Suchergebnisse

Electronic control of biological processes with bioelectronic devices holds promise for sophisticated regulation of physiology, for gaining fundamental understanding of biological systems, providing new therapeutic solutions, and digitally mediating adaptations of organisms to external factors. The organic electronic ion pump (OEIP) provides a unique means for electronically-controlled, flow-free delivery of ions, and biomolecules at cellular scale. Here, a miniaturized OEIP device based on glass capillary fibers (c-OEIP) is implanted in a biological organism. The capillary form factor at the sub-100 mu m scale of the device enables it to be implanted in soft tissue, while its hyperbranched polyelectrolyte channel and addressing protocol allows efficient delivery of a large aromatic molecule. In the first example of an implantable bioelectronic device in plants, the c-OEIP readily penetrates the leaf of an intact tobacco plant with no significant wound response (evaluated up to 24 h) and effectively delivers the hormone abscisic acid (ABA) into the leaf apoplast. OEIP-mediated delivery of ABA, the phytohormone that regulates plants tolerance to stress, induces closure of stomata, the microscopic pores in leafs epidermis that play a vital role in photosynthesis and transpiration. Efficient and localized ABA delivery reveals previously unreported kinetics of ABA-induced signal propagation. ; Funding Agencies|Knut and Alice Wallenberg FoundationKnut & Alice Wallenberg Foundation; Swedish Research Council (VR)Swedish Research Council; Swedish Foundation for Strategic Research (SSF)Swedish Foundation for Strategic Research; Onnesjo Foundation; VINNOVAVinnova; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009-00971]; European UnionEuropean Union (EU) [800926]; Marie Sklodowska Curie Individual Fellowship (MSCA-IFEF-ST, Trans-Plant) [702641]

[EN] Nitric oxide (NO) is an important signaling compound in prokaryotes and eukaryotes. In plants, NO regulates critical developmental transitions and stress responses. Here, we identify a mechanism for NO sensing that coordinates responses throughout development based on targeted degradation of plant-specific transcriptional regulators, the group VII ethylene response factors (ERFs). We show that the N-end rule pathway of targeted proteolysis targets these proteins for destruction in the presence of NO, and we establish them as critical regulators of diverse NO-regulated processes, including seed germination, stomatal closure, and hypocotyl elongation. Furthermore, we define the molecular mechanism for NO control of germination and crosstalk with abscisic acid (ABA) signaling through ERF-regulated expression of ABSCISIC ACID INSENSITIVE5 (ABI5). Our work demonstrates how NO sensing is integrated across multiple physiological processes by direct modulation of transcription factor stability and identifies group VII ERFs as central hubs for the perception of gaseous signals in plants. ; M.J.H., S.P.P., D.J.G., G.M.M., J.V.C., and C.S.C. were supported by UK Biotechnology and Biological Sciences Research Council (BBSRC) grants BB/G02488X/1, BB/G010595/1, BB/F006934/1, and BB/K000144/1 (including financial support from SAB Miller plc); J.E.G. was supported by BB/K000063/1; N.M.I. by a MARA PhD fellowship from the Malaysian government; S.B. by a University of Nottingham PhD fellowship; and M.M. by a University of Sheffield Faculty of Science Studentship. D.J.G. was supported by a Nottingham Advanced Research Fellowship for part of this work. J.L.-J., A.C., and J.L. were supported by grants CSD2007-00057 and BIO2011-27526 from the Spanish government. G.W.B. was supported by a Marie Curie IIF Fellowship. The work of A.B. was supported by the Austrian Science foundation FWF (grants P21215 and P25488). Rothamsted Research receives grant-aided support from the BBSRC. D.F.A.T. and J.B. were funded by BBSRC grant ...

AbstractPlant height is among the most important agronomic traits influencing crop yield. Wheat lines carrying Rht genes are important in plant breeding due to their both higher yield capacity and better tolerance to certain environmental stresses. However, the effects of dwarf-inducing genes on stress acclimation mechanisms are still poorly understood. Under the present conditions, cadmium stress induced different stress responses and defence mechanisms in the wild-type and dwarf mutant, and the mutant with the Rht-B1c allele exhibited higher tolerance. In the wild type after cadmium treatment, the abscisic acid synthesis increased in the leaves, which in turn might have induced the polyamine and proline metabolisms in the roots. However, in the mutant line, the slight increment in the leaf abscisic acid content accompanied by relatively high salicylic acid accumulation was not sufficient to induce such a great accumulation of proline and putrescine. Although changes in proline and polyamines, especially putrescine, showed similar patterns, the accumulation of these compounds was antagonistically related to the phytochelatin synthesis in the roots of the wild type after cadmium stress. In the dwarf genotype, a favourable metabolic shift from the synthesis of polyamine and proline to that of phytochelatin was responsible for the higher cadmium tolerance observed.

