-
International Journal of Molecular... Feb 2021Plants are constantly exposed to a wide range of potential pathogens and to protect themselves, have developed a variety of chemical and physical defense mechanisms.... (Review)
Review
Plants are constantly exposed to a wide range of potential pathogens and to protect themselves, have developed a variety of chemical and physical defense mechanisms. Callose is a β-(1,3)-D-glucan that is widely distributed in higher plants. In addition to its role in normal growth and development, callose plays an important role in plant defense. Callose is deposited between the plasma membrane and the cell wall at the site of pathogen attack, at the plasmodesmata, and on other plant tissues to slow pathogen invasion and spread. Since it was first reported more than a century ago, defense-related callose deposition has been extensively studied in a wide-spectrum of plant-pathogen systems. Over the past 20 years or so, a large number of studies have been published that address the dynamic nature of pathogen-induced callose deposition, the complex regulation of synthesis and transport of defense-related callose and associated callose synthases, and its important roles in plant defense responses. In this review, we summarize our current understanding of the regulation and function of defense-related callose deposition in plants and discuss both the progresses and future challenges in addressing this complex defense mechanism as a critical component of a plant immune system.
Topics: Gene Expression Regulation, Plant; Glucans; Glucosyltransferases; Host-Pathogen Interactions; Plant Physiological Phenomena; Plant Proteins
PubMed: 33673633
DOI: 10.3390/ijms22052393 -
Molecular Plant Jan 2021The endoplasmic reticulum, chloroplasts, and mitochondria are major plant organelles for protein synthesis, photosynthesis, metabolism, and energy production. Protein... (Review)
Review
The endoplasmic reticulum, chloroplasts, and mitochondria are major plant organelles for protein synthesis, photosynthesis, metabolism, and energy production. Protein homeostasis in these organelles, maintained by a balance between protein synthesis and degradation, is essential for cell functions during plant growth, development, and stress resistance. Nucleus-encoded chloroplast- and mitochondrion-targeted proteins and ER-resident proteins are imported from the cytosol and undergo modification and maturation within their respective organelles. Protein folding is an error-prone process that is influenced by both developmental signals and environmental cues; a number of mechanisms have evolved to ensure efficient import and proper folding and maturation of proteins in plant organelles. Misfolded or damaged proteins with nonnative conformations are subject to degradation via complementary or competing pathways: intraorganelle proteases, the organelle-associated ubiquitin-proteasome system, and the selective autophagy of partial or entire organelles. When proteins in nonnative conformations accumulate, the organelle-specific unfolded protein response operates to restore protein homeostasis by reducing protein folding demand, increasing protein folding capacity, and enhancing components involved in proteasome-associated protein degradation and autophagy. This review summarizes recent progress on the understanding of protein quality control in the ER, chloroplasts, and mitochondria in plants, with a focus on common mechanisms shared by these organelles during protein homeostasis.
Topics: Homeostasis; Organelles; Plant Proteins; Protein Folding; Proteolysis; Unfolded Protein Response
PubMed: 33137518
DOI: 10.1016/j.molp.2020.10.011 -
Peptides Jun 2021Plant AMPs are usually cysteine-rich, and can be classified in several classes, including lipid transfer proteins (LTPs). LTPs are small plant cationic peptides, and can... (Review)
Review
Plant AMPs are usually cysteine-rich, and can be classified in several classes, including lipid transfer proteins (LTPs). LTPs are small plant cationic peptides, and can be classified in two subclasses, LTP (9-10 kDa) and LTP (7 kDa). They have been identified and isolated from various plant species and can be involved in a number of processes, including responses against several phytopathogens. LTP presents 4 parallel α- helices and a 3-helix fragment. These structures form a tunnel with large and small entrances. LTP presents 3 parallel α- helices, which form a cavity with triangular structure. Both LTP subclasses present a hydrophobic cavity, which makes interaction with different lipids and general hydrophobic molecules possible. Several studies report a broad spectrum of activity of plant LTPs, including antibacterial, antifungal, antiviral, antitumoral, and insecticidal activity. Thus, these molecules can be employed in human and animal health as an alternative to the conventional treatment of disease, well as providing the source of novel drugs. However, employing peptides in human health can present challenges, such as the toxicity of peptides, the difference between the results found in in vitro assays and in pre-clinical or clinical tests and their low efficiency against Gram-negative bacteria. In this context, plant LTPs can be an interesting alternative means by which to bypass such challenges. This review addresses the versatility of plant LTPs, their broad spectrum of activities and their potential applications in human and animal health and in agricultural production, and examines challenges in their biotechnological application.
