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Plant, Cell & Environment Apr 2021Plant population density is an important variable in agronomy and forestry and offers an experimental way to better understand plant-plant competition. We made a... (Review)
Review
Plant population density is an important variable in agronomy and forestry and offers an experimental way to better understand plant-plant competition. We made a meta-analysis of responses of even-aged mono-specific stands to population density by quantifying for 3 stand and 33 individual plant variables in 334 experiments how much both plant biomass and phenotypic traits change with a doubling in density. Increasing density increases standing crop per area, but decreases the mean size of its individuals, mostly through reduced tillering and branching. Among the phenotypic traits, stem diameter is negatively affected, but plant height remains remarkably similar, partly due to an increased stem length-to-mass ratio and partly by increased allocation to stems. The reduction in biomass is caused by a lower photosynthetic rate, mainly due to shading of part of the foliage. Total seed mass per plant is also strongly reduced, marginally by lower mass per seed, but mainly because of lower seed numbers. Plants generally have fewer shoot-born roots, but their overall rooting depth seems hardly affected. The phenotypic plasticity responses to high densities correlate strongly with those to low light, and less with those to low nutrients, suggesting that at high density, shading affects plants more than nutrient depletion.
Topics: Biomass; Plant Development; Plant Physiological Phenomena; Plants; Population Density
PubMed: 33280135
DOI: 10.1111/pce.13968 -
Plant Signaling & Behavior Dec 2021The global electric circuit and the marine layer in coastal regions result in the presence of atmospheric negative polarity ions within the canopy of plants. This leads...
The global electric circuit and the marine layer in coastal regions result in the presence of atmospheric negative polarity ions within the canopy of plants. This leads to the hypothesis:In the presence of negative polarity atmospheric ions plants activate a plant wide system to absorb and utilize these negative polarity ions.This plant wide system, termed Extracellular Transport System (ETS), is focused on nitrate movement. The object of this paper is to verify the existence of ETS by characterizing 1) how ETS absorbs ion from the atmosphere and 2) within the plant how ETS moves ions from source to destination. Over the past 2-years characteristics of ETS were examined in pecans, pistachios, lemons, wine grapes, cotton, corn, avocados and chili peppers in production agriculture fields in Arizona and California. Nitrate movement was separated into three physical locations: Location I, in the atmosphere outside the plant; Location II, in the interfacial volume between the atmosphere and the plant surface; Location III, in the plant itself. The paper is divided into three parts. Each part is concerned with a particular location of nitrate movement. The major tool of verification is presentation of simultaneous patterns of nitrate ion arrival rate on a simulated plant surface and subsequent movement of nitrate within the extracellular region of the plant. Use of this tool is illustrated in corn, lemons, chili peppers and avocados.A base functionality of ETS has been developed: ETS is a transient, plant wide system wherein 1) nitrate ions are putatively absorbed by a variety of epidermal structures including trichomes and transferred into the extracellular region, 2) hydrated pathways are produced in the extracellular region through which these nitrate ions pass 3) electrical potential gradients are created in the extracellular region which provide a force field to provoke movement of nitrate ions through these pathways. Anthropomorphic climate has three dimensions: light, temperature and moisture. Phytomorphic climate has five dimensions: light, temperature, moisture, earth tides and atmospheric ion presence. ETS is a natural adaptation of plants to the transient nature of atmospheric negative polarity ion presence. It provides a mechanism for plants to utilize this ubiquitous and renewable source of nitrate.
Topics: Atmosphere; Nitrates; Plants
PubMed: 34554051
DOI: 10.1080/15592324.2021.1890431 -
PeerJ 2022As forested natural habitats disappear in the world, traditional, shade-coffee plantations offer an opportunity to conserve biodiversity and ecosystem services....
