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Corn and common bean have been cultivated together in Mesoamerica for thousands of years in an intercropping system called “milpa,” where the roots are intermingled, favoring the exchange of their microbiota, including symbionts such as rhizobia. In this work, we studied the genomic expression of Rhizobium phaseoli Ch24-10 (by RNA-seq) after a 2-h treatment in the presence of root exudates of maize and bean grown in monoculture and milpa system under hydroponic conditions. In bean exudates, rhizobial genes for nodulation and degradation of aromatic compounds were induced; while in maize, a response of genes for degradation of mucilage and ferulic acid was observed, as well as those for the transport of sugars, dicarboxylic acids and iron. Ch24-10 transcriptomes in milpa resembled those of beans because they both showed high expression of nodulation genes; some genes that were expressed in corn exudates were also induced by the intercropping system, especially those for the degradation of ferulic acid and pectin. Beans grown in milpa system formed nitrogen-fixing nodules similar to monocultured beans; therefore, the presence of maize did not interfere with Rhizobium–bean symbiosis. Genes for the metabolism of sugars and amino acids, flavonoid and phytoalexin tolerance, and a T3SS were expressed in both monocultures and milpa system, which reveals the adaptive capacity of rhizobia to colonize both legumes and cereals. Transcriptional fusions of the putA gene, which participates in proline metabolism, and of a gene encoding a polygalacturonase were used to validate their participation in plant–microbe interactions. We determined the enzymatic activity of carbonic anhydrase whose gene was also overexpressed in response to root exudates.

‘Patharnakh’ (PN) (Pyrus pyrifolia Burm. Nakai) and ‘Punjab Beauty’ (PB) [Pyrus communis L. × Pyrus pyrifolia Burm. (Nakai)] are leading low-chill pear cultivars of subtropics of India. Diurnal temperature and relative humidity during fruit harvest period is high which considerably affect the shelf life of fruits. Fruits of ‘PN’ and ‘PB’ pear harvested at physiological maturity were stored for 12 days at ambient temperature and effects of storage temperature on physical and qualitative parameters were studied. Both cultivars showed reduction in fruit weight and firmness, reducing sugars, sucrose, starch and pectin content. However, total soluble solids and juice acid content increased during storage. Sucrose synthase activity and sucrose content showed significant positive correlation in ‘PN’ cultivar. Activities of fruit softening enzymes such as polygalacturonase (PG) and cellulase was enhanced; whereas, pectinmethylesterase (PME) was reduced during storage. Fruit firmness was negatively correlated with PG in both the cultivars. In ‘PN’ cultivar, fruit firmness was positively correlated with cellulase and negatively with PME enzyme but reverse trend was observed in ‘PB’ cultivar. Fruit minerals content didn’t show any substantial disparities in both the cultivars during storage. ‘Patharnakh’ and ‘Punjab Beauty’ fruits maintain desirable quality parameters up to 6-9 days and 3-6 days, respectively, during storage at ambient conditions.

Summary: Pitanga fruit stands out for its exotic flavour and antioxidant properties. The objective of this work was to evaluate changes in the physical, chemical and biochemical variables of red pitanga variety, in four stages of development (green, yellow, orange and red) and associate them to the cell wall break down. Analysis of pH, titratable acidity, soluble solids, firmness, soluble pectin, pectinamethylesterase (PME), polygalacturonase (PG), cell wall swelling and microstructure were performed. pH and levels of soluble solids and soluble pectin increased, in addition to the cell wall swelling and reduction of firmness, throughout the development of pitanga. From the SEM, it was possible to observe the degradation of the fruit cell wall during ripening, suggesting mainly the degradation of pectic polysaccharides, verified by the solubilisation of these substances. PG and PME enzymes were not active, which suggests that other enzymes may be associated with the cell wall break down. [ABSTRACT FROM AUTHOR]

Summary: In addition to color, texture of 'laba' garlic can also change. To study texture properties of 'laba' garlic and their change mechanisms during pickling, texture, ultrastructures, membrane permeability, water status, wall polysaccharides contents, and enzyme activities of garlics in three color states (white, green, and yellow) were studied. The results showed that the firmness, fracturability, membrane permeability, malonaldehyde, protopectin, and chelator‐soluble pectin contents, and cellulase and polygalacturonase activities of garlic decreased significantly (P < 0.05), while the water, cellulose, and water‐soluble pectin contents, and pectin methylesterase (PME) activity increased after pickling. In addition, the more content of free water and less content of immobilised water were contained in 'laba' garlic than in fresh garlic owing to wall degradation and water translocation, especially in yellow garlic. In summary, texture changes in 'laba' garlic are mainly dependent on pectin composition, water status, and PME activity. [ABSTRACT FROM AUTHOR]

Biochemical and bio-catalytic properties of an enzyme are essential to evaluate its potential industrial applications in food, pharmaceutical, textile, paper and pulp. More specifically, identifying optimal pH and temperature, and their effects on the residual enzyme activity are of high priority in biochemical characterisation. Therefore, in this study, polygalacturonase (PGase) produced as an extracellular enzyme in an earlier study growing Bacillus subtilis on hazelnut shell hydrolysate was evaluated under varying pH and temperature for its stability. The optimal pH and temperature values of the enzyme were found as 7.0, and 50 °C, respectively. The enzyme Km and Vmax values were identified as 0.52 mg/mL and 3.27 μmol/min. The enzyme retained about 93 and 78% of its initial activity at 50 and 60 °C after 7 h, respectively. SDS-PAGE revealed a single activity band with molecular weight of 50 kDa. The half-life of PGase at 50 and 60 °C were 57.8 and 23 h, respectively. Thus, the results prove the potential of the B. subtilis pectinase produced using hazelnut shells in food processing e.g. extraction and clarification processes or treatment of pectic waste water. [ABSTRACT FROM AUTHOR]

Main conclusion: The downregulation of PpPG21 and PpPG22 expression in melting-flesh peach delays fruit softening and hinders texture changes by influencing pectin solubilization and depolymerization. The polygalacturonase (PG)-catalyzed solubilization and depolymerization of pectin plays a central role in the softening and texture formation processes in peach fruit. In this study, the expression characteristics of 15 PpPG members in peach fruits belonging to the melting flesh (MF) and non-melting flesh (NMF) types were analyzed, and virus-induced gene silencing (VIGS) technology was used to identify the roles of PpPG21 (ppa006839m) and PpPG22 (ppa006857m) in peach fruit softening and texture changes. In both MF and NMF peaches, the expression of PpPG1, 10, 12, 23, and 25 was upregulated, whereas that of PpPG14, 24, 35, 38, and 39 was relatively stable or downregulated during shelf life. PpPG1 was highly expressed in NMF fruit, whereas PpPG21 and 22 were highly expressed in MF peaches. Suppressing the expression of PpPG21 and 22 by VIGS in MF peaches significantly reduced PG enzyme activity, maintained the firmness of the fruit during the late shelf life stage, and suppressed the occurrence of the “melting” stage compared with the control fruits. Moreover, the downregulation of PpPG21 and 22 expression also reduced the water-soluble pectin (WSP) content, increased the contents of ionic-soluble pectin (ISP) and covalent-soluble pectin (CSP) and affected the expression levels of ethylene synthesis- and pectin depolymerization-related genes in the late shelf life stage. These results indicate that PpPG21 and 22 play a major role in the development of the melting texture trait of peaches by depolymerizing cell wall pectin. Our results provide direct evidence showing that PG regulates peach fruit softening and texture changes. [ABSTRACT FROM AUTHOR]