To determine whether root-supplied ABA alleviates saline stress, tomato (Solanum lycopersicum L. cv. Sugar Drop) was grafted onto two independent lines (NCED OE) overexpressing the SlNCED1 gene (9-cis-epoxycarotenoid dioxygenase) and wild type rootstocks. After 200 days of saline irrigation (EC = 3.5 dS m), plants with NCED OE rootstocks had 30% higher fruit yield, but decreased root biomass and lateral root development. Although NCED OE rootstocks upregulated ABA-signalling (AREB, ATHB12), ethylene-related (ACCs, ERFs), aquaporin (PIPs) and stress-related (TAS14, KIN, LEA) genes, downregulation of PYL ABA receptors and signalling components (WRKYs), ethylene synthesis (ACOs) and auxin-responsive factors occurred. Elevated SlNCED1 expression enhanced ABA levels in reproductive tissue while ABA catabolites accumulated in leaf and xylem sap suggesting homeostatic mechanisms. NCED OE also reduced xylem cytokinin transport to the shoot and stimulated foliar 2-isopentenyl adenine (iP) accumulation and phloem transport. Moreover, increased xylem GA levels in growing fruit trusses were associated with enhanced reproductive growth. Improved photosynthesis without changes in stomatal conductance was consistent with reduced stress sensitivity and hormone-mediated alteration of leaf growth and mesophyll structure. Combined with increases in leaf nutrients and flavonoids, systemic changes in hormone balance could explain enhanced vigour, reproductive growth and yield under saline stress. ; European Union's Seventh Framework Programme, Grant/Award Number: 289365; MINECO-FEDER, Grant/Award Number: RTI2018-099113-B-I00. Research was also supported by the Spanish MINECO-FEDER (project RTI201 8-099113-B-I00) and by the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement # 289365 (project ROOTOPOWER). AJT and ZK were partly supported by Biotechnology and Biological Sciences Research Council (grant BB/L01954X/1) and MLG was partly supported by Biotechnology and Biological Sciences Research Council (grant BB/H109502/1)

Alternative splicing occurs in most human genes and contributes to protein diversity by producing multiple mRNAs from each gene. In this book, the authors present new developments in alternative splicing research. Topics discussed include alternative splicing alterations in Alzheimer's disease; plant RNA-binding proteins implicate mRNA processing in abscisic acid (ABA) responses; comprehensive analyses of alternative exons in neuronally differentiated P19 cells; an epigenetic view on alternative splicing; identification of genuine alternative splicing variants for rare or long-sized transcript

Front Cover -- Sustainable Agricultural Practices -- Copyright Page -- Contents -- List of contributors -- 1 Multifactorial stress combination, plant microbiome recruitment, and reactive oxygen species/antioxidant feedbacks for pl... -- 1.1 Introduction -- 1.2 Plant responses to multifactorial stress combination -- 1.3 Plant stress and abscisic acid crosstalk -- 1.4 Abscisic acid signaling and reactive oxygen species connection to cope with plant stress -- 1.5 Plant microbiome: the invisible life that helps plants against stress -- 1.6 Endophyte recruitment (cry for help strategy) under stress: from transitory altered state to plant resilience -- 1.7 Reactive oxygen species/antioxidants feedback for microbiome modulation, symbiosis, plant stress mitigation, and more: ... -- 1.8 Conclusions -- Acknowledgments -- References -- 2 Impact of COVID-19 on global agriculture and food sector -- 2.1 Introduction -- 2.2 Background -- 2.3 Control measures -- 2.3.1 Travel restriction -- 2.3.2 Border closure -- 2.3.3 Social distancing -- 2.4 Immediate impacts -- 2.4.1 Food production -- 2.4.2 Food processing -- 2.4.3 Connectivity: transport and distribution -- 2.4.4 Labor availability -- 2.4.5 Impairment of farm systems -- 2.4.6 Market and retailer -- 2.4.7 Consumer -- 2.5 Conclusions and future perspectives -- Acknowledgment -- References -- 3 State of the soil health before maize intercropped with Eucalyptus grandis under agroforestry environment in Limpopo Prov... -- 3.1 Introduction -- 3.2 Materials and methods -- 3.2.1 Nitrogen determination -- 3.2.2 Determination of functional diversity -- 3.2.3 Determination of soil microbial enzymatic activity -- 3.2.4 Statistical analyses -- 3.3 Results and discussion -- 3.3.1 Carbon source utilization profiles -- 3.3.2 Soil microbial enzymatic activity, viz. microbial activity -- 3.4 Conclusions -- References.

