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International Journal of Molecular... Apr 2020Plant cell walls surround cells and provide both external protection and a means of cell-to-cell communication [...].
Plant cell walls surround cells and provide both external protection and a means of cell-to-cell communication [...].
Topics: Cell Membrane; Cell Wall; Plant Cells; Plant Development; Plant Proteins
PubMed: 32326416
DOI: 10.3390/ijms21082731 -
BMC Plant Biology Apr 2016Being sessile organisms, plants are often exposed to a wide array of abiotic and biotic stresses. Abiotic stress conditions include drought, heat, cold and salinity,... (Review)
Review
BACKGROUND
Being sessile organisms, plants are often exposed to a wide array of abiotic and biotic stresses. Abiotic stress conditions include drought, heat, cold and salinity, whereas biotic stress arises mainly from bacteria, fungi, viruses, nematodes and insects. To adapt to such adverse situations, plants have evolved well-developed mechanisms that help to perceive the stress signal and enable optimal growth response. Phytohormones play critical roles in helping the plants to adapt to adverse environmental conditions. The elaborate hormone signaling networks and their ability to crosstalk make them ideal candidates for mediating defense responses.
RESULTS
Recent research findings have helped to clarify the elaborate signaling networks and the sophisticated crosstalk occurring among the different hormone signaling pathways. In this review, we summarize the roles of the major plant hormones in regulating abiotic and biotic stress responses with special focus on the significance of crosstalk between different hormones in generating a sophisticated and efficient stress response. We divided the discussion into the roles of ABA, salicylic acid, jasmonates and ethylene separately at the start of the review. Subsequently, we have discussed the crosstalk among them, followed by crosstalk with growth promoting hormones (gibberellins, auxins and cytokinins). These have been illustrated with examples drawn from selected abiotic and biotic stress responses. The discussion on seed dormancy and germination serves to illustrate the fine balance that can be enforced by the two key hormones ABA and GA in regulating plant responses to environmental signals.
CONCLUSIONS
The intricate web of crosstalk among the often redundant multitudes of signaling intermediates is just beginning to be understood. Future research employing genome-scale systems biology approaches to solve problems of such magnitude will undoubtedly lead to a better understanding of plant development. Therefore, discovering additional crosstalk mechanisms among various hormones in coordinating growth under stress will be an important theme in the field of abiotic stress research. Such efforts will help to reveal important points of genetic control that can be useful to engineer stress tolerant crops.
Topics: Disease Resistance; Gene Expression Regulation, Plant; Models, Biological; Plant Development; Plant Diseases; Plant Growth Regulators; Plant Proteins; Plants; Signal Transduction; Stress, Physiological
PubMed: 27079791
DOI: 10.1186/s12870-016-0771-y -
Trends in Plant Science May 2018Distribution patterns and finely-tuned concentration gradients of plant hormones govern plant growth and development. Gibberellin (GA) is a plant hormone regulating key... (Review)
Review
Distribution patterns and finely-tuned concentration gradients of plant hormones govern plant growth and development. Gibberellin (GA) is a plant hormone regulating key processes in plants; many of them are of significant agricultural importance, such as seed germination, root and shoot elongation, flowering, and fruit patterning. Although studies have demonstrated that GA movement is essential for multiple developmental aspects, how GAs are transported throughout the plant and where exactly they accumulate remain largely unknown. Here, we summarize recent findings from studies of GA movement and localization, and discuss the importance of GA intermediates in long- and short-distance movement. We further review recently identified Arabidopsis GA transporters and highlight their complex specialization and robust functional redundancy in GA transport activity.
Topics: Biological Transport; Gene Expression Regulation, Developmental; Gene Expression Regulation, Plant; Gibberellins; Plant Development; Plants; Signal Transduction
PubMed: 29530380
DOI: 10.1016/j.tplants.2018.02.005 -
Genes Nov 2021Abscisic acid (ABA) regulates various aspects of plant physiology, including promoting seed dormancy and adaptive responses to abiotic and biotic stresses. In addition,... (Review)
Review
Abscisic acid (ABA) regulates various aspects of plant physiology, including promoting seed dormancy and adaptive responses to abiotic and biotic stresses. In addition, ABA plays an im-portant role in growth and development under non-stressed conditions. This review summarizes phenotypes of ABA biosynthesis and signaling mutants to clarify the roles of basal ABA in growth and development. The promotive and inhibitive actions of ABA in growth are characterized by stunted and enhanced growth of ABA-deficient and insensitive mutants, respectively. Growth regulation by ABA is both promotive and inhibitive, depending on the context, such as concentrations, tissues, and environmental conditions. Basal ABA regulates local growth including hyponastic growth, skotomorphogenesis and lateral root growth. At the cellular level, basal ABA is essential for proper chloroplast biogenesis, central metabolism, and expression of cell-cycle genes. Basal ABA also regulates epidermis development in the shoot, by inhibiting stomatal development, and deposition of hydrophobic polymers like a cuticular wax layer covering the leaf surface. In the root, basal ABA is involved in xylem differentiation and suberization of the endodermis. Hormone crosstalk plays key roles in growth and developmental processes regulated by ABA. Phenotypes of ABA-deficient and insensitive mutants indicate prominent functions of basal ABA in plant growth and development.