Pepper is one of the most important vegetable crops in China and has high economic value. However, the pepper fruit is easily softened and spoiled after harvest, which seriously affects its flavor, transportation, and economic value. In this study, we used pepper lines with different levels of storage resistance, A144 and A361, and performed physiological examination, transcriptomics, and metabolomics on them at 0 and 3 days after harvest in order to analyze their gene expression patterns and molecular regulatory mechanisms for storage tolerance. A total of 23,477 genes and 985 metabolites were identified. After comparing and analyzing each sample, we identified 7829 differentially expressed genes and 296 differential metabolites. We found that the genes such as ethylene-responsive transcriptional factor (ERFs), polygalacturonase (PG), cellulose synthase (CESA), abscisic acid insensitive (ABI), protein kinase 2 (SnRK2), and protein phosphatase 2C (PP2C) and metabolites such as phenylalanine and glycyl-tyrosine were differentially expressed between different storage times in the two materials. Through GO and KEGG enrichment analysis, we found that the differential genes were mainly enriched in carbohydrate metabolism, small molecule metabolism, and plant hormone signal transduction, and the differential metabolites were mainly enriched in flavonoid biosynthesis, glutathione metabolism, and cysteine and methionine metabolism pathways. This study provides a scientific basis for investigating the molecular mechanisms of storage tolerance and developing new pepper varieties with improved storage resistance. [ABSTRACT FROM AUTHOR]

Fungicide hormesis has implications for the application of fungicides to control plant diseases. We investigated the hormetic effects of the dicarboximide fungicide dimethachlone on mycelial growth and virulence of the necrotrophic plant pathogen Sclerotinia sclerotiorum. Dimethachlone at sublethal doses in potato dextrose agar (PDA) increased the mycelial growth of S. sclerotiorum. After the growthstimulated mycelia were subcultured on fresh PDA and inoculated on rapeseed leaves, increased mycelial growth and virulence were observed, indicating that hormetic traits were passed down to the next generation. Dimethachlone applied to leaves at 0.002 to 500 lg/ml stimulated virulence, with a maximum stimulation amplitude (MSA) of 31.4% for the isolate HLJ4, which occurred at 2 lg/ml. Dimethachlone-resistant isolates and transformants had a mean virulence MSA of 30.4%, which was significantly higher (P = 0.008) than the MSA for sensitive isolates (16.2%). Negative correlations were detected between MSA and virulence in the absence of any fungicide (r = -0.872, P < 0.001) and between MSA and mycelial growth on PDA (r = -0.794, P = 0.002). Studies on hormetic mechanisms indicated that dimethachlone had no significant effects on expression levels of three virulence-associated genes, that is, a cutinase-encoding gene SsCut, a polygalacturonase gene SsPG1, or an oxaloacetate acetylhydrolase gene SsOah1. The results will contribute to understanding hormesis and have implications for the judicious application of fungicides to control plant diseases. [ABSTRACT FROM AUTHOR]

'Patharnakh' (PN) (Pyrus pyrifolia Burm. Nakai) and 'Punjab Beauty' (PB) [Pyrus communis L. × Pyrus pyrifolia Burm. (Nakai)] are leading lowchill pear cultivars of subtropics of India. Diurnal temperature and relative humidity during fruit harvest period is high which considerably affect the shelf life of fruits. Fruits of 'PN' and 'PB' pear harvested at physiological maturity were stored for 12 days at ambient temperature and effects of storage temperature on physical and qualitative parameters were studied. Both cultivars showed reduction in fruit weight and firmness, reducing sugars, sucrose, starch and pectin content. However, total soluble solids and juice acid content increased during storage. Sucrose synthase activity and sucrose content showed significant positive correlation in 'PN' cultivar. Activities of fruit softening enzymes such as polygalacturonase (PG) and cellulase was enhanced; whereas, pectinmethylesterase (PME) was reduced during storage. Fruit firmness was negatively correlated with PG in both the cultivars. In 'PN' cultivar, fruit firmness was positively correlated with cellulase and negatively with PME enzyme but reverse trend was observed in 'PB' cultivar. Fruit minerals content didn't show any substantial disparities in both the cultivars during storage. 'Patharnakh' and 'Punjab Beauty' fruits maintain desirable quality parameters up to 69 days and 36 days, respectively, during storage at ambient conditions. [ABSTRACT FROM AUTHOR]

In this work, the polygalacturonase (TL-PG1) from the thermophilic fungus Thermomyces lanuginosus was heterologously produced for the first time in the yeast Komagataella phaffii. The TL-PG1 was successfully expressed under the control of the AOX1 promoter and sequentially purified by His-tag affinity. The purified recombinant pectinase exhibited an activity of 462.6 U/mL toward polygalacturonic acid under optimal conditions (pH 6 and 55 ˚C) with a 2.83 mg/mL and 0.063 μmol/minute for K m and V max , respectively. When used as supplementation for biomass hydrolysis, TL-PG1 demonstrated synergy with the enzymatic cocktail Ctec3 to depolymerize orange citrus pulp, releasing 1.43 mg/mL of reducing sugar. In addition, TL-PG1 exhibited efficiency in fabric bioscouring, showing potential usage in the textile industry. Applying a protein dosage of 7 mg/mL, the time for the fabric to absorb water was 19.77 seconds (ten times faster than the control). Adding the surfactant Triton to the treatment allowed the reduction of the enzyme dosage by 50% and the water absorption time to 6.38 seconds. Altogether, this work describes a new versatile polygalacturonase from T. lanuginosus with the potential to be employed in the hydrolysis of lignocellulosic biomass and bioscouring. • A polygalacturonase (TL-PG1) from Thermomyces lanuginosus was expressed in K. phaffii under the control of the AOX1 promoter. • The TL-PG1 was detected by SDS-PAGE and purified using the His-tag affinity column, exhibiting an activity of 462.6 U/mL. • Recombinant TL-PG1 demonstrated synergy with the enzymatic cocktail Ctec3 in the depolymerization of orange citrus pulp. • In textile bioscouring, TL-PG1 increased the hydrophilicity of the fabric displaying potential usage in this industry. [ABSTRACT FROM AUTHOR]