Topics: Animals; Anti-Infective Agents; Antigens, Plant; Antineoplastic Agents; Biotechnology; Carrier Proteins; Humans; Models, Molecular; Plant Proteins; Protein Conformation
PubMed: 33746031
DOI: 10.1016/j.peptides.2021.170531 -
Chembiochem : a European Journal of... Jan 2021Pathogenesis-related (PR) proteins constitute a broad class of plant proteins with analogues found throughout nature from bacteria to higher eukaryotes. PR proteins were... (Review)
Review
Pathogenesis-related (PR) proteins constitute a broad class of plant proteins with analogues found throughout nature from bacteria to higher eukaryotes. PR proteins were first noted in plants as part of the hypersensitive response, but have since been assigned an array of biological roles. The PR10/Bet v1-like proteins are a subset of PR proteins characterized by an ability to bind a wide range of lipophilic ligands, uniquely positioning them as contributors to specialized biosynthetic pathways. PR10/Bet v1-like proteins participate in the production of plant alkaloids and phenolics including flavonoids, both as general binding proteins and in special cases as catalysts. Owing initially to the perceived allergenic properties of PR10/Bet v1-like proteins, many were studied at the structural level to elucidate the basis for ligand binding. These studies provided a foundation for more recent efforts to understand higher-level structural order and how PR10/Bet v1-like proteins catalyse key reactions in plant pathways. Synthetic biology aimed at reconstituting plant-specialized metabolism in microorganisms uses knowledge of these proteins to fine-tune performance in new systems.
Topics: Allergens; Molecular Structure; Plant Proteins
PubMed: 32700448
DOI: 10.1002/cbic.202000354 -
BMC Plant Biology Oct 2023Mechanosensitive (MS) ion channels provide efficient molecular mechanism for transducing mechanical forces into intracellular ion fluxes in all kingdoms of life. The...
Mechanosensitive (MS) ion channels provide efficient molecular mechanism for transducing mechanical forces into intracellular ion fluxes in all kingdoms of life. The mechanosensitive channel of small conductance (MscS) was one of the best-studied MS channels and its homologs (MSL, MscS-like) were widely distributed in cell-walled organisms. However, the origin, evolution and expansion of MSL proteins in plants are still not clear. Here, we identified more than 2100 MSL proteins from 176 plants and conducted a broad-scale phylogenetic analysis. The phylogenetic tree showed that plant MSL proteins were divided into three groups (I, II and III) prior to the emergence of chlorophytae algae, consistent with their specific subcellular localization. MSL proteins were distributed unevenly into each of plant species, and four parallel expansion was identified in angiosperms. In Brassicaceae, most MSL duplicates were derived by whole-genome duplication (WGD)/segmental duplications. Finally, a hypothetical evolutionary model of MSL proteins in plants was proposed based on phylogeny. Our studies illustrate the evolutionary history of the MSL proteins and provide a guide for future functional diversity analyses of these proteins in plants.
Topics: Phylogeny; Plants; Ion Channels; Plant Proteins; Evolution, Molecular
PubMed: 37794319
DOI: 10.1186/s12870-023-04479-2 -
Critical Reviews in Food Science and... 2023The development of novel protein sources to compensate for the expected future shortage of traditional animal proteins due to their high carbon footprint is a major... (Review)
Review
The development of novel protein sources to compensate for the expected future shortage of traditional animal proteins due to their high carbon footprint is a major contemporary challenge in the agri-food industry currently. Therefore, both industry and consumers are placing a greater emphasis on plant proteins as a sustainable source of protein to meet the growing nutritional demand of ever increasing population. In addition to being key alternatives, many plant-based foods have biological properties that make them potentially functional or health-promoting foods, particularly physiologically active peptides and proteins accounting for most of these properties. This review discusses the importance of plant-based protein as a viable and sustainable alternative to animal proteins. The current advances in plant protein isolation and production and characterization of bioactive hydrolysates and peptides from plant proteins are described comprehensively. Furthermore, the recent research on bioactivities and bioavailability of plant protein-derived bioactive peptides is reviewed briefly. The limitations of using bioactive peptides, regulatory criteria, and the possible future applications of plant protein-derived bioactive peptides are highlighted. This review may help understand plant proteins and their bioactive peptides and provide valuable suggestions for future research and applications in the food industry.
Topics: Peptides; Plant Proteins
PubMed: 35521961
DOI: 10.1080/10408398.2022.2067120 -
Plant Physiology and Biochemistry : PPB May 2022Brassica juncea var. tumida Tsen et Lee (Tumorous stem mustard) is an unique vegetable in China. Its enlarged tumorous stem was used as main raw material to produce...
Brassica juncea var. tumida Tsen et Lee (Tumorous stem mustard) is an unique vegetable in China. Its enlarged tumorous stem was used as main raw material to produce pickle (Zhacai). In practice, early-bolting happens around 15% of planting area all year and inhibits its production. Here, about 209 PP2C proteins were identified through HMMER software and divided into 13 sub-families in B. juncea. BjuPP2C52 belongs to E sub-family, was up-regulated at reproductive growth stages and interacts with BjuFKF1, a key protein in regulating plant photoperiod flowering, in vitro and in vivo. To explore interactive proteins, BjuPP2C52 was used as bait, 12 potential interactive proteins were screened from yeast library, and they are BjuCOL3, BjuCOL5, BjuAP2, BjuAP2-1, BjuSVP-1, BjuFLC-2, BjuSKP1f, BjuA014572, BjuA008686, BjuO002119, BjuB036787 and BjuA019268. Further study verified that 10 out of the 12 screened proteins interacted with BjuPP2C52 in vivo. qRT-PCR was conducted to understand the expression pattern of those 10 interactive proteins in different tissues and development stages in B. juncea. The results showed that BjuCOL3, BjuCOL5, BjuB036787 and BjuA019268 were significantly up-regulated, while BjuA008686 and BjuO002119 were down-regulated in flowers compared with other four tissues. In developmental stages, BjuCOL5, BjuAP2, BjuAP2-1, BjuA014572, BjuB036787 and BjuA019268 were significantly up-regulated, while BjuSVP-1, BjuA008686 and BjuO002119 were down-regulated at reproductive stages. Based on the results, BjuCOL5, BjuAP2, BjuAP2-1, BjuSVP-1, BjuA014572, BjuB036787 and BjuA019268 may function in regulating flowering time in B. juncea.