Topics: Abscisic Acid; Ethylenes; Membrane Lipids; Plant Development; Plant Stomata; Waxes; Xylem
PubMed: 34946886
DOI: 10.3390/genes12121936 -
Plant Physiology Sep 2020The plant kingdom produces hundreds of thousands of low molecular weight organic compounds. Based on the assumed functions of these compounds, the research community has... (Review)
Review
The plant kingdom produces hundreds of thousands of low molecular weight organic compounds. Based on the assumed functions of these compounds, the research community has classified them into three overarching groups: primary metabolites, which are directly required for plant growth; secondary (or specialized) metabolites, which mediate plant-environment interactions; and hormones, which regulate organismal processes and metabolism. For decades, this functional trichotomy of plant metabolism has shaped theory and experimentation in plant biology. However, exact biochemical boundaries between these different metabolite classes were never fully established. A new wave of genetic and chemical studies now further blurs these boundaries by demonstrating that secondary metabolites are multifunctional; they can function as potent regulators of plant growth and defense as well as primary metabolites sensu lato. Several adaptive scenarios may have favored this functional diversity for secondary metabolites, including signaling robustness and cost-effective storage and recycling. Secondary metabolite multifunctionality can provide new explanations for ontogenetic patterns of defense production and can refine our understanding of plant-herbivore interactions, in particular by accounting for the discovery that adapted herbivores misuse plant secondary metabolites for multiple purposes, some of which mirror their functions in plants. In conclusion, recent work unveils the limits of our current functional classification system for plant metabolites. Viewing secondary metabolites as integrated components of metabolic networks that are dynamically shaped by environmental selection pressures and transcend multiple trophic levels can improve our understanding of plant metabolism and plant-environment interactions.
Topics: Adaptation, Physiological; Plant Development; Plants; Secondary Metabolism
PubMed: 32636341
DOI: 10.1104/pp.20.00433 -
Cellular and Molecular Life Sciences :... May 2021Crop productivity is directly dependent on the growth and development of plants and their adaptation during different environmental stresses. Histone acetylation is an... (Review)
Review
Crop productivity is directly dependent on the growth and development of plants and their adaptation during different environmental stresses. Histone acetylation is an epigenetic modification that regulates numerous genes essential for various biological processes, including development and stress responses. Here, we have mainly discussed the impact of histone acetylation dynamics on vegetative growth, flower development, fruit ripening, biotic and abiotic stress responses. Besides, we have also emphasized the information gaps which are obligatory to be examined for understanding the complete role of histone acetylation dynamics in plants. A comprehensive knowledge about the histone acetylation dynamics will ultimately help to improve stress resistance and reduce yield losses in different crops due to climate changes.
Topics: Acetylation; Histones; Humans; Plant Development; Plants; Stress, Physiological
PubMed: 33638653
DOI: 10.1007/s00018-021-03794-x -
Annual Review of Plant Biology May 2023Regulatory elements encode the genomic blueprints that ensure the proper spatiotemporal patterning of gene expression necessary for appropriate development and responses... (Review)
Review
Regulatory elements encode the genomic blueprints that ensure the proper spatiotemporal patterning of gene expression necessary for appropriate development and responses to the environment. Accumulating evidence implicates changes to gene expression as a major source of phenotypic novelty in eukaryotes, including acute phenotypes such as disease and cancer in mammals. Moreover, genetic and epigenetic variation affecting regulatory sequences over longer evolutionary timescales has become a recurring theme in studies of morphological divergence and local adaptation. Here, we discuss the functions of and methods used to identify various classes of regulatory elements, as well as their role in plant development and response to the environment. We highlight opportunities to exploit regulatory variants underlying plant development and environmental responses for crop improvement efforts. Although a comprehensive understanding of regulatory mechanisms in plants has lagged behind that in animals, we showcase several breakthrough findings that have profoundly influenced plant biology and shaped the overall understanding of transcriptional regulation in eukaryotes.
