Polygalacturonase Research Articles

Pre-storage melatonin treatment maintains cell membrane integrity, reduces fruit browning and decay incidence in guava (Psidium guajava)

An experiments were conducted during 2021–22 at ICAR-Indian Agricultural Research Institute, New Delhi to study the impact of melatonin (MT) on key characteristics of guava (Psidium guajava L. cv. Barafkhana). Guava fruits were treated with different MT concentrations (200, 400, 600 and 800 μM) and stored at 10±1°C with 85–90% RH. The research revealed that treating with 600 μM MT notably decreased polyphenoloxidase activity by 57%, leading to delayed peel browning and also suppressed polygalacturonase (PG) activity by approximately 45% and pectine methylesterase activity by about 73%, resulting in higher firmness (5.33 N). Following a 20-days period of cold storage, significant reductions in electrolyte leakage, hydrogen peroxide accumulation and lipoxygenase activity were observed, thereby preserving cell membrane integrity. Additionally, MT stimulated the antioxidant defense system, boosted proline content accumulation, and enhanced phenylalanine ammonia-lyase activity. Together, these effects contributed to enhanced resistance against postharvest fungal decay (8.75%). In conclusion, MT at a concentration of 600 μM proves to be an effective postharvest treatment for maintaining texture, reducing fruit decay and extending the shelf-life of guava during cold storage.

Integrated transcriptomic, metabolomic, and functional analyses unravel the mechanism of bagging delaying fruit cracking of pomegranate (Punica granatum L.)

The economic impact of fruit cracking in pomegranate products is substantial. In this study, we present the inaugural comprehensive analysis of transcriptome and metabolome in the outermost pericarp of pomegranate fruit in bagging conditions. Our investigation revealed a notable upregulation of differentially expressed genes (DEGs) associated with the calcium signaling pathway (76.92%) and xyloglucan endotransglucosylase/hydrolase (XTH) genes (87.50%) in the fruit peel of non-cracking fruit under bagging. Metabolomic analysis revealed that multiple phenolics, flavonoids, and tannins were identified in pomegranate. Among these, calmodulin-like 23 (PgCML23) exhibited a significant correlation with triterpenoids and demonstrated a marked upregulation under bagging treatment. The transgenic tomatoes overexpressing PgCML23 exhibited significantly higher cellulose content and xyloglucan endotransglucosylase (XET) enzyme activity in the pericarp at the red ripening stage compared to the wild type. Conversely, water-soluble pectin content, polygalacturonase (PG), and β-galactosidase (β-GAL) enzyme activities were significantly lower in the transgenic tomatoes. Importantly, the heterologous expression of PgCML23 led to a substantial reduction in the fruit cracking rate in tomatoes. Our findings highlight the reduction of fruit cracking in bagging conditions through the manipulation of PgCML23 expression.

Zig, Zag, and ’Zyme: leveraging structural biology to engineer disease resistance

AbstractDynamic host–pathogen interactions determine whether disease will occur. Pathogen effector proteins are central players in such disease development. On one hand, they improve susceptibility by manipulating host targets; on the other hand, they can trigger immunity after recognition by host immune receptors. A major research direction in the study of molecular plant pathology is to understand effector-host interactions, which has informed the development and breeding of crops with enhanced disease resistance. Recent breakthroughs on experiment- and artificial intelligence-based structure analyses significantly accelerate the development of this research area. Importantly, the detailed molecular insight of effector–host interactions enables precise engineering to mitigate disease. Here, we highlight a recent study by Xiao et al., who describe the structure of an effector-receptor complex that consists of a fungal effector, with polygalacturonase (PG) activity, and a plant-derived polygalacturonase-inhibiting protein (PGIP). PGs weaken the plant cell wall and produce immune-suppressive oligogalacturonides (OGs) as a virulence mechanism; however, PGIPs directly bind to PGs and alter their enzymatic activity. When in a complex with PGIPs, PGs produce OG polymers with longer chains that can trigger immunity. Xiao et al. demonstrate that a PGIP creates a new active site tunnel, together with a PG, which favors the production of long-chain OGs. In this way, the PGIP essentially acts as both a PG receptor and enzymatic manipulator, converting virulence to defense activation. Taking a step forward, the authors used the PG-PGIP complex structure as a guide to generate PGIP variants with enhanced long-chain OG production, likely enabling further improved disease resistance. This study discovered a novel mechanism by which a plant receptor plays a dual role to activate immunity. It also demonstrates how fundamental knowledge, obtained through structural analyses, can be employed to guide the design of proteins with desired functions in agriculture.

