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Biotechnology Advances Nov 2019A key component in the management of many diseases of crops is the use of plant disease resistance genes. However, the discovery and then sequence identification of... (Review)
Review
A key component in the management of many diseases of crops is the use of plant disease resistance genes. However, the discovery and then sequence identification of these plant genes is challenging, whereas the characterization of the molecules that they recognize, the effector/avirulence products in pathogens, is often considerably more straight forward. Effectors are small proteins secreted by pathogens that can play major roles in modulating a plant's defense against attack. Effectors can be used to guide breeding of resistance genes, to trigger defense responses, and are part of integrated disease management strategies for crop protection. This review covers the role of effector-driven biotechnology in controlling plant diseases caused by fungi or oomycetes. Given that multi-billion dollar agriculture crops are based in some cases on plants recognizing just a handful of such effector proteins, there is considerable scope to use more fully effector proteins as a biotechnology resource in agriculture.
Topics: Biotechnology; Crops, Agricultural; Disease Resistance; Fungi; Host-Pathogen Interactions; Humans; Plant Diseases; Plant Proteins
PubMed: 31022532
DOI: 10.1016/j.biotechadv.2019.04.009 -
Current Opinion in Plant Biology Aug 2012A key feature of innate immunity is the ability to recognize and respond to potential pathogens in a highly sensitive and specific manner. In plants, the activation of... (Review)
Review
A key feature of innate immunity is the ability to recognize and respond to potential pathogens in a highly sensitive and specific manner. In plants, the activation of pattern recognition receptors (PRRs) by pathogen-associated molecular patterns (PAMPs) elicits a defense programme known as PAMP-triggered immunity (PTI). Although only a handful of PAMP-PRR pairs have been defined, all known PRRs are modular transmembrane proteins containing ligand-binding ectodomains. It is becoming clear that PRRs do not act alone but rather function as part of multi-protein complexes at the plasma membrane. Recent studies describing the molecular interactions and protein modifications that occur between PRRs and their regulatory proteins have provided important mechanistic insight into how plants avoid infection and achieve immunity.
Topics: Cell Membrane; Disease Resistance; Host-Pathogen Interactions; Membrane Proteins; Plant Diseases; Plant Immunity; Plants; Receptors, Pattern Recognition; Signal Transduction
PubMed: 22705024
DOI: 10.1016/j.pbi.2012.05.006 -
Plant & Cell Physiology Dec 2020Gibberellin (GA) hormones regulate the development of plants and their responses to environmental signals. The final part of GA biosynthesis is catalyzed by... (Review)
Review
Gibberellin (GA) hormones regulate the development of plants and their responses to environmental signals. The final part of GA biosynthesis is catalyzed by multifunctional 2-oxoglutarate-dependent dioxygenases, which are encoded by multigene families. According to their enzymatic properties and physiological functions, GA-oxidases are classified as anabolic or catabolic enzymes. Together they allow complex regulation of the GA biosynthetic pathway, which adapts the specific hormonal needs of a plant during development and interaction with its environment. In this review, we combine recent advances in enzymatic characterization of the multifunctional GA-oxidases, in particular, from cucumber and Arabidopsis that have been most comprehensively investigated.
Topics: Dioxygenases; Gibberellins; Plant Growth Regulators; Plant Proteins; Plants
PubMed: 32343806
DOI: 10.1093/pcp/pcaa051 -
Microbiological Reviews Mar 1992The discovery in 1977 that Agrobacterium species can transfer a discrete segment of oncogenic DNA (T-DNA) to the genome of host plant cells has stimulated an intense... (Review)
Review
The discovery in 1977 that Agrobacterium species can transfer a discrete segment of oncogenic DNA (T-DNA) to the genome of host plant cells has stimulated an intense interest in the molecular biology underlying these plant-microbe associations. This attention in turn has resulted in a series of insights about the biology of these organisms that continue to accumulate at an ever-increasing rate. This excitement was due in part to the notion that this unprecedented interkingdom DNA transfer could be exploited to create transgenic plants containing foreign genes of scientific or commercial importance. In the course of these discoveries, Agrobacterium became one of the best available models for studying the molecular interactions between bacteria and higher organisms. One extensively studied aspect of this association concerns the exchange of chemical signals between Agrobacterium spp. and host plants. Agrobacterium spp. can recognize no fewer than five classes of low-molecular-weight compounds released from plants, and other classes probably await discovery. The most widely studied of these are phenolic compounds, which stimulate the transcription of the genes needed for infection. Other compounds include specific monosaccharides and acidic environments which potentiate vir gene induction, acidic polysaccharides which induce one or more chromosomal genes, and a family of compounds called opines which are released from tumorous plant cells to the bacteria as nutrient sources. Agrobacterium spp. in return release a variety of chemical compounds to plants. The best understood is the transferred DNA itself, which contains genes that in various ways upset the balance of phytohormones, ultimately causing neoplastic cell proliferation. In addition to transferring DNA, some Agrobacterium strains directly secrete phytohormones. Finally, at least some strains release a pectinase, which degrades a component of plant cell walls.