Open Access. ; Understanding the responses of maize to abscisic acid (ABA) dependent drought tolerance is an important topic for the biotechnological application of functional mechanisms of stress adaptation. Key components that control and modulate stress adaptive pathways include SnRK2 (sucrose non-fermenting 1-related protein kinases 2) proteins. Recent studies indicate that SnRK2 are plant specific kinases that together with ABA ligand PYR/PYL/RCAR proteins and type 2C group A protein phosphatases constitute the central core of abscisic acid perception and signal transduction. Here, we study drought responses in maize by analyzing the mechanism of ZmSnRK2.8 in ABA signaling to establish relevant analogies with other plant species. ZmSnRK2.8 is a very closely related protein to Arabidopsis OST1 (open stomata 1) kinase with nuclear and cytosolic subcellular localization able to auto-phosphorylate S182 or T183 amino acids on its activation loop suggesting that phosphorylation at these sites may be a general mechanism for SnRK2 activation. In addition, ZmSnRK2.8 is activated by ABA and interacts with PP2C phosphatases in a constitutive, ABA independent manner. Together, our data suggest a conserved mechanism of plant responses to ABA and drought stress in maize and point to the potential use of this kinase in improving programs of drought tolerance in crops. ; VL was financed by the Spanish MCYT (Program Ramon y Cajal) and BV by European Union Marie-Curie Early Stage Training Fellowships MEST-CT-2005–020232–2 ADONIS and the FCT SFRH/BD/62070/2009 grant. This work was supported by grants BIO2009–13044 from MCYT (Spain) and CIRIT-2005SGR00276 from Comissionat per Universitats i Recerca de la Generalitat de Catalunya to MP. ; Peer reviewed

Trabajo presentado en el III Spanish Symposium on Physiology and Breeding of Cereals (III Simposio Español de Fisiología y Mejora de Cereales), celebrado online el 17 y 18 de noviembre de 2020. ; Drought tolerance is a complex phenomenon comprising many physiological, biochemical and morphological changes at both aerial and below ground levels. In this work, we explore the strategy of two oat cultivars to cope with drought, over an imposed water deficit time course of 20 days, based on root morphological, anatomical, physiological and molecular studies. We observed that the susceptible genotype increased dramatically the abscisic acid, at a relative soil water content as high as 60% resulting in a reduction of stomatal conductance. Despite this, leaf water potential decreased simultaneously due to a decrease in root hydraulic conductivity (conductivity per root length) in this genotype that showed early drought symptoms. By contrast, the resistant genotype, showed a mild and slow increase in abscisic acid that allowed maintaining transpiration longer. This was associated with an increase in root hydraulic conductivity together with root architectural changes such as an increase in total root length and in the length of the thinnest roots. In addition, root anatomical changes facilitated hydraulic transport and a reduction of metabolic cost. This strategy allowed the resistance genotype to maintain higher water potential reducing drought symptoms and promoting growth under water deficit conditions. ; This work was supported by the Spanish Ministry of Science and Innovation [PID2019-104518RB-I00], and regional government through the AGR-253 group.

Abstract
Plants respond to various environmental stimuli in sophisticated ways. Takahashi et al. (2018) revealed that CLAVATA3/EMBRYO SURROUNDING REIGON-related 25 (CLE25) peptide is produced in roots under drought stress and transported to shoots, where it induces abscisic acid biosynthesis, resulting in drought resistance in Arabidopsis. However, the drought-related function of the CLE26 peptide, which has the same amino acid sequence as CLE25 (except for one amino acid substitution), is still unknown. In this study, a phenotypic analysis of Arabidopsis plants under repetitive drought stress treatment indicates that CLE26 is associated with drought stress memory and promotes survival rate at the second dehydration event. Additionally, we find that a loss-of-function mutant of a cell-wall-modifying gene, XYLANASE1 (XYN1), exhibits improved resistance to drought, which is suppressed by the mutation of CLE26. XYN1 is down-regulated in response to drought in wild-type plants. A further analysis shows that the synthetic CLE26 peptide is well transported in both xyn1 and drought-pretreated wild-type plants but not in untreated wild-type plants. These results suggest a novel cell wall function in drought stress memory; short-term dehydration down-regulates XYN1 in xylem cells, leading to probable cell wall modification, which alters CLE26 peptide transport, resulting in drought resistance under subsequent long-term dehydration.

