Amylolytic Activities in Cereal Seeds under Aerobic and Anaerobic Conditions

An adequate carbohydrate supply contributes to the survival of seeds under conditions of limited oxygen availability. The amount of soluble, readily fermentable carbohydrates in dry cereal seeds is usually very limited, with starch representing the main storage compound. Starch breakdown during the germination of cereal seeds is the result of the action of hydrolytic enzymes and only through the concerted action of [alpha]-amylase (EC 3.2.1.1), [beta]-amylase (EC 3.2.1.2), debranching enzyme (EC 3.2.1.41), and [alpha]-glucosidase (EC 3.2.1.20) can starch be hydrolyzed completely. We present here data concerning the complete set of starch-degrading enzymes in three cereals, rice (Oryza sativa L.), which is tolerant to anaerobiosis, and wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.), which are unable to germinate under anoxia. Among the cereal seeds tested under anoxia, only rice is able to degrade nonboiled, soluble starch, reflecting the ability to degrade the starch granules in vivo. This is explained by the presence of the complete set of enzymes needed to degrade starch completely either as the result of de novo synthesis ([alpha]-amylase, [beta]-amylase) or activation of preexisting, inactive forms of the enzyme (debranching enzyme, [alpha]-glucosidase). These enzymes are either absent or inactive in wheat and barley seeds kept under anaerobic conditions.     

Attachment Behavior of Shewanella putrefaciens onto Magnetite under Aerobic and Anaerobic Conditions

In this study, batch experiments were used to characterize attachment behavior of Shewanella putrefaciens strain 200R to ferrihydrite and magnetite. Attachment was quantified in batch experiments with a 0.01 M NaNO ₃ solution as a function of pH (ranging from 3 to 10), sorbed anion (PO₄ ^{3 ?} ), and growth conditions (aerobic vs. anaerobic). Electrophoretic mobility data was collected for S. putrefaciens cells and magnetite grains and used as a means to interpret the role of electrostatic interaction in attachment studies. Little difference in attachment behavior was observed as a function of growth conditions or surface treatments. The exception was at pH ranging from 2 to 4, under anaerobic conditions, where increased attachment was measured on magnetite surfaces with sorbed PO₄ ^{3 ?} . This increased attachment was attributed to development of Fe-PO₄ surface complexes or secondary mineral phases, resulting in altered surface interactions between cell and mineral surfaces. Attachment was irreversible and increased with time under anaerobic conditions even under elevated pH conditions unfavourable to electrostatic interactions between cells and mineral surfaces. These results suggest that electrophoretic mobility data in this system is not a good predictor of attachment behavior, while surface charge development via protonation and deprotonation of surface functional groups is consistent with experimental attachment data. In this study, S. putrefaciens appears to utilize polymers or pili to remain attached to Fe-oxides and this process may facilitate Fe reduction on these surfaces. Results from this study underscore the need for quantitative bulk measurements of microbial attachment to accurately predict partitioning of dissimilatory iron reducing bacteria between solution and solid phases.     

Metagenomic Analysis of Respiratory Tract DNA Viral Communities in Cystic Fibrosis and Non-Cystic Fibrosis Individuals

The human respiratory tract is constantly exposed to a wide variety of viruses, microbes and inorganic particulates from environmental air, water and food. Physical characteristics of inhaled particles and airway mucosal immunity determine which viruses and microbes will persist in the airways. Here we present the first metagenomic study of DNA viral communities in the airways of diseased and non-diseased individuals. We obtained sequences from sputum DNA viral communities in 5 individuals with cystic fibrosis (CF) and 5 individuals without the disease. Overall, diversity of viruses in the airways was low, with an average richness of 175 distinct viral genotypes. The majority of viral diversity was uncharacterized. CF phage communities were highly similar to each other, whereas Non-CF individuals had more distinct phage communities, which may reflect organisms in inhaled air. CF eukaryotic viral communities were dominated by a few viruses, including human herpesviruses and retroviruses. Functional metagenomics showed that all Non-CF viromes were similar, and that CF viromes were enriched in aromatic amino acid metabolism. The CF metagenomes occupied two different metabolic states, probably reflecting different disease states. There was one outlying CF virome which was characterized by an over-representation of Guanosine-5′-triphosphate,3′-diphosphate pyrophosphatase, an enzyme involved in the bacterial stringent response. Unique environments like the CF airway can drive functional adaptations, leading to shifts in metabolic profiles. These results have important clinical implications for CF, indicating that therapeutic measures may be more effective if used to change the respiratory environment, as opposed to shifting the taxonomic composition of resident microbiota.     