Polygalacturonases can be used to improve the processing of fruit juices and wines. This study aimed to produce, characterize and evaluate the potential application of polygalacturonase obtained from Lentinus tigrinus CCMB 553 in mango juice clarification. The fungal was isolated from the northeastern semi-arid region and fermented using Passiflora cincinnata bark as a substrate for solid state fermentation. The optimal conditions for enzyme production were obtained by applying the three-level factorial experimental design and were defined as 9 days and 30 °C for time and temperature, respectively. The optimal pH and temperature were determined by applying the Doehlert design and the results showed higher production between 45 and 60 °C and 4.0 and 5.5 for temperature and pH respectively. K m and V max of polygalacturonase from Lentinus tigrinus were 2.7 mg/mL and 12.86 μmol/min. The enzyme maintained 40 % residual activity after 30 min at 80 C. The influence of cations on enzyme activity was studied, and calcium ions seem to have a positive influence on enzyme activity, while Fe2+ ions have a negative influence. K+, Na+ and NH 4 + salts showed little influence on the polygalacturonase activity of Lentinus tigrinus. The application in the clarification of mango juice (Mangifera indica) using optimal conditions obtained resulted in a reduction of 45% of the viscosity and the clarification by about 79%. The results show that the polygalacturonase produced by Lentinus tigrinus CCMB 553 was efficiently applied in mango juice, improving the quality of the juice. • Polygalacturonase was produced by Lentinus tigrunus using Passiflora cincinnata bark as substrate for solid state fermentation. • Higher production of polygalacturonase occurred with 9 days of fermentation and 30 °C. • Polygalacturonase from Lentinus tigrinus maintained 40% of activity when submitted to 80 °C for 30 min. • The application in the clarification of mango juice resulted in a reduction of 45% of the viscosity and the clarification by about 79%. • Polygalacturonase produced by Lentinus tigrinus CCMB 553 was efficiently applied in mango juice, improving the quality of the juice. [ABSTRACT FROM AUTHOR]

The impact of prefermentative addition of five single-enzyme activities (pectin lyase, polygalacturonase, pectin methyl esterase, xylanase, and arabinase) on the phenolic content, colour characteristics, and volatile composition of grape musts resulting from pellicular maceration of Chardonnay, Arneis, Greco, and Falanghina white varieties was studied with the aim of enhancing aroma composition without negatively affecting colour perception. In addition, standard physicochemical parameters were determined. Pectin lyase, polygalacturonase, and arabinase enzymes reduced the must browning, when compared with untreated control, as reported by lower total polyphenol index, absorbance at 420 nm, and a* colour coordinate for all varieties tested. Regarding the volatile composition determined by solid-phase extraction and GC-MS analysis, variety effect was observed for the enzyme treatments studied. The concentration of free vanillin decreased significantly in these last three varieties using polygalacturonase and arabinase treatments whereas 4-vinylguaiacol increased in pectin lyase-treated samples. Free terpene compounds, such as furan linalool oxide, increased in Chardonnay and Falanghina varieties using polygalacturonase, xylanase, and arabinase for the second variety whereas pectin lyase for the first one. Contrarily, glycosylated terpenes, such us (Z)-8-hydroxylinalool, decreased when using pectin lyase and xylanase for Arneis; however, it also occurred for Falanghina using polygalacturonase treatment. The xylanase activity influenced mostly the volatile composition of the Arneis variety whereas arabinase did for Greco and Falanghina. The differences between enzyme-treated grape musts and control samples were less evident on the Chardonnay variety. Therefore, enzyme activity can affect the volatile composition of grape must differently depending on the target variety. [Display omitted] • Single-activity enzymes tested for pellicular maceration of four white varieties. • Pectinlyase, polygalacturonase and arabinase increased must yield-reducing browning. • All varieties had similar patterns for free volatiles using some enzyme treatments. • The variety effect prevails over enzyme activity mostly for glycosylated volatiles. • Xylanase affected mostly Arneis volatiles while arabinase for Greco and Falanghina. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel infrared (IR) inactivation method on polysaccharides (PG) was developed. • IR significantly reduced PG's activity by changing the PG's structure. • IR's heat energy & radiation energy destroyed PG's structure & its active sites. • IR's heat energy & radiation energy shortened the PG-substrate binding channel. • IR's thermal effect on PG's structure was more potent than the non-thermal effect. Food quality is greatly impacted by traditional heat methods for polygalacturonase (PG) inactivation; therefore, it's imperative to develop a novel infrared (IR) inactivation approach and identify its mechanism. Utilizing molecular dynamics (MD) simulation, this study verified the PG's activity, structure, active sites, and substrate channel under the single thermal and non-thermal effects of IR. PG activity was significantly reduced by IR, and structure was unfolded by increasing random coils (65.62 %) and decreasing β-sheets (29.11 %). MD data indicated that the relative locations of PG's active sites were altered by both IR effects, and the enzyme-substrate channel was shortened (10.53 % at 18 μm and 15.79 % at 80 °C). The thermal effect of IR on the inactivation of PG was significantly more pronounced than its non-thermal effect. This study unveiled the mechanism by which the infrared disrupted PG's activity, active sites, and substrate channels; thus, it expanded the infrared technique's efficacy in enzyme control. [ABSTRACT FROM AUTHOR]

Enzymatic degradation of plant biomass requires the coordinated action of various enzymes. In this study, the production of reducing sugars from pectic substrates and sugar beet pulp (SBP) was investigated and compared using commercial enzyme preparations, including M2, pectinase (E1), Viscozyme L (V-L) and L-40. V-L, a cellulolytic enzyme mix produced by Aspergillus sp. was further evaluated as the most robust enzyme cocktail with the strongest SBP degradation ability in terms of the release of monosaccharides, methanol, and acetate from SBP. Mass-spectrometry-based proteomics analysis of V-L revealed 156 individual proteins. Of these, 101 proteins were annotated as containing a carbohydrate-active enzyme module. Notably, of the 50 most abundant proteins, ca. 44 % were predicted to be involved in pectin degradation. To reveal the role of individual putative key enzymes in pectic substrate decomposition, two abundant galacturonases (PglA and PglB), were heterologously expressed in Pichia pastoris and further characterized. PglA and PglB demonstrated maximum activity at 57 °C and 68 °C, respectively, and exhibited endo-type cleavage patterns towards polygalacturonic acid. Further studies along this line may lead to a better understanding of efficient SBP degradation and may help to design improved artificial enzyme mixtures with lower complexity for future application in biotechnology. [ABSTRACT FROM AUTHOR]

Abstract Background Polygalacturonase (PG), as an important hydrolase participating in the degradation of pectin, plays an important role in softening process of fruit. However, information on PG gene family in pear genome and the specific member involved in fruit softening is still rudimentary. Results In this study, a total of 61 PG genes, which could be divided into six subclasses, were identified from the pear genome with diverse chromosome locations, gene structures, motifs and cis-acting elements. Most PbrPGs were derived from WGD/segmental duplication blocks, and purifying selection was the main driving force for their expansion. The expression profiles of PbrPGs in pear were tissue/development-stage/cultivar-dependent. During ‘Housui’ pear storage, associated with the reduction of firmness was the accumulation of PG activity. Totally, 28 PbrPGs were expressed during fruit storage, which could be classified into five categories based on different expression patterns; most demonstrated an increased trend. Of these, PbrPG6 were proposed to account for pear softening in combination of the phylogenetic and correlation analysis among firmness, PG activity and PbrPGs. By constructing the silencing vector, a higher firmness was observed in PbrPG6-silenced fruit when compared with that of the control (empty vector). In a further study, we found that the expression of PbrPG6 was regulated by postharvest 1-MCP/ethrel treatment, and several PbrERFs might function in this process. Conclusions We identified 61 PbrPG genes from pear genome; of these, PbrPG6 was involved in fruit softening process; furthermore, the expression of PbrPG6 might be under the control of PbrERF. This study provides a foundation for future work aimed at elucidating the molecular mechanism underlying pear softening.