Topics: Animals; Regulatory Sequences, Nucleic Acid; Gene Expression Regulation; Genomics; Genome; Plant Development; Plants; Evolution, Molecular; Mammals
PubMed: 36608347
DOI: 10.1146/annurev-arplant-070122-030236 -
Microbiological Research Apr 2019Endophytic bacteria are the plant beneficial bacteria that thrive inside plants and can improve plant growth under normal and challenging conditions. They can benefit... (Review)
Review
Endophytic bacteria are the plant beneficial bacteria that thrive inside plants and can improve plant growth under normal and challenging conditions. They can benefit host plants directly by improving plant nutrient uptake and by modulating growth and stress related phytohormones. Indirectly, endophytic bacteria can improve plant health by targeting pests and pathogens with antibiotics, hydrolytic enzymes, nutrient limitation, and by priming plant defenses. To confer these benefits, the bacteria have to colonize the plant endosphere after colonizing the rhizosphere. The colonization is achieved using a battery of traits involving motility, attachment, plant-polymer degradation, and evasion of plant defenses. The diversity of endophytic colonizers depends on several bacteria, plant and environment specific factors. Some endophytic bacteria can have a broad host range and can be used as bioinoculants in developing a safe and sustainable agriculture system. This review elaborates the factors affecting diversity of bacterial endophytes, their host specificity and mechanisms of plant growth promotion. The review also accentuates various methods used to study endophytic communities, wild plants as a source of novel endophytic bacteria, and innovative approaches that may improve plant-endophyte association. Moreover, bacterial genes expressed in planta and challenges to study them are also discussed.
Topics: Bacteria; Endophytes; Host Specificity; Plant Development; Plant Roots; Plants; Rhizosphere; Symbiosis
PubMed: 30825940
DOI: 10.1016/j.micres.2019.02.001 -
Biomolecules Sep 2022The hormonal system plays a decisive role in the control of plant growth and development [...].
The hormonal system plays a decisive role in the control of plant growth and development [...].
Topics: Plant Development; Plant Growth Regulators
PubMed: 36139144
DOI: 10.3390/biom12091305 -
Current Biology : CB Jun 2022Walking through a garden or a crop field, you may notice that plants damaged by pests (insects or pathogens) look smaller than the same kind of plants nearby that are...
Walking through a garden or a crop field, you may notice that plants damaged by pests (insects or pathogens) look smaller than the same kind of plants nearby that are not damaged. An obvious explanation would be that damaged plants may have lost substantial photosynthetic tissue due to insect and pathogen activities. As such, plants may have a reduced ability to capture light and perform photosynthesis, which fuels the growth of plants. While this is likely part of the reason why damaged plants look smaller, there is also another and perhaps more fascinating explanation that we would like to discuss here in this primer. It turns out that plants attacked by insects, pathogens and other biotic stressors may 'purposely' slow down their growth and that this response is often systemic, meaning that it occurs throughout the plant and beyond the tissue that is damaged by pests. Interestingly, some chemicals or plant genetic mutations that simulate insect or pathogen attacks without causing a loss of photosynthetic tissue can also slow plant growth, suggesting the physical loss of photosynthetic tissue per se is not always a prerequisite for slowing down plant growth. In contrast, there are conditions under which plants need to grow rapidly. For example, plants grow quickly when searching for light during germination or under a shaded canopy due to crowding from neighboring plants. Under these conditions, rapid plant growth is often accompanied by increased susceptibility to pests, presumably because growth is prioritized over defense. This inverse growth-defense relationship is commonly known as the 'growth-defense trade-off' and may be considered one of the most fundamental principles of 'plant economics' that allows plants to adjust growth and defense based on external conditions (Figure 1). As plants must both grow and defend in order to reproduce and survive in the natural world, growth-defense trade-offs have important ecological consequences. In agricultural settings, crops have often been bred to maximize growth-related traits, which could inadvertently result in the loss of useful genetic traits for biotic defenses. Thus, deciphering the molecular mechanisms underlying growth-defense trade-off phenomena could impact future crop breeding strategies aimed at designing superior crop plants with high yields as well as the ability to defend against biotic stressors. Here, we discuss some of the prevailing hypotheses about growth-defense trade-offs, our current understanding of the underlying mechanisms, and the ongoing efforts to optimize growth-defense trade-offs in crop plants.
Topics: Animals; Crops, Agricultural; Insecta; Plant Breeding; Plant Development
PubMed: 35728544
DOI: 10.1016/j.cub.2022.04.070