Production of Nitric Oxide in Loam Under Aerobic and Anaerobic Conditions

Measurements of gas flow through soil columns of loam from Kjettslinge, Uppland, Sweden, gave average NO production rates of 0.06 ± 0.01 ng of NO N g of soil⁻¹ min⁻¹ in aerobic conditions and 3.7 ± 0.6 ng of NO N g of soil⁻¹ min⁻¹ in anaerobic conditions at 25°C. Approximately 30% of the NO₃⁻ loss in anaerobic conditions was as NO. In aerobic conditions an equilibrium concentration for NO was found. Above this concentration there was uptake of NO. Autoclaved samples indicated that less than 10% of the NO production was abiological, and there was no abiological NO uptake. The NO production reached anaerobic rates at soil O₂ levels between 0.5 and 0.05%.     

Laboratory Study of Chemical Speciation of Mercury in Lake Sediment and Water under Aerobic and Anaerobic Conditions

Chemical speciation and partitioning of radiolabeled HgCl₂ were studied in model aquatic systems consisting of undisturbed eutrophic lake sediment and water in plastic cylinders. The cylinders were either gradually made anaerobic by a gentle flow of N₂-CO₂ or kept aerobic by air flow. The proportion of methylated ²⁰³Hg was significantly higher, in both water and sediment, in the anaerobic systems than in the aerobic systems. The composition and total concentration of fatty acids originating from bacterial phospholipids, as well as the concentration of vitamin B₁₂, including related cobalamins, were similar in sediments from the anaerobic and aerobic systems. Bacterial cell numbers were, on average, 3.6 times higher in the anaerobic water columns than in the aerobic ones. Volatilization of ²⁰³Hg occurred in all systems except in an autoclaved control and was of similar magnitudes in the anaerobic and aerobic systems. Incorporation of ²⁰³Hg into the sediment was significantly faster in the aerobic systems than in the anaerobic systems. These results suggest that episodes of anoxia in bottom waters and sediment cause an increase in net mercury methylation and, hence, an increase in bioavailable mercury.     

Comparative Studies of Glucose Catabolism by Escherichia coli Grown in a Complex Medium under Aerobic and Anaerobic Conditions

Escherichia coli HB101 was grown in complex medium under anaerobic and aerobic conditions. Cells prepared under these two different conditions were characterized by two-dimensional protein gel electrophoresis, by NMR measurements under identical (anaerobic) conditions, and by measuring the kinetics of glucose uptake and catabolite end-product appearance in the medium under identical anaerobic conditions. Specific rates of glucose uptake and end-product formation were significantly greater for the anaerobically grown cells, which also exhibited lower intracellular concentrations of sugar phosphates, nucleoside di-and triphosphates, UDPG, and NAD(H). Two-dimensional gel electrophoretic analyses reveal changes in the intracellular levels of proteins involved in pyruvate catabolism that have been observed previously for E. coli grown in minimal medium under aerobic and anaerobic conditions. Enzymes involved in the TCA cycle were not detected in cells grown aerobically or anaerobically in complex medium.     

High Individuality of Respiratory Bacterial Communities in a Large Cohort of Adult Cystic Fibrosis Patients under Continuous Antibiotic Treatment

BackgroundRoutine clinical diagnostics of CF patients focus only on a restricted set of well-known pathogenic species. Recent molecular studies suggest that infections could be polymicrobial with many bacteria not detected by culture-based diagnostics.ConclusionsThe high individuality in community composition and the lack of correlation to clinical host factors might be due to the continuous treatment with antibiotics. Since this is current practice for adult CF patients, the life-long history of the patient and the varying selection pressure on the related microbial communities should be a focus of future studies and its relation to disease progression. These studies should be substantially larger, providing more molecular information on the microbial communities complemented by detailed genetic assessment of the host.     