Abstract Background The hypersensitive defense response (HR) in plants is a fast, localized necrotic response around the point of pathogen ingress. HR is usually triggered by a pathogen recognition event mediated by a nucleotide-binding site, leucine-rich repeat (NLR) protein. The autoactive maize NLR gene Rp1-D21 confers a spontaneous HR response in the absence of pathogen recognition. Previous work identified a set of loci associated with variation in the strength of Rp1-D21-induced HR. A polygalacturonase gene homolog, here termed ZmPGH1, was identified as a possible causal gene at one of these loci on chromosome 7. Results Expression of ZmPGH1 inhibited the HR-inducing activity of both Rp1-D21 and that of another autoactive NLR, RPM1(D505V), in a Nicotiana benthamiana transient expression assay system. Overexpression of ZmPGH1 in a transposon insertion line of maize was associated with suppression of chemically-induced programmed cell death and with suppression of HR induced by Rp1-D21 in maize plants grown in the field. Conclusions ZmPGH1 functions as a suppressor of programmed cell death induced by at least two autoactive NLR proteins and by two chemical inducers. These findings deepen our understanding of the control of the HR in plants.

Abstract Backgroud Horizontal gene transfer and gene duplication are two major mechanisms contributing to the evolutionary adaptation of organisms. Previously, polygalacturonase genes (PGs) were independently horizontally transferred and underwent multiple duplications in insects (e.g., mirid bugs and beetles). Here, we chose three phytozoophagous mirid bugs (Adelphocoris suturalis, A. fasciaticollis, A. lineolatus) and one zoophytophagous mirid bug (Nesidiocoris tenuis) to detect whether the duplication, molecular evolution, and expression levels of PGs were related to host range expansion in mirid bugs. Results By RNA-seq, we reported 30, 20, 19 and 8 PGs in A. suturalis, A. fasciaticollis, A. lineolatus and N. tenuis, respectively. Interestingly, the number of PGs was significantly positive correlation to the number of host plants (P = 0.0339) in mirid bugs. Most PGs (> 17) were highly expressed in the three phytozoophagous mirid bugs, while only one PG was relatively highly expressed in the zoophytophagous mirid bug. Natural selection analysis clearly showed that a significant relaxation of selection pressure acted on the PGs in zoophytophagous mirid bugs (K = 0.546, P = 0.0158) rather than in phytozoophagous mirid bugs (K = 1, P = 0.92), suggesting a function constraint of PGs in phytozoophagous mirid bugs. Conclusion Taken together with gene duplication, molecular evolution, and expression levels, our results suggest that PGs are more strictly required by phytozoophagous than by zoophytophagous mirid bugs and that the duplication of PGs is associated with the expansion of host plant ranges in mirid bugs.

Fruit splitting is one of main problems extensively observed in citrus-growing area located in the northern parts of Iran. In order to investigate the effect of 2,4-D and GA3 on incidence of fruit splitting in Thompson ‘navel’ orange, an experiment, as a factorial arrangement in a randomized complete block design (RCBD) with three replications, was carried out in two consecutive years of 2016 and 2017. The main factors of this experiment included timing of spray at different growth stages (full bloom, petal fall, and June drop), 2, 4-D (0, 10, 20 mg L–1), and GA3 (0, 50, and 100 mg L–1). In the end of experiment, the characteristics including fruit length, fruit diameter, rind thickness, cellulase and polygalacturonase activities, total soluble solid, percentage of split fruit, and fruit yield were measured. Results showed that using 2, 4-D and GA3 not only decreased the rate of fruit splitting but also increased fruit yield as compared to controls. The highest fruit length, fruit diameter, rind thickness, total soluble solid and the lowest activities of cellulase and polygalacturonase were obtained using 100 mg L–1 GA3 and 20 mg L–1 2, 4 D during the full bloom. In general, the results revealed that using 2, 4-D and GA3 during the full bloom increased fruit yield while reduced fruit splitting and maintained the qualitative characteristics of Thompson ‘navel’ orange.

Ultrasound-assisted enzymatic maceration (UAEM) has gained considerable interest in the fruit juice industry, owing to its potential to increase juice yield and content of polyphenols while simultaneously saving time and energy. In this study, the effects of UAEM (ultrasonic probe, 20 kHz, 21 W*cm−2 and 33 W*cm−2) on pectin degradation in a continuous circulation system were investigated over 60 and 90 min. Main pectinolytic enzymes activities of (polygalacturonase, pectin lyase and pectin methylesterase) of a commercial enzyme preparation were examined for individual synergistic effects with US. Pectin hydrolysis by UAEM differed significantly compared to treatment with ultrasound or enzymes alone regarding the profile of degradation products compared to treatment with ultrasound or enzymes alone. Ultrasound fragmented pectin to less branched oligomers of medium molecular weight (Mp approx. 150 kDa), which were further degraded by pectinolytic activities. The low molecular weight fraction (

The objective of the present study was to evaluate the physical and chemical changes, pectinases activity, and cell wall pectin in melon varieties Acidulus (access 16), Momordica (access 2), Inodorus (cv. ‘Iracema’) and Cantalupensis (cv. ‘Olympic’), in the relation of ripening degree at harvest. Melon fruits were planted and evaluated with different ripening degree at harvest, from 15 to 35 days after anthesis (DAA). The fruits, arranged in a completely randomized design, had been evaluated on the harvest days to physical and chemical characteristics. We evaluate pectin methylesterase, polygalacturonase, beta-galactosidase, and pectin contents (water-soluble, chelate soluble, and sodium carbonate soluble). The ideal harvest for each melon was, 35 days after anthesis for cv ‘Iracema’, 30 days after anthesis for cv. ‘Olympic’, 30 days after anthesis for access 16, and 20 days after anthesis for access 2. High pulp firmness of access 16 is associated with the high levels of sodium carbonate soluble pectin and low levels of polygalacturonase and beta-galactosidase activity. Momordica melon fruit cracking is related to the high levels of pectinases activity, as well as pectin degradation.