BACKGROUND
As forested natural habitats disappear in the world, traditional, shade-coffee plantations offer an opportunity to conserve biodiversity and ecosystem services. Traditional coffee plantations maintain a diversity of tree species that provide shade for coffee bushes and, at the same time, are important repositories for plants and animals that inhabited the original cloud forest. However, there is still little information about shade-coffee plantation's fungal diversity despite their relevance for ecosystem functioning as decomposers, symbionts and pathogens. Specifically, it is unknown if and what mycorrhizae-forming fungi can be found on the branches and trunks of coffee bushes and trees, which hold a diversity of epiphytes. Here, we evaluate fungal communities on specific plant microsites on both coffee bushes and shade trees. We investigate the ecological roles played by this diversity, with a special focus on mycorrhizae-forming fungi that may enable the establishment and development of epiphytic plants.
METHODS
We collected 48 bark samples from coffee bushes and shade trees (coffee; tree), from four plant microsites (upper and lower trunks, branches and twigs), in two shade-coffee plantations in the Soconusco region in southern Mexico, at different altitudes. We obtained ITS amplicon sequences that served to estimate alpha and beta diversity, to assign taxonomy and to infer the potential ecological role played by the detected taxa.
RESULTS
The bark of shade trees and coffee bushes supported high fungal diversity (3,783 amplicon sequence variants). There were no strong associations between community species richness and collection site, plant type or microsite. However, we detected differences in beta diversity between collection sites. All trophic modes defined by FUNGuild database were represented in both plant types. However, when looking into guilds that involve mycorrhizae formation, the CLAM test suggests that coffee bushes are more likely to host taxa that may function as mycorrhizae.
DISCUSSION
We detected high fungal diversity in shade-coffee plantations in Soconusco, Chiapas, possibly remnants of the original cloud forest ecosystem. Several mycorrhiza forming fungi guilds occur on the bark of coffee bushes and shade trees in this agroecosystem, with the potential of supporting epiphyte establishment and development. Thus, traditional coffee cultivation could be part of an integrated strategy for restoration and conservation of epiphytic populations. This is particularly relevant for conservation of threatened species of Orchidaceae that are highly dependent on mycorrhizae formation.
Topics: Animals; Ecosystem; Mexico; Biodiversity; Forests; Trees; Plants; Mycorrhizae
PubMed: 35789660
DOI: 10.7717/peerj.13610 -
FEMS Microbiology Ecology Oct 2023The root-associated soil microbiome contributes immensely to support plant health and performance against abiotic and biotic stressors. Understanding the processes that...
Plant species identity and plant-induced changes in soil physicochemistry-but not plant phylogeny or functional traits - shape the assembly of the root-associated soil microbiome.
The root-associated soil microbiome contributes immensely to support plant health and performance against abiotic and biotic stressors. Understanding the processes that shape microbial assembly in root-associated soils is of interest in microbial ecology and plant health research. In this study, 37 plant species were grown in the same soil mixture for 10 months, whereupon the root-associated soil microbiome was assessed using amplicon sequencing. From this, the contribution of direct and indirect plant effects on microbial assembly was assessed. Plant species and plant-induced changes in soil physicochemistry were the most significant factors that accounted for bacterial and fungal community variation. Considering that all plants were grown in the same starting soil mixture, our results suggest that plants, in part, shape the assembly of their root-associated soil microbiome via their effects on soil physicochemistry. With the increase in phylogenetic ranking from plant species to class, we observed declines in the degree of community variation attributed to phylogenetic origin. That is, plant-microbe associations were unique to each plant species, but the phylogenetic associations between plant species were not important. We observed a large degree of residual variation (> 65%) not accounted for by any plant-related factors, which may be attributed to random community assembly.
Topics: Soil Microbiology; Phylogeny; Soil; Microbiota; Bacteria; Plants; Plant Roots; Rhizosphere
PubMed: 37816673
DOI: 10.1093/femsec/fiad126 -
Philosophical Transactions of the Royal... Mar 2023Evidence that climate change will impact the ecology and evolution of individual plant species is growing. However, little, as yet, is known about how climate change... (Review)
Review
Evidence that climate change will impact the ecology and evolution of individual plant species is growing. However, little, as yet, is known about how climate change will affect interactions between plants and their pathogens. Climate drivers could affect the physiology, and thus demography, and ultimately evolutionary processes affecting both plant hosts and their pathogens. Because the impacts of climate drivers may operate in different directions at different scales of infection, and, furthermore, may be nonlinear, abstracting across these processes may mis-specify outcomes. Here, we use mechanistic models of plant-pathogen interactions to illustrate how counterintuitive outcomes are possible, and we introduce how such framing may contribute to understanding climate effects on plant-pathogen systems. We discuss the evidence-base derived from wild and agricultural plant-pathogen systems that could inform such models, specifically in the direction of estimates of physiological, demographic and evolutionary responses to climate change. We conclude by providing an overview of knowledge gaps and directions for future research in this important area. This article is part of the theme issue 'Infectious disease ecology and evolution in a changing world'.