Reduction of Soluble and Insoluble Iron Forms by Membrane Fractions of Shewanella oneidensis Grown under Aerobic and Anaerobic Conditions

The effect of iron substrates and growth conditions on in vitro dissimilatory iron reduction by membrane fractions of Shewanella oneidensis MR-1 was characterized. Membrane fractions were separated by sucrose density gradients from cultures grown with O₂, fumarate, and aqueous ferric citrate as the terminal electron acceptor. Marker enzyme assays and two-dimensional gel electrophoresis demonstrated the high degree of separation between the outer and cytosolic membrane. Protein expression pattern was similar between chelated iron- and fumarate-grown cultures, but dissimilar for oxygen-grown cultures. Formate-dependent ferric reductase activity was assayed with citrate-Fe³⁺, ferrozine-Fe³⁺, and insoluble goethite as electron acceptors. No activity was detected in aerobic cultures. For fumarate and chelated iron-grown cells, the specific activity for the reduction of soluble iron was highest in the cytosolic membrane. The reduction of ferrozine-Fe³⁺ was greater than the reduction of citrate-Fe³⁺. With goethite, the specific activity was highest in the total membrane fraction (containing both cytosolic and outer membrane), indicating participation of the outer membrane components in electron flow. Heme protein content and specific activity for iron reduction was highest with chelated iron-grown cultures with no heme proteins in aerobically grown membrane fractions. Western blots showed that CymA, a heme protein involved in iron reduction, expression was also higher in iron-grown cultures compared to fumarate- or aerobic-grown cultures. To study these processes, it is important to use cultures grown with chelated Fe³⁺ as the electron acceptor and to assay ferric reductase activity using goethite as the substrate.     

Polymorphism of Glutathione S-Transferase M1 and P1 in Patients with Cystic Fibrosis and Chronic Respiratory Diseases

Polymorphism of GSTM1 and GSTP1 genes was studied in patients with cystic fibrosis (CF) and chronic bronchopulmonary diseases (CBPD) living in Bashkortostan. A combination of certain GSTM1 and GSTP1 genotypes accompanied by severe mutations inCFTRgene proved to intensify a pathologic process in respiratory organs of patients with CF; a combination of the normal GSTM1 and heterozygous I/V GSTP1 genotypes is the most favorable (OR = 4.49; ² = 11.53, P < 0.002). In patients with CBPD, a combination of the GSTM1null genotype and the homozygous GSTP1 V/V genotype is the most common (5.5% versus 1.3% in control; ² = 3.01, P = 0.08). The frequency of this genotype is highest in groups of patients with recurrent bronchitis (8.1%; P = 0.07; OR = 6.75) and bronchiectatic disease (BED) (9.1%, P > 0.10, OR = 7.65). A combination of the null GSTM1 andI/V GSTP1 genotypes was found in 40.0% of patients with chronic nonobstructive bronchitis (² = 4.87; P = 0.03; OR = 4.03). Among patients with BED, a proportion of individuals with the normal GSTM1 and I/V GSTP1 genotypes was increased (36.4% versus 19.4% in control). In patients with chronic obstructive pulmonary disease (COPD), the frequencies of the GSTM1 and GSTP1 genotype combinations virtually did not differ from those in the control group suggesting that COPD severity is not related to changes in activities of glutathione S-transferases M1 and P1.     

Focus: Antimicrobial Resistance: The Status of Carbapenem Resistance in Cystic Fibrosis: A Systematic Review and Meta-Analysis

Background: Antibiotic resistance in cystic fibrosis (CF) is a well-known phenomenon. However, the comprehensive epidemiological impact of antibiotic resistance in CF is not clearly documented. So, this meta-analysis evaluated the proportion rates of carbapenem resistance (imipenem, meropenem, and doripenem) in CF based on publication date (1979-2000, 2001-2010, and 2011-2021), continents, pathogens, and antimicrobial susceptibility testing (AST). Methods: We searched studies in PubMed, Scopus, and Web of Science (until April 2021). Statistical analyses were conducted using STATA software (version 14.0). Results: The 110 studies included in the analysis were performed in 25 countries and investigated 13,324 pathogens associated with CF. The overall proportion of imipenem, meropenem, and doripenem resistance in CF were 43% (95% CI 36-49), 48% (95% CI 40-57), 28% (95% CI 23-33), and 45% (95% CI 32-59), respectively. Our meta-analysis showed that trends of imipenem, meropenem, and doripenem-resistance had gradual decreases over time (1979-2021). This could be due to the limited clinical effectiveness of these antibiotics to treat CF cases over time. Among the opportunistic pathogens associated with CF, the highest carbapenem resistance rates were shown in Stenotrophomonas maltophilia, Burkholderia spp., Pseudomonas aeruginosa, and Staphylococcus aureus. The highest and lowest carbapenem resistance rates among P. aeruginosa in CF patients were shown against meropenem (23%) and doripenem (39%). Conclusions: We showed that trends of carbapenem resistance had decreased over time (1979-2021). This could be due to the limited clinical effectiveness of these antibiotics to treat CF cases over time. Plans should be directed to fight biofilm-associated infections and prevent the emergence of mutational resistance. Systematic surveillance for carbapenemase-producing pathogens in CF by molecular surveillance is necessitated.     