SUMMARY: Regulating plant architecture is a major goal in current breeding programs. Previous studies have increased our understanding of the genetic regulation of plant architecture, but it is also essential to understand how organ morphology is controlled at the cellular level. In the cell wall, pectin modification and degradation are required for organ morphogenesis, and these processes involve a series of pectin‐modifying enzymes. Polygalacturonases (PGs) are a major group of pectin‐hydrolyzing enzymes that cleave pectin backbones and release oligogalacturonides (OGs). PG genes function in cell expansion and separation, and contribute to organ expansion, separation and dehiscence in plants. However, whether and how they influence other cellular processes and organ morphogenesis are poorly understood. Here, we characterized the functions of Arabidopsis PG45 (PG45) in organ morphogenesis using genetic, developmental, cell biological and biochemical analyses. A heterologously expressed portion of PG45 cleaves pectic homogalacturonan in vitro, indicating that PG45 is a bona fide PG. PG45 functions in leaf and flower structure, branch formation and organ growth. Undulation in pg45 knockout and PG45 overexpression leaves is accompanied by impaired adaxial–abaxial polarity, and loss of PG45 shortens the duration of cell proliferation in the adaxial epidermis of developing leaves. Abnormal leaf curvature is coupled with altered pectin metabolism and autogenous OG profiles in pg45 knockout and PG45 overexpression leaves. Together, these results highlight a previously underappreciated function for PGs in determining tissue polarity and regulating cell proliferation, and imply the existence of OG‐based signaling pathways that modulate plant development. Significance Statement: Polygalacturonases are pectin‐degrading enzymes that influence cell expansion and adhesion in plants, but how they function in leaf development is poorly understood. We discovered that changing the expression of POLYGALACTURONASE45 alters leaf curvature and influences leaf cell shape and proliferation, as well as the production of pectin fragments, in Arabidopsis thaliana. These results help us understand the connections between pectin degradation and the control of leaf shape, an important agronomic trait. [ABSTRACT FROM AUTHOR]

A total of 13 Actinomycetes strains were isolated from 70 soil samples collected from five locations across the Jeddah Province, while the other two locations located in Baljurashi province of Saudi Arabia. All 13 isolates were purified and subjected to enzymatic screening and antibacterial assays. The results indicated that two of these isolates (AC45 and AC69) produced both enzymes and exerted some antibacterial activity. Isolate AC45 produced more amylase and polygalacturonase (697.8 and 1498.59 units/ml, respectively) than isolate AC69; however, AC69 secreted more lipase than AC45 (6957 and 22127 unit/ml, respectively). Furthermore, both AC45 and AC69 exhibited good antibacterial activity against Staphylococcus aureus, Staphylococcus epidermidis, and Bacillus subtilis. The two isolates were identified using their 16S rRNA sequences, and the results suggest that isolate AC45 shares 99.71% similarity with Streptomyces lavenduligriseus and isolate AC69 shares 99% similarity with Streptomyces sp. [ABSTRACT FROM AUTHOR]

The extraction, purification, and characterization of PME and PG were studied for lemon fruit. Enzymes were partially purified by anion-exchange chromatography using UNOsphere™ Q anion exchanger for lemon PME and DEAE Cellulose anion exchanger for lemon PG. A single band with a fold purity of 20.95 and 15.75 for PME and PG respectively was observed on SDS-PAGE. Molecular weights of partially purified fractions of PME and PG as exhibited by SDS-PAGE were 48 kDa and 95 kDa respectively. Optimum pH and temperature of partially purified lemon PME and PG were pH 9, pH 5 and 45 °C. The crude PME and PG extracts exhibited D-values of 120.57–63.79 and 185.72–29.18 min; Z-values of 15.11 and 16.50 °C; and activation energies (Ea) of 58.23 and 57.18 kJ/mol, respectively. The enzyme stability was not significantly influenced by the fruit matrix as reflected by Z and Ea values. D and Z-values of both the enzymes and microorganisms should be considered while designing thermal treatments to obtain a product with better shelf life. [ABSTRACT FROM AUTHOR]

In Baja California, Fusarium oxysporum f. sp. lycopersici (Fol) is the causal agent of vascular wilt of tomato; however, the races present in the state remain unknown. The objective of this work was to isolate and identify Fusarium spp. and to validate a multiplex-PCR system to identify strains Fol and at the race level. Sixty symptomatic plants were collected, of which 45 isolates were obtained. When analyzed microscopically, it was confirmed that 44 corresponded to Fusarium spp. The use of the sp13 and sp23 oligonucleotide pairs that amplified the pgx4 and pg1 polygalacturonase genes, respectively, indicated the presence of Fol races 1 and 3 in the area. Sequence analysis of the elongation factor of the 1α translation (TEF1-α) of representative strains served to confirm its identity and the presence of Fol and F. solani in tomato plants with symptoms of vascular wilt. Finally, a RAPD analysis showed that the oligonucleotide OPA-11, generates a specific banding pattern in Fol race 1, so it could be used as a quick way to identify them. [ABSTRACT FROM AUTHOR]

In a previous study, we reported that ethylene treatment facilitated boil‐peeling in persimmons and in several other fruits; however, the mechanism underlying the facilitating effect of ethylene was not examined in detail. Thus, in this study, we investigated the effect of ethylene treatment on the peel characteristics of persimmons, that facilitated boil‐peeling, using chemical, genomic, and histochemistry analyses. The results of the study showed that the ethylene‐related genes, DK‐ACS1 and DK‐ACO2, and the pectinase‐active gene DKPG were not expressed, even though a minor increase in ethylene generation was observed after ethylene treatment. Conversely, significant accumulation of toluidine blue O and ruthenium red dyes were observed in the sarcocarp and exocarp of the fruits, indicating an increase in the quantity of polysaccharides, including pectic substances, at the site. The results also indicate that the increased cellulase activity observed in the pericarp of the fruits may be due to the aging of the fruits, and not necessarily as a result of ethylene treatment. Furthermore, ethylene treatment increased the quantity of polysaccharides, including pectic substances, directly below the pericarp, which caused the dissolution of the site, resulting in peeling. This study provides new insights on the effect of ethylene on boil‐peeling in persimmons and provides a foundation for future research studying the effect of heat treatment in the peeling of fruits or tomato. [ABSTRACT FROM AUTHOR]

Ginkgo biloba flavonoids are important natural bioactive compounds with strong physiological effects. To develop an eco‐friendly and effective method for extracting flavonoids from plants, a microbial method involving lignocellulose‐degrading bacterial enzymes was developed to improve flavonoid extraction from Ginkgo biloba leaves. In this study, a newly isolated bacterial strain, Paenarthrobacter sp. S1.3, was employed for the fermentation processing of Ginkgo biloba leaf powder. The enzymatic characteristics of xylanase, CMCase, polygalacturonase, and β‐glucosidase from Paenarthrobacter sp. S1.3 were also investigated. The major fermentation parameters for the microbial extraction of Ginkgo biloba flavonoids were optimized using response surface methodology. Under optimal conditions (30.6 °C, initial pH 7.6, and fermentation time 25 h), a total flavonoid yield of 34.15 ± 0.52 mg g−1 dry weight was obtained, which was 2.11 fold and 1.42 fold higher than the yields obtained from the unfermented and ethanol extraction methods, respectively. The optimized results also suggest that the polygalacturonase and β‐glucosidase might play an important role in flavonoid extraction. Fermentation utilizing lignocellulose‐degrading bacteria was a feasible green approach to improve the extraction of natural compounds from plants. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

