionales para mejorar el desempeño académico de los estudiantes del nivel de educación primaria de la Escuela Ángel Felicísimo Rojas del sector Bastión Popular de Guayaquil en el año lectivo 2021? La investigación radica en el hecho de la naturaleza de la docencia; ya que por medio de ella se presenta una mayor relevancia hacia las actividades educativas y por ende a despertar el interés motivacional de poder aprender los diferentes contenidos educativos; trayendo como consecuencia un mejor rendimiento de los estudiantes; lo cual como ya se ha mencionado ayudara a disminuir la deserción y mejorar el desempeño académico. El enfoque del estudio es cualitativo y su tipo descriptivo proyectivo bajo un diseño no experimental. El objetivo general se centra en proponer un programa de estrategias motivacionales para mejorar el desempeño académico. La investigación concluye que los docentes, padres y estudiantes reconocen la importancia del conocimiento de la autoestima, aunque no puntualizan como un motivo de bajo rendimiento escolar. Así mismo encontramos un escaso uso de metodologías y técnicas participativas, activas encaminadas al desarrollo de la autoestima. Cabe mencionar que los padres de familia son los llamados en satisfacer las necesidades tanto físicas como psicológicas se nota un desfase por falta de una acertada comunicación y convivencia familiar. Así mismo debe de tenerse en cuenta que el comportamiento de los estudiantes refleja el tipo de autoestima que posee alta o baja. Finalmente, la motivación no es un factor que determine el éxito o fracaso de una persona, pero si es un elemento que puede condicionar como encarar una situación determinada tanto en el plano social, laboral, educativo, afectivo