Reduced Bacterial Colony Count of Anaerobic Bacteria Is Associated with a Worsening in Lung Clearance Index and Inflammation in Cystic Fibrosis

Anaerobic bacteria have been identified in abundance in the airways of cystic fibrosis (CF) subjects. The impact their presence and abundance has on lung function and inflammation is unclear. The aim of this study was to investigate the relationship between the colony count of aerobic and anaerobic bacteria, lung clearance index (LCI), spirometry and C-Reactive Protein (CRP) in patients with CF. Sputum and blood were collected from CF patients at a single cross-sectional visit when clinically stable. Community composition and bacterial colony counts were analysed using extended aerobic and anaerobic culture. Patients completed spirometry and a multiple breath washout (MBW) test to obtain LCI. An inverse correlation between colony count of aerobic bacteria (n = 41, r = -0.35; p = 0.02), anaerobic bacteria (n = 41, r = -0.44, p = 0.004) and LCI was observed. There was an inverse correlation between colony count of anaerobic bacteria and CRP (n = 25, r = -0.44, p = 0.03) only. The results of this study demonstrate that a lower colony count of aerobic and anaerobic bacteria correlated with a worse LCI. A lower colony count of anaerobic bacteria also correlated with higher CRP levels. These results indicate that lower abundance of aerobic and anaerobic bacteria may reflect microbiota disruption and disease progression in the CF lung.     

The Effects of Ethanol on the Germination of Seeds of Japonica and Indica Rice (Oryza sativa L.) under Anaerobic and Aerobic Conditions

An examination was made of the effects of ethanol at 0.2–6.0%(v/v) on the germination, under aerobic conditions, of intactand dehusked seeds of indica rice (cv. Assam IV), which hadbeen harvested 14, 21 and 28 d after anthesis, and of the japonicarice (cv. Sasanishiki), which had been harvested 30 and 60 dafter anthesis. The inhibition of germination caused by dehuskingjaponica rice was overcome by 0.5–5% ethanol, with maximumgermination (frequently 100%) achieved at 3–5% (30 d afteranthesis) or 1–4.5% (60 d after anthesis) ethanol. Furtherincreases in the ethanol concentration reduced germination.The germination of dehusked indica rice was slightly inhibitedat 0.5 and 1% ethanol, whilst the promotion of germination by2% ethanol increased as the seeds matured. At all harvests germinationwas greatest at 3% ethanol, and at 5–6% ethanol germinationfell to 0%. Inhibition, no effect, or minimal stimulation ofthe germination of intact seeds of both japonica and indicarice by ethanol was observed at the concentrations examined.The absence of oxygen stimulated germination of dehusked japonicarice, but this germination was inhibited by ethanol. In contrastethanol had little or no effect on the failure of dehusked indicaseeds to germinate in anaerobic conditions. Thus ethanol treatmentmay help break the strong dormancy of dehusked seeds of indicaand japonica rice. The possible role of ethanol in stimulatinggermination in rice is discussed. Rice; Oryza sativa L.; seed germination; dehusking treatment; ethanol; indica; japonica; oxygen; dormancy; germination inhibition; seed formation     

Reductive Dechlorination of Trichloroethylene and Tetrachloroethylene under Aerobic Conditions in a Sediment Column

Biodegradation of trichloroethylene and tetrachloroethylene under aerobic conditions was studied in a sediment column. Cumulative mass balances indicated 87 and 90% removal for trichloroethylene and tetrachloroethylene, respectively. These studies suggest the potential for simultaneous aerobic and anaerobic biotransformation processes under bulk aerobic conditions.     