To investigate the changes in polygalacturonase (PG) and pectin methyl esterase (PME) activity of dudaim melon (Cucumis melo Group Dudaim), the plants of three cultivars, 'Zangi-Abad', 'Kermanshah' and 'Kangavar', were planted in open-field. Female flowers were labeled at anthesis, and fruits were harvested at two maturity stages corresponding to 21 and 28 days after anthesis (DAA). Harvested fruits were stored at 5 or 13 °C for three weeks and firmness, ethylene production, and PG and PME activities were assayed during storage. In all three cultivars at most times during storage, PME activity of early-harvested fruits (21 DAA) was greater than in late-harvested fruits (28 DAA). Conversely, in late-harvested fruits this parameter did not fluctuate significantly during storage. In early-harvested fruits, PME activity decreased, whereas in some treatments (e.g., early-harvested 'Zangi-Abad' fruits stored at 13 °C) the activity of this enzyme increased. In general, PG activity in early-harvested fruits increased up to the 14th day (in 'Zangi-Abad' and 'Kermanshah') or 7th day (in 'Kangavar') of storage and then decreased until the end of storage. 'Kangavar' fruits behaved differently compared to the other two cultivars in the activity of the two enzymes measured. According to the results of this study, in dudaim fruits, PG and PME activities depend on the time of fruit harvest (i.e., number of days after anthesis), storage temperature, and storage duration. [ABSTRACT FROM AUTHOR]

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Background: Pectin plays a role in the recalcitrance of plant biomass by affecting the accessibility of other cell wall components to enzymatic degradation. Elimination of pectin consequently has a positive impact on the saccharification of pectin-rich biomass. This work thus focused on the behaviour of different pectin-degrading enzymes in the presence of low (5%) to high (35%) solid loading of lemon peel. Results: High solid loading of lemon peel affected pectin solubilisation differently depending on the pectinase used. Pectin lyase was less sensitive to a reduction of water content than was a mixture of endopolygalacturonase and pectin methylesterase, regardless of whether or not the latter's mode of action is processive or not. Marked changes in water mobility were observed along with enzymatic degradation depending on the enzyme used. However, the pectin lyase resulted in less pronounced shifts in water distribution than polygalacturonase–pectin methylesterase mixtures. At similar pectin concentration, pectin solutions hindered the diffusion of hydrolases more than the solid substrate. This can be attributed to the high viscosity of the highly concentrated pectin solutions while the solid substrate may provide continuous diffusion paths through pores. Conclusions: The increase in solid substrate loading reduced the efficiency of pectin-degrading enzymes catalysing hydrolysis more significantly than those catalysing β-elimination. LF-NMR experiments highlighted the impact of solid loading on water mobility. Compared to other enzymes and whatever the solid loading, pectin lyase led to longer relaxation times linked with the most destructuration of the solid substrate. This new information could benefit the biorefinery processing of pectin-rich plant material when enzymes are used in the treatment. [ABSTRACT FROM AUTHOR]

Background: Plant cell walls are the main physical barrier encountered by pathogens colonizing plant tissues. Alteration of cell wall integrity (CWI) can activate specific defenses by impairing proteins involved in cell wall biosynthesis, degradation and remodeling, or cell wall damage due to biotic or abiotic stress. Polygalacturonase (PG) depolymerize pectin by hydrolysis, thereby altering pectin composition and structures and activating cell wall defense. Although many studies of CWI have been reported, the mechanism of how PGs regulate cell wall immune response is not well understood. Results: Necrosis appeared in leaf tips at the tillering stage, finally resulting in 3–5 cm of dark brown necrotic tissue. ltn-212 showed obvious cell death and accumulation of H2O2 in leaf tips. The defense responses were activated in ltn-212 to resist bacterial blight pathogen of rice. Map based cloning revealed that a single base substitution (G-A) in the first intron caused incorrect splicing of OsPG1, resulting in a necrotic phenotype. OsPG1 is constitutively expressed in all organs, and the wild-type phenotype was restored in complementation individuals and knockout of wild-type lines resulted in necrosis as in ltn-212. Transmission electron microscopy showed that thicknesses of cell walls were significantly reduced and cell size and shape were significantly diminished in ltn-212. Conclusion: These results demonstrate that OsPG1 encodes a PG in response to the leaf tip necrosis phenotype of ltn-212. Loss-of-function mutation of ltn-212 destroyed CWI, resulting in spontaneous cell death and an auto-activated defense response including reactive oxygen species (ROS) burst and pathogenesis-related (PR) gene expression, as well as enhanced resistance to Xanthomonas oryzae pv. oryzae (Xoo). These findings promote our understanding of the CWI mediated defense response. [ABSTRACT FROM AUTHOR]

Pectin, the major non-cellulosic component of primary cell wall can be degraded by polygalacturonases (PGs) and pectin methylesterases (PMEs) during pathogen attack on plants. We characterized two novel enzymes, VdPG2 and VdPME1, from the fungal plant pathogen Verticillium dahliae. VdPME1 was most active on citrus methylesterified pectin (55–70%) at pH 6 and a temperature of 40 °C, while VdPG2 was most active on polygalacturonic acid at pH 5 and a temperature of 50 °C. Using LC-MS/MS oligoprofiling, and various pectins, the mode of action of VdPME1 and VdPG2 were determined. VdPME1 was shown to be processive, in accordance with the electrostatic potential of the enzyme. VdPG2 was identified as endo -PG releasing both methylesterified and non-methylesterified oligogalacturonides (OGs). Additionally, when flax roots were used as substrate, acetylated OGs were detected. The comparisons of OGs released from Verticillium -susceptible and partially resistant flax cultivars identified new possible elicitor of plant defence responses. [Display omitted] • Heterologous expression of two novel pectin degrading enzymes from Verticillium dahliae. • Mode of action determined by LC-MS/MS oligogalacturonides (OGs) profiling. • Computational approaches reveal PME processivity • OGs produced from Verticillium-susceptible or partially resistant flax cultivars differ [ABSTRACT FROM AUTHOR]

The objective of the present study was to evaluate the physical and chemical changes, pectinases activity, and cell wall pectin in melon varieties Acidulus (access 16), Momordica (access 2), Inodorus (cv. 'Iracema') and Cantalupensis (cv. 'Olympic'), in the relation of ripening degree at harvest. Melon fruits were planted and evaluated with different ripening degree at harvest, from 15 to 35 days after anthesis (DAA). The fruits, arranged in a completely randomized design, had been evaluated on the harvest days to physical and chemical characteristics. We evaluate pectin methylesterase, polygalacturonase, beta-galactosidase, and pectin contents (water-soluble, chelate soluble, and sodium carbonate soluble). The ideal harvest for each melon was, 35 days after anthesis for cv 'Iracema', 30 days after anthesis for cv. 'Olympic', 30 days after anthesis for access 16, and 20 days after anthesis for access 2. High pulp firmness of access 16 is associated with the high levels of sodium carbonate soluble pectin and low levels of polygalacturonase and beta-galactosidase activity. Momordica melon fruit cracking is related to the high levels of pectinases activity, as well as pectin degradation. [ABSTRACT FROM AUTHOR]

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Apple is a fruit with numerous nutrient content alongised high levels of harvest and consumption. The Manalagi is one of the varieties grown in Indonesia,characterized by a yellowish green coloration, sweet taste, as well as easy rot and damage potentials. Hence, many people have encouraged the need to process raw samples into processed juice products. This practice raises the sale value and prolongs the shelflife. However, the apple juice have a major challenge of easy browning and turbidity, resulting from the pectin content. Furthermore, removal is harder due to turbity, exceptthrough enzymatic depectination, with the pectinase enzymes, particularly pectinesterase (PE) and polygalacturonase (PG). The presence of these materials in the juice mixture leads to inherent pectin degradation into smaller fractions and consequently ensures clarity. In addition, the research involved Completely Randomized Factorial Design (CRFD) with two factors, including enzyme concentration (0.5% and 1%) and PG:PE ratio (1: 5, 1: 2, 1: 1, 2: 1; 5 : 1). Therefore, the data obtained were analyzed using two way ANOVA with 5% significance level. The variance analysis result showed the effect of concentration on pH and transmittance value, while the ratio influences Total Soluble Solid (TSS) and transmittance value. In addition, both variables collectively affect pH and viscosity values. The best treatment for manalagi apple juice clarification was obtained with 0.5% concentration samples and PG: PE ratio 5:1.