Topics: Cell Communication; Gene Expression Regulation; Plants; Rhizobium; Transcriptional Activation
PubMed: 1579105
DOI: 10.1128/mr.56.1.12-31.1992 -
Biochimica Et Biophysica Acta Sep 2016Plant oil biosynthesis involves a complex metabolic network with multiple subcellular compartments, parallel pathways, cycles, and pathways that have a dual function to... (Review)
Review
Plant oil biosynthesis involves a complex metabolic network with multiple subcellular compartments, parallel pathways, cycles, and pathways that have a dual function to produce essential membrane lipids and triacylglycerol. Modern molecular biology techniques provide tools to alter plant oil compositions through bioengineering, however with few exceptions the final composition of triacylglycerol cannot be predicted. One reason for limited success in oilseed bioengineering is the inadequate understanding of how to control the flux of fatty acids through various fatty acid modification, and triacylglycerol assembly pathways of the lipid metabolic network. This review focuses on the mechanisms of acyl flux through the lipid metabolic network, and highlights where uncertainty resides in our understanding of seed oil biosynthesis. This article is part of a Special Issue entitled: Plant Lipid Biology edited by Kent D. Chapman and Ivo Feussner.
Topics: Fatty Acids; Lipid Metabolism; Lipids; Metabolic Networks and Pathways; Plant Oils; Plants; Triglycerides
PubMed: 27003249
DOI: 10.1016/j.bbalip.2016.03.021 -
Plant Biology (Stuttgart, Germany) Jan 2006Plant defences against pathogens and herbivorous insects form a comprehensive network of interacting signal transduction pathways. The signalling molecules salicylic... (Review)
Review
Plant defences against pathogens and herbivorous insects form a comprehensive network of interacting signal transduction pathways. The signalling molecules salicylic acid (SA) and jasmonic acid (JA) play important roles in this network. SA is involved in signalling processes providing systemic acquired resistance (SAR), protecting the plant from further infection after an initial pathogen attack. SAR is long-lasting and provides broad spectrum resistance to biotrophic pathogens that feed on a living host cell. The regulatory protein NPR1 is a central positive regulator of SAR. SA-activated NPR1 localizes to the nucleus where it interacts with TGA transcription factors to induce the expression of a large set of pathogenesis-related proteins that contribute to the enhanced state of resistance. In a distinct signalling process, JA protects the plant from insect infestation and necrotrophic pathogens that kill the host cell before feeding. JA activates the regulatory protein COI1 that is part of the E3 ubiquitin ligase-containing complex SCFCOI1, which is thought to derepress JA-responsive genes involved in plant defence. Both synergistic and antagonistic interactions have been observed between SA- and JA-dependent defences. NPR1 has emerged as a critical modulator of cross-talk between the SA and JA signal and is thought to aid in fine tuning defence responses specific to the encountered attacker. Here we review SA- and JA-dependent signal transduction and summarize our current understanding of the molecular mechanisms of cross-talk between these defences.