Phenotypic Characterization of Shewanella oneidensis MR-1 under Aerobic and Anaerobic Growth Conditions by Using Fourier Transform Infrared Spectroscopy and High-Performance Liquid Chromatography Analyses

Shewanella oneidensis is able to conserve energy for growth by reducing a wide variety of terminal electron acceptors during anaerobic respiration, including several environmentally hazardous pollutants. This bacterium employs various electron transfer mechanisms for anaerobic respiration, including cell-bound reductases and secreted redox mediators. The aim of this study was to develop rapid tools for profiling the key metabolic changes associated with these different growth regimes and physiological responses. Initial experiments focused on comparing cells grown under aerobic and anaerobic conditions. Fourier transform infrared (FT-IR) spectroscopy with cluster analysis showed that there were significant changes in the metabolic fingerprints of the cells grown under these two culture conditions. FT-IR spectroscopy clearly differentiated cells of S. oneidensis MR-1 cultured at various growth points and cells grown using different electron acceptors, resulting in different phenotypic trajectories in the cluster analysis. This growth-related trajectory analysis is applied successfully for the first time, here with FT-IR spectroscopy, to investigate the phenotypic changes in contrasting S. oneidensis cells. High-performance liquid chromatography (HPLC) was also used to quantify the concentrations of flavin compounds, which have been identified recently as extracellular redox mediators released by a range of Shewanella species. The partial least-squares regression (PLSR) multivariate statistical technique was combined with FT-IR spectroscopy to predict the concentrations of the flavins secreted by cells of S. oneidensis MR-1, suggesting that this combination could be used as a rapid alternative to conventional chromatographic methods for analysis of flavins in cell cultures. Furthermore, coupling of the FT-IR spectroscopy and HPLC techniques appears to offer a potentially useful tool for rapid characterization of the Shewanella cell metabolome in various process environments.Shewanella oneidensis, a Gram-negative dissimilatory metal-reducing bacterium, is able to conserve energy for growth by reducing a variety of terminal electron acceptors during aerobic and anaerobic respiration (24), including several environmentally hazardous pollutants (1). The terminal electron acceptors used during anaerobic respiration vary, ranging from nitrate, fumarate, trimethylamine N-oxide (TMAO), dimethyl sulfoxide (DMSO), and sulfur compounds to fuel cell anodes and various metals and metalloids, including insoluble metal oxides (5, 33, 34).There has been intense interest in the versatile metabolism of this bacterium and its potential to respire and bioremediate toxic environmental chemicals and metals, such as U(VI) and Cr(VI) (25, 43), under anoxic conditions. Riboflavin (RF), flavin mononucleotide (FMN), and flavin-adenine dinucleotide (FAD) were identified as the dominant electron shuttles secreted by a diversity of Shewanella cells and shown to mediate extracellular reduction of insoluble Fe(III) minerals and organic molecules, including azo dyes (23, 40). Field and Brady tested riboflavin and found that its presence during anaerobic reduction of azo dyes improves the overall kinetics of the reduction process (9). von Canstein et al. recently found that Shewanella cells are able to secrete flavins, FAD, FMN, and riboflavin as extracellular redox mediators and quantified these using high-performance liquid chromatography-mass spectrometry (HPLC-MS) (44). The experiments showed that the production profiles of these three chemicals were different under anaerobic and aerobic regimes, and this can be used to distinguish the two metabolic pathways with oxygen or fumarate as electron acceptors.Although we are gaining a deeper understanding of the genetic and biochemical basis of the diverse respiration pathways of this organism, supported by the recent availability of the complete genome sequence (14), complementary metabolomic approaches have not been used to identify or quantify the metabolic changes expected with major physiological shifts in this organism under contrasting growth regimes. Fourier transform infrared (FT-IR) spectroscopy was chosen for this study, as this method offers the advantage of minimal sample preparation, as well as being rapid, nondestructive, readily automatable, relatively inexpensive, and quantitative, compared with other metabolic profiling techniques (8, 12, 15, 35). The infrared absorbance spectra generated by FT-IR spectroscopy have been used to identify specific biochemical features and also provide a global biochemical “fingerprint” for mixed, complex samples (11, 27) in many research areas (10, 11). For instance, FT-IR spectroscopy has proved sensitive enough for analysis of the chemical composition of a single strain of Escherichia coli after exposure to ionic liquids (6), for functional genomics screening (22), for measuring abiotic perturbations in algae (39), and for characterization of microbial degradation pathways (16). We believe that this technique offers considerable potential for rapid differentiation of metabolic changes of bacteria responding to contrasting growth regimes in natural and engineered environments, although this remains to be demonstrated.The FT-IR spectra generated from microorganisms have very complex profiles that can be related back to biochemical components which one would expect to be detected in the samples. While some subtle quantitative differences can be observed between the spectra, there are few, if any, qualitative differences to be seen, and so it is almost impossible to interpret these data with the naked eye (19, 20, 45). Therefore, multivariate statistical techniques are needed to model the relationship between the phenotypic changes occurring in this organism during growth with the observations recorded by FT-IR spectroscopy.In the present study, we investigated the ability of FT-IR spectroscopy to analyze the S. oneidensis MR-1 cell metabolome and distinguish significant metabolic changes associated with anaerobic and aerobic growth conditions. Analyses were conducted directly on the cells for the endometabolome in assessing the metabolic fingerprint. Both unsupervised and supervised learning methods (viz., principal component analysis [PCA] [21] and discriminant function analysis [DFA] [26]) were used to identify any differences between the FT-IR spectra from cells grown under the two regimes, and the contributions of a range of biomolecules were elucidated. In addition to metabolic fingerprinting of whole cells by FT-IR, key components of the extracellular metabolome (the so-called exometabolome, or metabolic footprint) were also quantified by HPLC analysis. Here, riboflavin, FMN, and FAD in culture supernatants were quantified, and partial least-squares regression (PLSR) was used to identify correlations between the cell''s FT-IR spectra and flavin concentrations assessed using HPLC data. These studies show for the first time that FT-IR analyses can be used for rapid identification of metabolic shifts in both the intracellular and the extracellular metabolomes of S. oneidensis MR-1 cultures.     