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For the bacterial source, Koyulhisar (Sivas, Turkey) apple orchard soil samples were used. Obtained isolates were identified at the species level by partial protein- and 16S rRNA gene sequence homology All of them were determined to be Bacillus clausii. Cultures were prepared with these isolates and after removing the cells, the proteins in the upper fluid were precipitated with the help of an organic solvent. While performing pectinase screening, it was noticed that an existing protease digested other proteins. This proteolytic activity was eliminated by increasing the incubation temperature to 55oC. Four different pectinase activities, polygalacturonase, pectin lyase, pectate lyase, and pectin methylesterase, were then demonstrated. Four protein bands corresponding to these activities visualised by SDS-PAGE were 80 kDa, 58 kDa, 46 kDa and ~ 28 kDa, respectively. Spectroscopic methods were employed for the identification of the enzymes. The smallest protein band (28 kDa) was found to be pectin methylesterase. Km and Vmax values of this enzyme were 0.4 and 217U, respectively. [ABSTRACT FROM AUTHOR]

Corynespora leaf spot (CLS) is one of the most important diseases in sesame and is caused by a fungal pathogen, Corynespora cassiicola. In this study, we investigated the role of cell‐wall‐degrading enzymes (CWDEs) in the process of pathogen infection and aimed to identify the enzyme that exerts positive effect. Corynespora cassiicola was inoculated in liquid culture and in sesame leaf. At 7 days postinoculation, CWDEs including polygalacturonase (PG), cellulase (CL), neutral xylanase (NEX) and laccase (LC) were detected in the supernatant and leaf extracts inoculated with Corynespora cassiicola. The result showed that the activities of LC and NEX were higher in liquid culture, while the activities of CL and PG were lower. In the sesame leaf infected by Corynespora cassiicola, the activity of NEX was the highest, those of CL and LC were the second highest and that of PG was the weakest, which indicated that NEX was the key enzyme in the process of sesame infection by Corynespora cassiicola. Secondly, the activities of the CWDEs secreted by Corynespora cassiicola were disparate in different sesame varieties. CWDEs activities of cultivar Jz were generally higher than cultivar Hn, and the activity change curve of Jz was also steeper than that of Hn. This indicates that the resistance mechanism of Hn may inhibit the activities of CWDEs and that the appearance and expansion of leaf necrosis spot is related to the comprehensive accumulation and action of various CWDEs. This is the first report investigating the association between CWDEs and pathogenesis of Corynespora cassiicola, causing Corynespora leaf spot in sesame. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agricultural Chemistry & Biotechnology is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Fruit splitting is one of main problems extensively observed in citrus-growing area located in the northern parts of Iran. In order to investigate the effect of 2,4-D and GA3 on incidence of fruit splitting in Thompson navel orange, an experiment, as a factorial arrangement in a randomized complete block design (RCBD) with three replications, was carried out in two consecutive years of 2016 and 2017. The main factors of this experiment included timing of spray at different growth stages (full bloom, petal fall, and June drop), 2, 4-D (0, 10, 20 mg L-1), and GA3 (0, 50, and 100 mg L-1). In the end of experiment, the characteristics including fruit length, fruit diameter, rind thickness, cellulase and polygalacturonase activities, total soluble solid, percentage of split fruit, and fruit yield were measured. Results showed that using 2, 4-D and GA3 not only decreased the rate of fruit splitting but also increased fruit yield as compared to controls. The highest fruit length, fruit diameter, rind thickness, total soluble solid and the lowest activities of cellulase and polygalacturonase were obtained using 100 mg L-1 GA3 and 20 mg L-1 2, 4 D during the full bloom. In general, the results revealed that using 2, 4-D and GA3 during the full bloom increased fruit yield while reduced fruit splitting and maintained the qualitative characteristics of Thompson navel orange. [ABSTRACT FROM AUTHOR]

Summary: The biosynthesis and modification of cell wall composition and structure are controlled by hundreds of enzymes and have a direct consequence on plant growth and development. However, the majority of these enzymes has not been functionally characterised.Rice mutants with leaf‐rolling phenotypes were screened in a field. Phenotypic analysis under controlled conditions was performed for the selected mutant and the relevant gene was identified by map‐based cloning. Cell wall composition was analysed by glycome profiling assay.We identified a photo‐sensitive leaf rolling 1 (psl1) mutant with 'napping' (midday depression of photosynthesis) phenotype and reduced growth. The PSL1 gene encodes a cell wall‐localised polygalacturonase (PG), a pectin‐degrading enzyme. psl1 with a 260‐bp deletion in its gene displayed leaf rolling in response to high light intensity and/or low humidity. Biochemical assays revealed PG activity of recombinant PSL1 protein. Significant modifications to cell wall composition in the psl1 mutant compared with the wild‐type plants were identified. Such modifications enhanced drought tolerance of the mutant plants by reducing water loss under osmotic stress and drought conditions.Taken together, PSL1 functions as a PG that modifies cell wall biosynthesis, plant development and drought tolerance in rice. [ABSTRACT FROM AUTHOR]

Polygalacturonase (PG) is a hydrolase that participates in pectin degradation, pod shattering and fruit softening. Here, we identified 2786 PG genes across 54 plants, which could be divided into three groups. Evolutionary analysis suggested that PG family originated from the charophyte green algae, and Subgroups A2–A4 evolved from the Subgroup A1 after the tracheophyte–angiosperm split. Whole-genome duplication was the major force leading to PG gene expansion. Interestingly, the PG genes continuously expanded in eudicots, whereas it contracted in monocots after the eudicot–monocot split. PG genes in Group A are expressed at high levels in floral organs, whereas genes in Groups B and C are expressed at high levels in various tissues. Moreover, three BnaPG15 members were found for their potential possibility in pod shattering in Brassica napus. Our results provide new insight into the evolutionary history of PG family, and their potentially functional role in plants. • 2786 PG genes were identified across 54 plants, which could be divided into three groups. • Whole-genome duplication was the major force leading to PG gene expansion in land plants. • PG genes in Group A are expressed at high levels in floral organs, whereas genes in Groups B and C are expressed at high levels in various tissues. • Three PG15 members were found for their potential possibility in pod shattering in Brassica napus. [ABSTRACT FROM AUTHOR]