Topics: Climate Change; Plants
PubMed: 36744564
DOI: 10.1098/rstb.2022.0017 -
International Journal of Molecular... Oct 2021Plant development processes are regulated by epigenetic alterations that shape nuclear structure, gene expression, and phenotypic plasticity; these alterations can... (Review)
Review
Plant development processes are regulated by epigenetic alterations that shape nuclear structure, gene expression, and phenotypic plasticity; these alterations can provide the plant with protection from environmental stresses. During plant growth and development, these processes play a significant role in regulating gene expression to remodel chromatin structure. These epigenetic alterations are mainly regulated by transposable elements (TEs) whose abundance in plant genomes results in their interaction with genomes. Thus, TEs are the main source of epigenetic changes and form a substantial part of the plant genome. Furthermore, TEs can be activated under stress conditions, and activated elements cause mutagenic effects and substantial genetic variability. This introduces novel gene functions and structural variation in the insertion sites and primarily contributes to epigenetic modifications. Altogether, these modifications indirectly or directly provide the ability to withstand environmental stresses. In recent years, many studies have shown that TE methylation plays a major role in the evolution of the plant genome through epigenetic process that regulate gene imprinting, thereby upholding genome stability. The induced genetic rearrangements and insertions of mobile genetic elements in regions of active euchromatin contribute to genome alteration, leading to genomic stress. These TE-mediated epigenetic modifications lead to phenotypic diversity, genetic variation, and environmental stress tolerance. Thus, TE methylation is essential for plant evolution and stress adaptation, and TEs hold a relevant military position in the plant genome. High-throughput techniques have greatly advanced the understanding of TE-mediated gene expression and its associations with genome methylation and suggest that controlled mobilization of TEs could be used for crop breeding. However, development application in this area has been limited, and an integrated view of TE function and subsequent processes is lacking. In this review, we explore the enormous diversity and likely functions of the TE repertoire in adaptive evolution and discuss some recent examples of how TEs impact gene expression in plant development and stress adaptation.
Topics: DNA Methylation; DNA Transposable Elements; Epigenesis, Genetic; Plant Development; Plant Physiological Phenomena; Plants; Stress, Physiological
PubMed: 34768817
DOI: 10.3390/ijms222111387 -
Mitochondrion Jul 2020The mitochondrial F-ATP synthase is responsible for coupling the transmembrane proton gradient, generated through the inner membrane by the electron transport chain, to... (Review)
Review
The mitochondrial F-ATP synthase is responsible for coupling the transmembrane proton gradient, generated through the inner membrane by the electron transport chain, to the synthesis of ATP. This enzyme shares a basic architecture with the prokaryotic and chloroplast ones, since it is composed of a catalytic head (F), located in the mitochondrial matrix, a membrane-bound part (F), together with a central and a peripheral stalk. In this review we compare the structural and functional properties of F-ATP synthase in plant mitochondria with those of yeast and mammals. We also present the physiological impact of the alteration of F-ATP synthase in plants, with a special regard to its involvement in cytoplasmic male sterility. Furthermore, we show the involvement of this enzyme in plant stress responses. Finally, we discuss the role of F-ATP synthase in shaping the curvature of the mitochondrial inner membrane and in permeability transition pore formation.