Assessing the Effect of Cold Plasma on the Softening of Postharvest Blueberries through Reactive Oxygen Species Metabolism Using Transcriptomic Analysis.

The postharvest softening and corresponding quality deterioration of blueberry fruits are crucial factors that hinder long-distance sales and long-term storage. Cold plasma (CP) is an effective technology to solve this, but the specific mechanism of delaying fruit softening remains to be revealed. Here, this study found that CP significantly improved blueberry hardness. Physiological analysis showed that CP regulated the dynamic balance of reactive oxygen species (ROS) to maintain hardness by increasing antioxidant content and antioxidant enzyme activity, resulting in a 12.1% decrease in the H2O2 content. Transcriptome analysis revealed that CP inhibited the expression of cell wall degradation-related genes such as the pectin hydrolase gene and cellulase gene, but up-regulated the genes of the ROS-scavenging system. In addition, the resistance genes in the MAPK signaling pathway were also activated by CP in response to fruit ripening and softening and exhibited positive response characteristics. These results indicate that CP can effectively regulate the physiological characteristics of blueberries at a genetic level and delay the softening process, which is of great significance to the storage of blueberries.

Structural and biochemical characterization of SmoPG1, an exo-polygalacturonase from Selaginella moellendorffii

Polygalacturonases (PGs) can modulate chemistry and mechanical properties of the plant cell wall through the degradation of pectins, one of its major constituents. PGs are largely used in food, beverage, textile, and paper industries to increase processes' performances. To improve the use of PGs, knowledge of their biochemical, structural and functional features is of prime importance. Our study aims at characterizing SmoPG1, a polygalacturonase from Selaginella moellendorffii, that belongs to the lycophytes. Transcription data showed that SmoPG1 was mainly expressed in S. moellendorffii shoots while phylogenetic analyses suggested that SmoPG1 is an exo-PG, which was confirmed by the biochemical characterization following its expression in heterologous system. Indeed, LC-MS/MS oligoprofiling using various pectic substrates identified galacturonic acid (GalA) as the main hydrolysis product. We found that SmoPG1 was most active on polygalacturonic acid (PGA) at pH 5, and that its activity could be modulated by different cations (Ca2+, Cu2+, Fe2+, Mg2+, Mn2+, Na2+, Zn2+). In addition, SmoPG1 was inhibited by green tea catechins, including (−)-epigallocatechin-3-gallate (EGCG). Docking analyses and MD simulations showed in detail amino acids responsible for the SmoPG1-EGCG interaction. Considering its expression yield and activity, SmoPG1 appears as a prime candidate for the industrial production of GalA.

The role of water distribution, cell wall polysaccharides, and microstructure on radish (Raphanus sativus L.) textural properties during dry-salting process

Radish (Raphanus sativus L.) undergoes texture changes in their phy-chemical properties during the long-term dry-salting process. In our study, we found that during the 60-day salting period, the hardness and crispness of radish decreased significantly. In further investigation, we observed that the collaborative action of pectin methylesterase (PME) and polygalacturonase (PG) significantly decreased the total pectin, alkali-soluble pectin (ASP), and chelator-soluble pectin (CSP) content, while increasing the water-soluble pectin (WSP) content. Furthermore, the elevated activities of cellulase and hemicellulase directly led to the notable fragmentation of cellulose and hemicellulose. The above reactions jointly induced the depolymerization and degradation of cell wall polysaccharides, resulting in an enlargement of intercellular spaces and shrinkage of the cell wall, which ultimately led to a reduction in the hardness and crispness of the salted radish. This study provided key insights and guidance for better maintaining textural properties during the dry-salting process of radish.

