Biostimulants in Plant Science: A Global Perspective

Frontiers in Plant Science, Journal Year: 2017, Volume and Issue: 7

Published: Jan. 26, 2017

This review presents a comprehensive and systematic study of the field plant biostimulants considers fundamental innovative principles underlying this technology. The elucidation biological basis biostimulant function is prerequisite for development science-based industry sound regulations governing these compounds. task defining as class compounds, however, made more complex by diverse sources present in market, which include bacteria, fungi, seaweeds, higher plants, animals humate-containing raw materials, wide diversity industrial processes utilized their preparation. To distinguish from existing legislative product categories we propose following definition "a formulated origin that improves productivity consequence novel or emergent properties constituents, not sole presence known essential nutrients, growth regulators, protective compounds." provided here important it emphasizes principle can be positively modulated through application molecules, mixtures an explicit mode action has been defined. Given difficulty determining "mode action" biostimulant, recognizing need market to attain legitimacy, suggest focus research validation should upon proof efficacy safety determination broad mechanism action, without requirement specific action. While there clear commercial imperative rationalize discrete products, also compelling case of, experimentation with expectation may lead identification molecules phenomenon, pathways processes, would have discovered if category did exist, was considered legitimate.

Language: Английский

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Melatonin: an ancient molecule that makes oxygen metabolically tolerable

Journal of Pineal Research, Journal Year: 2015, Volume and Issue: 59(4), P. 403 - 419

Published: Aug. 14, 2015

Abstract Melatonin is remarkably functionally diverse with actions as a free radical scavenger and antioxidant, circadian rhythm regulator, anti‐inflammatory immunoregulating molecule, an oncostatic agent. We hypothesize that the initial primary function of melatonin in photosynthetic cyanobacteria, which appeared on Earth 3.5–3.2 billion years ago, was antioxidant. The evolution antioxidant by this organism necessary photosynthesis associated generation toxic‐free radicals. other secondary functions came about much later evolution. also surmise mitochondria chloroplasts may be sites synthesis all eukaryotic cells possess these organelles. This prediction made basis eukaryotes developed from purple nonsulfur bacteria (which produce melatonin) cyanobacteria when they were engulfed early eukaryotes. Thus, we speculate melatonin‐synthesizing retained organelles became chloroplasts, respectively. That are likely formation supported observation organelle contains high levels not impacted blood concentrations. has remarkable array means it thwarts oxidative damage. It, well its metabolites, differentially effective scavenging variety reactive oxygen nitrogen species. Moreover, metabolites modulate large number antioxidative pro‐oxidative enzymes, leading to reduction metabolizing/producing enzymes mediated Keap1‐Nrf2‐ ARE pathway. Beyond direct indirect effects, physiological metabolic advantages enhance ability limit stress.

Language: Английский

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Functions of melatonin in plants: a review

Journal of Pineal Research, Journal Year: 2015, Volume and Issue: 59(2), P. 133 - 150

Published: June 19, 2015

The number of studies on melatonin in plants has increased significantly recent years. This molecule, with a large set functions animals, also shown great potential plant physiology. review outlines the main physiology higher plants. Its role as antistress agent against abiotic stressors, such drought, salinity, low and high ambient temperatures, UV radiation toxic chemicals, is analyzed. latest data their plant-pathogen interactions are discussed. Both biotic stresses produce significant increase endogenous levels, indicating its possible effector these situations. existence circadian rhythms levels been demonstrated some species, data, although limited, suggest central this molecule day/night cycles Finally, another aspect that led to volume research involvement aspects development regulation. Although hormone still far from being fully established, processes growth, rhizogenesis, photosynthesis seems evident. multiple changes gene expression caused by point multiregulatory capable coordinating many development. last aspect, together an alleviating-stressor agent, suggests excellent prospect for crop improvement.

Language: Английский

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Melatonin: A New Plant Hormone and/or a Plant Master Regulator?

Trends in Plant Science, Journal Year: 2018, Volume and Issue: 24(1), P. 38 - 48

Published: Nov. 13, 2018

Language: Английский

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Chemical Priming of Plants Against Multiple Abiotic Stresses: Mission Possible?

Trends in Plant Science, Journal Year: 2015, Volume and Issue: 21(4), P. 329 - 340

Published: Dec. 18, 2015

Language: Английский

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Melatonin and its relationship to plant hormones

Annals of Botany, Journal Year: 2017, Volume and Issue: 121(2), P. 195 - 207

Published: Aug. 17, 2017

Plant melatonin appears to be a multi-regulatory molecule, similar those observed in animals, with many specific functions plant physiology. In recent years, the number of studies on plants has increased significantly. One most studied actions is its effect biotic and abiotic stress, such as that produced by drought, extreme temperatures, salinity, chemical pollution UV radiation, among others.