14 p.-8 fig.-1 tab. ; Plant tolerance to freezing temperatures is governed by endogenous components and environmental factors. Exposure to low non-freezing temperatures is a key factor in the induction of freezing tolerance in the process called cold acclimation. The role of nitric oxide (NO) in cold acclimation was explored in Arabidopsis using triple nia1nia2noa1-2 mutants that are impaired in the nitrate-dependent and nitrate-independent pathways of NO production, and are thus NO deficient. Here, we demonstrate that cold-induced NO accumulation is required to promote the full cold acclimation response through C-repeat Binding Factor (CBF)-dependent gene expression, as well as the CBF-independent expression of other cold-responsive genes such as Oxidation-Related Zinc Finger 2 (ZF/OZF2). NO deficiency also altered abscisic acid perception and signaling and the cold-induced production of anthocyanins, which are additional factors involved in cold acclimation. ; This work was supported by grants from MINECO of Spain Government and FEDER EU funds [BIO2014-56067-P, BIO2017-82945-P to JL and BIO2016-79187-R to JS]. ; Peer reviewed

Front Cover -- Bacterial Secondary Metabolites -- Copyright Page -- Contents -- List of contributors -- Series preface -- Preface -- 1 Synthesis and application of bacterial secondary metabolites in agroecosystems: a note from the editors -- 1.1 Introduction -- 1.2 Bacterial bioactive compounds -- 1.2.1 Phytohormones -- 1.2.2 Extracellular polymeric substance -- 1.2.3 Pigments -- 1.2.4 Siderophores -- 1.2.5 Exopolysaccharides -- 1.2.6 ACC deaminase -- 1.2.7 Volatile organic compounds -- 1.2.8 Antibiotics -- 1.2.9 Hydrogen cyanide production -- 1.2.10 Lytic enzyme production -- 1.3 PGPB as multipotent bioagents -- 1.4 Effect of PGPR on plant growth promotion -- 1.5 PGPR-mediated plant growth promotion of stressed crops -- 1.6 Conclusions -- References -- 2 Bacterial exopolysaccharides for heavy metals and toxic dye removal: biosynthesis, mechanism, and remediation strategies -- 2.1 Introduction -- 2.2 Biosynthesis -- 2.3 Mechanism -- 2.4 Factors affecting biosorption -- 2.4.1 Effect of pH -- 2.4.2 Effect of temperature -- 2.4.3 Biomass concentration and binding sites -- 2.4.4 Initial pollutant concentration/metal ion concentration -- 2.5 Remediation strategies -- 2.5.1 Homogenous consortia EPS from living or dead biomass -- 2.5.2 Heterogeneous consortia EPS -- 2.5.3 Immobilized EPS -- 2.5.4 Flocculation, coagulation, and emulsification -- 2.5.5 Nanobiotechnology-based bioremediation -- 2.6 Conclusion -- References -- 3 Overview of secondary metabolites in cyanobacteria: a potential source of plant growth-promoting and abiotic stress resis... -- 3.1 Introduction -- 3.2 Secondary metabolites in cyanobacteria -- 3.2.1 Hormones -- 3.2.1.1 Auxin -- 3.2.1.2 Gibberellin -- 3.2.1.3 Ethylene -- 3.2.1.4 Cytokinin -- 3.2.1.5 Abscisic acid -- 3.2.2 Vitamins -- 3.2.3 Polysaccharides -- 3.2.4 Free fatty acids -- 3.2.5 Peptides -- 3.2.6 Pigments.

This review provides a comprehensive overview of the basic and applied aspects of different plant growth regulators in the regulation of growth and development of cucumber plants. The study is completely based on the use of secondary sources of data; related journals, government institutes, and relevant reports. Foliar application of PGRs has been shown to change the physiological and developmental processes, including plant vegetative growth, sex expression, yield, and yield components in cucumber. There are basically two types of growth regulators; plant growth promoters such as auxin, gibberellins, cytokinins, maleic hydrazide, ethephon, etc. and plant growth inhibitors such as ethylene, abscisic acids, dormins, etc. The combined use of auxins and gibberellins result in increased secondary growth. Maleic hydrazide (MH) along with Ethephon at 100 ppm each increases the number of nodes and primary branches. Ethrel at 300-400 ppm retards the secondary development and increase femaleness, and at 200-300 ppm make fruit surface smooth. Silver nitrate (AgNO3) at 400 ppm enhances the maleness in cucumber. Application of Ethephon at 300 ppm reduces the harvesting time of the fruit. Salicylic acid (at 2 doses of 0.07 mm/l + 0.18 mm/l) increases chlorophyll content and its exogenous application increases the fruit yield. Maleic Hydrazide (MH) alone at 100 ppm increases the femaleness, inhibits apical growth at 50-100 ppm, and increases fruit size at 200 ppm. Therefore, various auxin [indole-3-acetic acid (IAA), NAA], auxin transport inhibitor (TIBA), cytokinins (KIN), gibberellin [gibberellic acid (GA3)], ABA, ethylene [(2-chloroethylphosphonic acid (ethrel; ethephon; CEPA)] and growth retardant (MH) have been applied to control the vegetative growth and to maximize yield of cucumber. Numerous obstacles have hindered the quality cucumber production in Nepal; like environmental stresses, biotic and abiotic constraints, pest and disease outbreaks, and many others. The use of exogenous plant growth regulators has been ...