Polygalacturonase-inhibiting proteins as an exogenously applied natural solution for prevention of postharvest fungal infections

Polygalacturonase inhibiting proteins (PGIPs) are plant proteins involved in the inhibition of polygalacturonases (PGs), cell-wall degrading enzymes often secreted by phytopathogenic fungi. Previously, we confirmed that PGIP2 from Phaseolus vulgaris (PvPGIP2) can inhibit the growth of Aspergillus niger and Botrytis cinerea on agar plate. In this study, we further validated the feasibility of using PGIP as an environmental and ecological friendly agent to prevent fungal infection post-harvest. We found that application of either purified PGIP (full length PvPGIP2 or truncated tPvPGIP2_5–8), or PGIP-secreting Saccharomyces cerevisiae strains can effectively inhibit fungal growth and necrotic lesions on tobacco leaf. We also examined the effective amount and thermostability of PGIP when applied on plants. A concentration of 0.75 mg/mL or higher can significantly reduce the area of B. cinerea lesions. The activity of full-length PvPGIPs is not affected after incubation at various temperatures ranging from −20 to 42 °C for 24 h, while truncated tPvPGIP2_5–8 lost some efficacy after incubation at 42 °C. Furthermore, we have also examined the efficacy of PGIP on tomato fruit. When the purified PvPGIP2 proteins were applied to tomato fruit inoculated with B. cinerea at a concentration of roughly 1.0 mg/mL, disease incidence and area of disease had reduced by more than half compared to the controls without PGIP treatment. This study explores the potential of PGIPs as exogenously applied, eco-friendly fungal control agents on fruit and vegetables post-harvest.

Enhancing postharvest quality and extending storage life of Booth 7 avocado (Persea americana Mill.) fruit through sodium nitroprusside (SNP) application during low-temperature storage

Postharvest quality plays a crucial role in marketability, consumer acceptability, and shelf life of avocados. This study investigates the efficacy of nitric oxide (NO) on postharvest physiology and quality of Booth 7 avocados treated with different concentrations of sodium nitroprusside (SNP) - a nitric oxide-releasing compound. Booth 7 avocados were immersed in SNP solutions (0.5 mM, 1.0 mM, and 1.5 mM), while the control fruit was immersed in distilled water for 15 min. After treatment, the fruit was stored at a temperature (T) of 8 ± 1 °C and relative humidity (RH) of 90 ± 5% for 35 days, during which the control fruit exhibited complete deterioration. The results revealed that Booth 7 avocados treated with 1.5 mM SNP concentration exhibited delayed quality changes during storage, reduced ethylene production and respiration rate, reduced alterations in soluble solids and acid content of the fruit flesh, as well as delayed changes in flesh and peel color. Additionally, the activity of total phenolic compounds (TPC), polygalacturonase (PG), and polyphenol oxidase (PPO) enzymes increased significantly, while the activity of the pectin methyl esterase (PME) enzyme was reduced. In conclusion, SNP treatment improved the quality and can be utilized as a potential postharvest preservative for Booth 7 avocados. For producers and distributors, the use of SNP in avocado postharvest management offers the potential to extend shelf life without compromising fruit quality.

Effect of ozone treatment on the decay and cell wall metabolism during the postharvest storage of cantaloupe

Cantaloupe is a popular summer fruit with immense market potential in China. However, the cantaloupe fruits generally soften rapidly after harvest, which dramatically reduces their economic value. The ozone treatment has been found to be effective in delaying the softening of cantaloupe fruit. The results indicated that ozone treatment significantly inhibited the mycelial growth of Fusarium hypha. The ozone treatment was able to delay the decline of total soluble solids, lower the respiration rate, and maintain the fruit's firmness without damaging fruit quality. The study also indicated that the activity and gene expression of cell wall degrading enzymes such as polygalacturonase (PG), pectin methylesterase (PME), β-galactosidase (β-gal), cellulose (Cx), and α-l-arabinofuranosidase (α-l-Af), were inhibited under ozone treatment, which also suppressed the degradation of cell wall components associated with fruit softening (protopectin, soluble pectin, cellulose, and hemicellulose). These changes may contribute to the maintenance of cell wall components, thereby delaying the fruit softening. In conclusion, these results suggested that ozone can improve the fruit quality of cantaloupe by suppressing postharvest fungal diseases and delaying fruit softening, which provides a theoretical basis for further research on cell wall metabolism during cantaloupe storage.