Topics: Flowers; Gene Expression Regulation, Plant; Humans; Mustard Plant; Phylogeny; Plant Proteins
PubMed: 35306327
DOI: 10.1016/j.plaphy.2022.03.013 -
Biochemical Society Transactions Apr 2021Asparaginyl endopeptidases (AEPs) are versatile enzymes that in biological systems are involved in producing three different catalytic outcomes for proteins, namely (i)... (Review)
Review
Asparaginyl endopeptidases (AEPs) are versatile enzymes that in biological systems are involved in producing three different catalytic outcomes for proteins, namely (i) routine cleavage by bond hydrolysis, (ii) peptide maturation, including macrocyclisation by a cleavage-coupled intramolecular transpeptidation and (iii) circular permutation involving separate cleavage and transpeptidation reactions resulting in a major reshuffling of protein sequence. AEPs differ in their preference for cleavage or transpeptidation reactions, catalytic efficiency, and preference for asparagine or aspartate target residues. We look at structural analyses of various AEPs that have laid the groundwork for identifying important determinants of AEP function in recent years, with much of the research impetus arising from the potential biotechnological and pharmaceutical applications.
Topics: Catalytic Domain; Cysteine Endopeptidases; Hydrolysis; Molecular Dynamics Simulation; Peptides; Plant Proteins; Protein Binding; Protein Conformation; Seed Storage Proteins; Substrate Specificity
PubMed: 33666219
DOI: 10.1042/BST20200908 -
Trends in Plant Science May 2022Self-incompatibility (SI) is a mechanism that many plant families employ to prevent self-fertilization. In the Brassicaceae, the S-haplotype-specific interaction of the... (Review)
Review
Self-incompatibility (SI) is a mechanism that many plant families employ to prevent self-fertilization. In the Brassicaceae, the S-haplotype-specific interaction of the pollen-borne ligand, and a stigma-specific receptor protein kinase triggers a signaling cascade that culminates in the rejection of self-pollen. While the upstream molecular components at the receptor level of the signaling pathway have been extensively studied, the intracellular responses beyond receptor activation were not as well understood. Recent research has uncovered several key molecules and signaling events that operate in concert for the manifestation of the self-incompatible responses in Brassicaceae stigmas. Here, we review the recent discoveries in both the compatible and self-incompatible pathways and provide new perspectives on the early stages of Brassicaceae pollen-pistil interactions.
Topics: Brassicaceae; Plant Proteins; Pollen; Pollination; Protein Kinases; Signal Transduction
PubMed: 34848142
DOI: 10.1016/j.tplants.2021.10.011 -
Molecular Plant Pathology Jun 2023The pathogenesis-related (PR) proteins of plants have originally been identified as proteins that are strongly induced upon biotic and abiotic stress. These proteins... (Review)
Review
The pathogenesis-related (PR) proteins of plants have originally been identified as proteins that are strongly induced upon biotic and abiotic stress. These proteins fall into 17 distinct classes (PR1-PR17). The mode of action of most of these PR proteins has been well characterized, except for PR1, which belongs to a widespread superfamily of proteins that share a common CAP domain. Proteins of this family are not only expressed in plants but also in humans and in many different pathogens, including phytopathogenic nematodes and fungi. These proteins are associated with a diverse range of physiological functions. However, their precise mode of action has remained elusive. The importance of these proteins in immune defence is illustrated by the fact that PR1 overexpression in plants results in increased resistance against pathogens. However, PR1-like CAP proteins are also produced by pathogens and deletion of these genes results in reduced virulence, suggesting that CAP proteins can exert both defensive and offensive functions. Recent progress has revealed that plant PR1 is proteolytically cleaved to release a C-terminal CAPE1 peptide, which is sufficient to activate an immune response. The release of this signalling peptide is blocked by pathogenic effectors to evade immune defence. Moreover, plant PR1 forms complexes with other PR family members, including PR5, also known as thaumatin, and PR14, a lipid transfer protein, to enhance the host's immune response. Here, we discuss possible functions of PR1 proteins and their interactors, particularly in light of the fact that these proteins can bind lipids, which have important immune signalling functions.
Topics: Humans; Proteins; Plants; Plant Diseases; Plant Proteins
PubMed: 36932700
DOI: 10.1111/mpp.13320