Reductive Dechlorination of Trichloroethylene and Tetrachloroethylene under Aerobic Conditions in a Sediment Column

[This corrects the article on p. 2202 in vol. 60.].     

Clonal Dissemination,Emergence of Mutator Lineages and Antibiotic Resistance Evolution in Pseudomonas aeruginosa Cystic Fibrosis Chronic Lung Infection

Chronic respiratory infection by Pseudomonas aeruginosa is a major cause of mortality in cystic fibrosis (CF). We investigated the interplay between three key microbiological aspects of these infections: the occurrence of transmissible and persistent strains, the emergence of variants with enhanced mutation rates (mutators) and the evolution of antibiotic resistance. For this purpose, 10 sequential isolates, covering up to an 8-year period, from each of 10 CF patients were studied. As anticipated, resistance significantly accumulated overtime, and occurred more frequently among mutator variants detected in 6 of the patients. Nevertheless, highest resistance was documented for the nonmutator CF epidemic strain LES-1 (ST-146) detected for the first time in Spain. A correlation between resistance profiles and resistance mechanisms evaluated [efflux pump (mexB, mexD, mexF, and mexY) and ampC overexpression and OprD production] was not always obvious and hypersusceptibility to certain antibiotics (such as aztreonam or meropenem) was frequently observed. The analysis of whole genome macrorestriction fragments through Pulsed-Field Gel Electrophoresis (PFGE) revealed that a single genotype (clone FQSE-A) produced persistent infections in 4 of the patients. Multilocus Sequence typing (MLST) identified clone FQSE-A as the CF epidemic clone ST-274, but striking discrepancies between PFGE and MLST profiles were evidenced. While PFGE macrorestriction patterns remained stable, a new sequence type (ST-1089) was detected in two of the patients, differing from ST-274 by only two point mutations in two of the genes, each leading to a nonpreviously described allele. Moreover, detailed genetic analyses revealed that the new ST-1089 is a mutS deficient mutator lineage that evolved from the epidemic strain ST-274, acquired specific resistance mechanisms, and underwent further interpatient spread. Thus, presented results provide the first evidence of interpatient dissemination of mutator lineages and denote their potential for unexpected short-term sequence type evolution, illustrating the complexity of P. aeruginosa population biology in CF.     

Protease Inhibitors in Improvement of Plant Resistance to Pathogens and Insects

This review concerns the possibility of using plant inhibitors of proteolytic enzymes to improve plant resistance to insects and phytopathogens. The main argument in favor of this approach is that protease inhibitors are widespread in plant tissues and highly active with respect to various proteases of insects, bacteria, and fungi. Genetic engineering yields promising results in the field, as recent studies demonstrate. The main drawbacks of the approach and ways to improve its efficiency are discussed. Still, the approach has several advantages over the standard methods and is ecologically safe.__________Translated from Molekulyarnaya Biologiya, Vol. 39, No. 4, 2005, pp. 702–708.Original Russian Text Copyright © 2005 by Dunaevsky, Elpidina, Vinokurov, Belozersky.