Studies were conducted to obtain a complex enzyme preparation that allows efficient hydrolysis of the main plant nonstarch polysaccharides (cellulose, xylans, and pectin). The goal of the studies was to optimize the composition of a fermentation medium for the submerged cultivation of the new mutant strain T. reesei Co-44, a highly active producer of endo-carbohydrases. A concentrate of low molecular soy components was chosen as the inducer of the key carbohydrase biosynthesis by the strain. This concentrate provided the maximum (more than eightfold) increase in polygalacturonase activity and an increased level of endoglucanase and xylanase biosynthesis. After the cultivation of T. reesei Co-44 under optimized conditions, a complex enzyme preparation, Xylorizin K4, was obtained, and its physicochemical properties were studied. The presence of endopolygalacturonase (GH28) T. reesei in Xylorizin K4 was confirmed via electrophoresis and MALDI⎯TOF mass spectrometry. The studies show the potential of Xylorizin K4 application for the production of soy-protein concentrates to eliminate the main soybean nonstarch polysaccharides. [ABSTRACT FROM AUTHOR]

Lignocellulosic biomass conversion using cellulases/polygalacturonases is a process that can be progressively influenced by several determinants involved in cellulose microfibril degradation. This article focuses on the kinetics and thermodynamics of thermal inactivation of recombinant Escherichia coli cellulases, cel12B, cel8C and a polygalacturonase, peh 28, derived from Pectobacterium carotovorum sub sp. carotovorum. Several consensus motifs conferring the enzymes' thermal stability in both cel12B and peh28 model structures have been detailed earlier, which were confirmed for the three enzymes through the current study of their thermal inactivation profiles over the 20–80°C range using the respective activities on carboxymethylcellulose and polygalacturonic acid. Kinetic constants and half-lives of thermal inactivation, inactivation energy, plus inactivation entropies, enthalpies and Gibbs free energies, revealed high stability, less conformational change and protein unfolding for cel12B and peh28 due to thermal denaturation compared to cel8C. The apparent thermal stability of peh28 and cel12B, along with their hydrolytic efficiency on a lignocellulosic biomass conversion as reported previously, makes these enzymes candidates for various industrial applications. Analysis of the Gibbs free energy values suggests that the thermal stabilities of cel12B and peh28 are entropy-controlled over the tested temperature range. [ABSTRACT FROM AUTHOR]

The effect of static and multi-pulsed high pressure processing (HPP) on the activity of hydrolyzing enzymes and the rheological properties of cloudy carrot juice during refrigerated storage (4 °C for 12 weeks) were investigated. The changes in the carotenoid profile, total polyphenolic content (TPC), antioxidant potential, and color were also studied. After HPP treatment, the activity of polygalacturonase (PG) and pectinmethylesterase (PME) decreased significantly. During the storage, the activity of PG increased by a maximum of 40% for 450 MPa, whereas PME activity decreased by a maximum of 76% for 300 MPa × 3 and 600 MPa. The apparent dynamic viscosity and turbidity changed after HPP treatment and storage. Seven carotenoids were identified in the untreated juice and their concentration increased significantly as increased pressure during the treatment. The carotenoids underwent significant degradation during the storage, which also correlated with changes in the a* and b* color parameters. The storage time also had a significant impact on the TPC and antioxidant capacity determined with DPPH and ABTS tests. [ABSTRACT FROM AUTHOR]

Apolygus lucorum (Miridae) is an omnivorous pest that occurs worldwide and is notorious for the serious damage it causes to various crops and substantial economic losses. Although some studies have examined the biological characteristics of the mirid bug, no reference genome is available in Miridae, limiting in‐depth studies of this pest. Here, we present a chromosome‐scale reference genome of A. lucorum, the first sequenced Miridae species. The assembled genome size was 1.02 Gb with a contig N50 of 785 kb. With Hi‐C scaffolding, 1,016 Mb contig sequences were clustered, ordered and assembled into 17 large scaffolds with scaffold N50 length 68 Mb, each corresponding to a natural chromosome. Numerous transposable elements occur in this genome and contribute to the large genome size. Expansions of genes associated with omnivorousness and mesophyll feeding such as those related to digestion, chemosensory perception, and detoxification were observed in A. lucorum, suggesting that gene expansion contributed to its strong environmental adaptability and severe harm to crops. We clarified that a salivary enzyme polygalacturonase is unique in mirid bugs and has significantly expanded in A. lucorum, which may contribute to leaf damage from this pest. The reference genome of A. lucorum not only facilitates biological studies of Hemiptera as well as an understanding of the damage mechanism of mesophyll feeding, but also provides a basis on which to develop efficient control technologies for mirid bugs. [ABSTRACT FROM AUTHOR]

To overcome the human and animal survivability risk, sustainable development is the only option on earth that can be achieved through the maximum use of renewable environmental resources. Recycling of waste paper is an emerging waste management approach to conserve natural resources. Herein, we studied enzyme-mediated process to recycle the xerographic paper by using the crude fungal extract from indigenously isolated fungi identified as Aspergillus assiutensis. The fungal enzyme cocktail has been characterized for the production of multiple enzymes namely cellulase, amylase, xylanase, pectinase, and protease. All these enzymes have pH optima in the acidic range and except cellulase and all the enzymes are stable from 10 to 80 C. In the zymogram analysis, pectinase, xylanase, amylase, and cellulase were detected at 68 kDa, ~ 54 kDa, 38 kDa, and 30 kDa, respectively. Also, the presence of protease was confirmed by the clear zone at 68, 31, and 16 kDa. A 26% decrease in the kappa number and reduction in Hex A of the pulp was observed on the treatment of the pulp with enzyme as compared to the control pulp without any treatment. The physical and chemical properties of the pulp were also improved by enzyme-mediated pulping as compared to the control The physiochemical parameter of the effluent like TDS was reduced (397 ppm) significantly in comparison to chemical deinking process and it was within the permissible limit. BOD and alkalinity were reduced when the enzymes and chemical dosage were used in combination. These results indicate that chemi-enzymatic deinking is most promising to reduce or remove the pollution parameters including ink and this approach can be used in the paper and pulp industry for sustainable development., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Rapeseed (Brassica napus L.), accounts for nearly 16% of vegetable oil, is the world's second produced oilseed. However, pod shattering has caused significant yield loses in rapeseed production, particularly during mechanical harvesting. The GH28 genes can promote pod shattering by changing the structure of the pod cell wall in Arabidopsis. However, the role of the GH28 gene family in rapeseed was largely unknown. Therefore, a genome-wide comprehensive analysis was conducted to classify the role of GH28 gene family on rapeseed pod shattering. A total of 37 BnaGH28 genes in the rapeseed genome were identified. These BnaGH28s can be divided into five groups (Group A-E), based on phylogenetic and synteny analysis. Protein property, gene structure, conserved motif, cis-acting element, and gene expression profile of BnaGH28 genes in the same group were similar. Specially, the expression level of genes in group A-D was gradually decreased, but increased in group E with the development of silique. Among eleven higher expressed genes in group E, two BnaGH28 genes (BnaA07T0199500ZS and BnaC06T0206500ZS) were significantly regulated by IAA or GA treatment. And the significant effects of BnaA07T0199500ZS variation on pod shattering resistance were also demonstrated in present study. These results could open a new window for insight into the role of BnaGH28 genes on pod shattering resistance in rapeseed., (© 2024. The Author(s).)