Language: Английский

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Melatonin mediates the regulation of ABA metabolism, free-radical scavenging, and stomatal behaviour in two Malus species under drought stress

Journal of Experimental Botany, Journal Year: 2014, Volume and Issue: 66(3), P. 669 - 680

Published: Dec. 5, 2014

Melatonin pre-treatment significantly increases the tolerance of both drought-tolerant Malus prunifolia and drought-sensitive M. hupehensis plants. Its beneficial effects include better water conservation in leaves, less electrolyte leakage, steady chlorophyll contents, greater photosynthetic performance under stress conditions. selectively down-regulates MdNCED3, an abscisic acid (ABA) synthesis gene, up-regulates its catabolic genes, MdCYP707A1 MdCYP707A2, thereby reducing ABA contents drought-stressed also directly scavenges H2O2 enhances activities antioxidant enzymes to detoxify indirectly. These two mechanisms work synergistically improve functions stomata, i.e. causing them re-open. Plants can effectively regulate their balance drought conditions by up-regulating expression melatonin genes MdTDC1, MdAANAT2, MdT5H4, MdASMT1. Therefore, inducing production is important mechanism which plants counteract influence this abiotic stressor.

Language: Английский

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Melatonin biosynthesis in plants: multiple pathways catalyze tryptophan to melatonin in the cytoplasm or chloroplasts

Journal of Pineal Research, Journal Year: 2016, Volume and Issue: 61(4), P. 426 - 437

Published: Sept. 7, 2016

Melatonin is an animal hormone as well a signaling molecule in plants. It was first identified plants 1995, and almost all enzymes responsible for melatonin biosynthesis had already been characterized these species. from tryptophan requires four-step reactions. However, six genes, that is, TDC, TPH, T5H, SNAT, ASMT, COMT, have implicated the synthesis of plants, suggesting presence multiple pathways. Two major pathways proposed based on enzyme kinetics: One tryptophan/tryptamine/serotonin/N-acetylserotonin/melatonin pathway, which may occur under normal growth conditions; other tryptophan/tryptamine/serotonin/5-methoxytryptamine/melatonin when produce large amounts serotonin, example, upon senescence. The biosynthetic capacity associated with conversion to serotonin much higher than melatonin, yields low level Many intermediates are produced various subcellular compartments, such cytoplasm, endoplasmic reticulum, chloroplasts, either facilitates or impedes subsequent enzymatic steps. Depending pathways, final sites vary at cytoplasm differentially affect mode action

Language: Английский

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Phytomelatonin receptor PMTR1‐mediated signaling regulates stomatal closure in Arabidopsis thaliana

Journal of Pineal Research, Journal Year: 2018, Volume and Issue: 65(2)

Published: April 27, 2018

Melatonin has been detected in plants 1995; however, the function and signaling pathway of this putative phytohormone are largely undetermined due to a lack knowledge about its receptor. Here, we discovered first phytomelatonin receptor (CAND2/PMTR1) Arabidopsis thaliana found that melatonin governs receptor-dependent stomatal closure. The application induced closure through heterotrimeric G protein α subunit-regulated H2 O2 Ca2+ signals. mutant lines lacking AtCand2 encodes candidate protein-coupled were insensitive melatonin-induced Accordingly, production influx completely abolished cand2. CAND2 is membrane interacts with GPA1 expression was tightly regulated by various organs guard cells. showed saturable specific 125 I-melatonin binding, apparent Kd (dissociation constant) 0.73 ± 0.10 nmol/L (r2 = .99), demonstrating (PMTR1). Our results suggest regulation dependent on CAND2/PMTR1-mediated transduction cascade.

Language: Английский

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Melatonin: A master regulator of plant development and stress responses

Journal of Integrative Plant Biology, Journal Year: 2020, Volume and Issue: 63(1), P. 126 - 145

Published: July 17, 2020

Melatonin is a pleiotropic molecule with multiple functions in plants. Since the discovery of melatonin plants, numerous studies have provided insight into biosynthesis, catabolism, and physiological biochemical this important molecule. Here, we describe biosynthesis from tryptophan, as well its various degradation pathways The identification putative receptor plants has led to hypothesis that hormone involved regulating plant growth, aerial organ development, root morphology, floral transition. universal antioxidant activity role preserving chlorophyll might explain anti-senescence capacity aging leaves. An impressive amount research focused on modulating postharvest fruit ripening by expression ethylene-related genes. Recent evidence also indicated plant's response biotic stress, cooperating other phytohormones well-known molecules such reactive oxygen species nitric oxide. Finally, great progress been made towards understanding how alleviates effects abiotic stresses, including salt, drought, extreme temperature, heavy metal stress. Given diverse roles, propose master regulator

Language: Английский

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