Arbuscular mycorrhizal fungi (AMF) are crucial components of fertile soils, able to provide several ecosystem services for crop production. Current economic, social and legislative contexts should drive the so-called "second green revolution" by better exploiting these beneficial microorganisms. Many challenges still need to be overcome to better understand the mycorrhizal symbiosis, among which (i) the biotrophic nature of AMF, constraining their production, while (ii) phosphate acts as a limiting factor for the optimal mycorrhizal inoculum application and effectiveness. Organism fitness and adaptation to the changing environment can be driven by the modulation of mitochondrial respiratory chain, strongly connected to the phosphorus processing. Nevertheless, the role of the respiratory function in mycorrhiza remains largely unexplored. We hypothesized that the two mitochondrial respiratory chain components, alternative oxidase (AOX) and cytochrome oxidase (COX), are involved in specific mycorrhizal behavior. For this, a complex approach was developed. At the pre-symbiotic phase (axenic conditions), we studied phenotypic responses of Rhizoglomus irregulare spores with two AOX and COX inhibitors [respectively, salicylhydroxamic acid (SHAM) and potassium cyanide (KCN)] and two growth regulators (abscisic acid – ABA and gibberellic acid – Ga3). At the symbiotic phase, we analyzed phenotypic and transcriptomic (genes involved in respiration, transport, and fermentation) responses in Solanum tuberosum/Rhizoglomus irregulare biosystem (glasshouse conditions): we monitored the effects driven by ABA, and explored the modulations induced by SHAM and KCN under five phosphorus concentrations. KCN and SHAM inhibited in vitro spore germination while ABA and Ga3 induced differential spore germination and hyphal patterns. ABA promoted mycorrhizal colonization, strong arbuscule intensity and positive mycorrhizal growth dependency (MGD). In ABA treated plants, R. irregulare induced down-regulation of StAOX gene isoforms and ...

Intro -- Contents -- Preface -- Chapter 1 -- Aquatic Bioresources: Utilization of Diversified Species, Products and Services for Strengthening Alternative Agriculture in Rural India -- Abstract -- Introduction -- Aquatic Floral Bioresources -- Lotus (Nelumbo nucifera) -- Water lily (Nymphaea odorata) -- Makhana (Euryale ferox) -- Water chestnut (Trapa bispinosa) -- Ipomoea (Ipomoea aquatica) -- Aquatic Faunal Bioresources -- Duckweeds in the Bioremediation of Domestic Sewage -- Conclusion -- References -- Chapter 2 -- Impact of Tropospheric Ozone and Particulate Matter on Plant Health -- Abstract -- Introduction -- Tropospheric Ozone -- Gas-Phase Chemistry of Tropospheric Ozone -- Ozone as Phytotoxic Agent -- Characterization of Ozone Exposure -- Ozone Deposition Mechanism -- Effects of Ozone on Physiology and Biochemistry of Plants -- Concentrations and Trends of Ozone in the Troposphere -- Particulate Matter -- Characteristics of Particulate Matter (PM) -- Deposition of PM -- Coarse (PM10) and Fine fraction (PM2.5) Particles -- Mode of Deposition -- Dry Deposition -- Wet Deposition -- Occult Deposition -- Deposition of PM onto Vegetation and It's Effects -- Plant Responses to Stress Caused by PM -- Effects of Tropospheric Ozone and Particulate Matter on Food Security -- Conclusion -- References -- Chapter 3 -- Productivity of Major Crops Worldwide: Reviewing Food Safety and Security -- Abstract -- Introduction -- Effect on Crop Productivity -- Effect on C3 and C4 Crop Biology -- Effect on Water Use Efficiency -- Effect on Rice -- Effect on Wheat -- Effect on Maize -- Effect on Sorghum -- Effect on Legumes -- Conclusion -- References -- Chapter 4 -- Plant Growth Regulators, Plant Adaptability and Plant Productivity: A Review on Abscisic Acid (ABA) Signaling in Plants Under Emerging Environmental Stresses -- Abstract -- Introduction