Topics: Arabidopsis Proteins; Cyclopentanes; Host-Parasite Interactions; Oxylipins; Plant Physiological Phenomena; Plants; Salicylic Acid; Signal Transduction
PubMed: 16435264
DOI: 10.1055/s-2005-872705 -
Plant Science : An International... Jun 2014As non-motile organisms, plants develop means to spread their progenies. Hygroscopic movement is a very common mechanism employed in seed dispersal. This type of... (Review)
Review
As non-motile organisms, plants develop means to spread their progenies. Hygroscopic movement is a very common mechanism employed in seed dispersal. This type of movement is created when the tissue desiccates and the cell walls dry and shrink. A contraction force develops, the direction and strength of which depends on the architecture of the tissue. This force may be utilized for a simple release of seeds, their catapultion, and for pushing seeds along the soil to a germination locus. We review the formation of a bend, a twist and a coil within various dispersal apparatuses as a reaction to the dehydration of the tissue. We compare the microscopic structures of hygroscopic devices supporting slow or fast movement, adaptations to dry or wet climates, and single use versus repeated movement. We discuss the development of the disconnecting tissues in relation to the development of a hygroscopic mechanism. As plant cultivation is dependent on seed dispersal control, we demonstrate that during the domestication of sesame and wheat, seed dispersal is avoided not due to a defective hygroscopic tissue, but rather a missing dehiscence tissue. Seed dispersal is a crucial stage in the life cycle of plants. Thus, hygroscopic movement plays a central part in plant ecology and agriculture.
Topics: Adaptation, Physiological; Movement; Plants; Seed Dispersal; Wettability
PubMed: 24767122
DOI: 10.1016/j.plantsci.2014.03.014 -
Current Biology : CB Dec 2020Organ development requires coordination between gene expression patterns and cellular processes across developmental axes to generate consistent shapes. A new study...
Organ development requires coordination between gene expression patterns and cellular processes across developmental axes to generate consistent shapes. A new study shows that, in plants, this coordination may be in part mediated by precise spatial hormone synthesis, regulated by a conserved family of genes.
Topics: Gene Expression Regulation, Plant; Indoleacetic Acids; Plant Leaves; Plants
PubMed: 33352134
DOI: 10.1016/j.cub.2020.10.041 -
Biochimica Et Biophysica Acta Feb 2012In terrestrial environments, temperature and water conditions are highly variable, and extreme temperatures and water conditions affect the survival, growth and... (Review)
Review
In terrestrial environments, temperature and water conditions are highly variable, and extreme temperatures and water conditions affect the survival, growth and reproduction of plants. To protect cells and sustain growth under such conditions of abiotic stress, plants respond to unfavourable changes in their environments in developmental, physiological and biochemical ways. These responses require expression of stress-responsive genes, which are regulated by a network of transcription factors. The AP2/ERF family is a large family of plant-specific transcription factors that share a well-conserved DNA-binding domain. This transcription factor family includes DRE-binding proteins (DREBs), which activate the expression of abiotic stress-responsive genes via specific binding to the dehydration-responsive element/C-repeat (DRE/CRT) cis-acting element in their promoters. In this review, we discuss the functions of the AP2/ERF-type transcription factors in plant abiotic stress responses, with special emphasis on the regulations and functions of two major types of DREBs, DREB1/CBF and DREB2. In addition, we summarise the involvement of other AP2/ERF-type transcription factors in abiotic stress responses, which has recently become clear. This article is part of a Special Issue entitled: Plant gene regulation in response to abiotic stress.
Topics: Gene Expression Regulation, Plant; Multigene Family; Phylogeny; Plant Physiological Phenomena; Plant Proteins; Plants; Stress, Physiological; Transcription Factors
PubMed: 21867785
DOI: 10.1016/j.bbagrm.2011.08.004 -
FEMS Microbiology Reviews Jul 2007Diverse bacterial species possess the ability to produce the auxin phytohormone indole-3-acetic acid (IAA). Different biosynthesis pathways have been identified and... (Review)
Review
Diverse bacterial species possess the ability to produce the auxin phytohormone indole-3-acetic acid (IAA). Different biosynthesis pathways have been identified and redundancy for IAA biosynthesis is widespread among plant-associated bacteria. Interactions between IAA-producing bacteria and plants lead to diverse outcomes on the plant side, varying from pathogenesis to phyto-stimulation. Reviewing the role of bacterial IAA in different microorganism-plant interactions highlights the fact that bacteria use this phytohormone to interact with plants as part of their colonization strategy, including phyto-stimulation and circumvention of basal plant defense mechanisms. Moreover, several recent reports indicate that IAA can also be a signaling molecule in bacteria and therefore can have a direct effect on bacterial physiology. This review discusses past and recent data, and emerging views on IAA, a well-known phytohormone, as a microbial metabolic and signaling molecule.
Topics: Bacteria; Bacterial Proteins; Gene Expression Regulation, Bacterial; Indoleacetic Acids; Plant Development; Plant Diseases; Plant Growth Regulators; Plants; Signal Transduction
PubMed: 17509086
DOI: 10.1111/j.1574-6976.2007.00072.x