Topics: Gene Expression Regulation, Enzymologic; Mitochondria; Models, Molecular; Plant Proteins; Plants; Protein Conformation; Proton-Translocating ATPases; Stress, Physiological
PubMed: 32534049
DOI: 10.1016/j.mito.2020.06.001 -
Plant Physiology Apr 2024Small-molecule phytohormones exert control over plant growth, development, and stress responses by coordinating the patterns of gene expression within and between cells.... (Review)
Review
Small-molecule phytohormones exert control over plant growth, development, and stress responses by coordinating the patterns of gene expression within and between cells. Increasing evidence indicates that currently recognized plant hormones are part of a larger group of regulatory metabolites that have acquired signaling properties during the evolution of land plants. This rich assortment of chemical signals reflects the tremendous diversity of plant secondary metabolism, which offers evolutionary solutions to the daunting challenges of sessility and other unique aspects of plant biology. A major gap in our current understanding of plant regulatory metabolites is the lack of insight into the direct targets of these compounds. Here, we illustrate the blurred distinction between classical phytohormones and other bioactive metabolites by highlighting the major scientific advances that transformed the view of jasmonate from an interesting floral scent to a potent transcriptional regulator. Lessons from jasmonate research generally apply to other phytohormones and thus may help provide a broad understanding of regulatory metabolite-protein interactions. In providing a framework that links small-molecule diversity to transcriptional plasticity, we hope to stimulate future research to explore the evolution, functions, and mechanisms of perception of a broad range of plant regulatory metabolites.
Topics: Cyclopentanes; Oxylipins; Plant Growth Regulators; Gene Expression Regulation, Plant; Signal Transduction; Plants
PubMed: 38290050
DOI: 10.1093/plphys/kiae045 -
Current Opinion in Plant Biology Dec 2021Plants react to a myriad of biotic and abiotic environmental signals through specific cellular mechanisms required for survival under stress. Although pathogen... (Review)
Review
Plants react to a myriad of biotic and abiotic environmental signals through specific cellular mechanisms required for survival under stress. Although pathogen perception has been widely studied and characterized, salt stress perception and signaling remain largely elusive. Recent observations, obtained in the model plant Arabidopsis thaliana, show that perception of specific features of pathogens also allows plants to mount salt stress resilience pathways, highlighting the possibility that salt sensing and pathogen perception mechanisms partially overlap. We discuss these overlapping strategies and examine the emerging role of A. thaliana cell wall and plasma membrane components in activating both salt- and pathogen-induced responses, as part of exquisite mechanisms underlying perception of damage and danger. This knowledge helps understanding the complexity of plant responses to pathogens and salinity, leading to new hypotheses that could explain why plants evolved similar strategies to respond to these, at first sight, very different types of stimuli.
Topics: Arabidopsis; Arabidopsis Proteins; Gene Expression Regulation, Plant; Perception; Plants; Salinity; Salt Stress; Stress, Physiological
PubMed: 34856479
DOI: 10.1016/j.pbi.2021.102120 -
Molecules (Basel, Switzerland) Aug 2022The transition element molybdenum (Mo) is an essential micronutrient for plants, animals, and microorganisms, where it forms part of the active center of Mo enzymes. To... (Review)
Review
The transition element molybdenum (Mo) is an essential micronutrient for plants, animals, and microorganisms, where it forms part of the active center of Mo enzymes. To gain biological activity in the cell, Mo has to be complexed by a pterin scaffold to form the molybdenum cofactor (Moco). Mo enzymes and Moco are found in all kingdoms of life, where they perform vital transformations in the metabolism of nitrogen, sulfur, and carbon compounds. In this review, I recall the history of Moco in a personal view, starting with the genetics of Moco in the 1960s and 1970s, followed by Moco biochemistry and the description of its chemical structure in the 1980s. When I review the elucidation of Moco biosynthesis in the 1990s and the early 2000s, I do it mainly for eukaryotes, as I worked with plants, human cells, and filamentous fungi. Finally, I briefly touch upon human Moco deficiency and whether there is life without Moco.
Topics: Animals; Coenzymes; Eukaryota; Humans; Metalloproteins; Molybdenum; Molybdenum Cofactors; Plants; Pterins
PubMed: 35956883
DOI: 10.3390/molecules27154934