Genome-wide analysis of the PG gene family in Penicillium expansum: Expression during the infection stage in pear fruits (Pyrus bretschneideri)

Penicillium expansum is a necrotrophic plant pathogen that has a broad range of fruit hosts and is responsible for blue mold rot. This rot has a significant impact on the fruit industry, causing economic losses during storage, transport, and sale. Polygalacturonase (PGs) enzymes are essential for pathogenic fungi to break down pectin, as they hydrolyze the polygalacturonic acid chain along the oxygen bridge. This enzyme has been identified in decayed tissue and is linked to multiple soft rot diseases. This study encompasses a thorough examination of the PGs gene family within the genome of P. expansum, utilizing a genome-wide analysis approach. As a result, a total of seven PG genes were successfully found. These genes were phylogenetically divided into four distinct clades. The gene structural characteristics of each group exhibited a fundamental level of conservation. Furthermore, the gene architectures and motif compositions exhibited robust evidence in favor of the credibility of the phylogenetic relationship. Motif analysis reveals that most of the motifs predicted had Glycosyl hydrolases family 28 conserved domains (PF00295). Analysis of RNA-seq data and the PG genes identified by RT-qPCR were mostly upregulated. Hence, comprehending the characteristics of PePGs holds significant scientific importance and will offer comprehensive insights into the PG superfamily in P. expansum and will make a valuable contribution to the ongoing validation of functional genes.

Chromosome-level genome assemblies of Musa ornata and M. velutina provide insights into pericarp dehiscence and anthocyanin biosynthesis in banana

Abstract Musa ornata and M. velutina are members of the Musaceae family and are indigenous to the South and Southeast Asia. They are very popular in the horticultural market, but the lack of genomic sequencing data and genetic studies has hampered efforts to improve their ornamental value. In this study, we generated the first chromosome-level genome assemblies for both species by utilizing Oxford Nanopore long reads and Hi-C reads. The genomes of M. ornata and M. velutina were assembled into 11 pseudochromosomes with genome sizes of 427.85 Mb and 478.10 Mb, respectively. Repetitive sequences comprised 46.70% and 50.91% of the total genomes for M. ornata and M. velutina, respectively. Differentially expressed gene (DEG) and Gene Ontology (GO) enrichment analyses indicated that upregulated genes in the mature pericarps of M. velutina were mainly associated with the saccharide metabolic processes, particularly at the cell wall and extracellular region. Furthermore, we identified polygalacturonase (PG) genes that exhibited higher expression level in mature pericarps of M. velutina compared to other tissues, potentially being accountable for pericarp dehiscence. This study also identified genes associated with anthocyanin biosynthesis pathway. Taken together, the chromosomal-level genome assemblies of M. ornata and M. velutina provide valuable insights into the mechanism of pericarp dehiscence and anthocyanin biosynthesis in banana, which will significantly contribute to future genetic and molecular breeding efforts.

Effects of transport vibration on storage quality and expression of genes related to cell wall metabolism of winter jujube (Zizyphus jujuba Mill. cv. Dalidongzao)

Winter jujube (Zizyphus jujuba Mill. cv. Dalidongzao) is susceptible to machinery damage due to its high moisture content. The present study investigates the impact of varying levels of vibration acceleration on the softening and quality deterioration of winter jujubes through utilization of a simulated transport platform. The results demonstrated that, in comparison to the control group, winter jujubes treated with vibration exhibited a higher susceptibility to decay and weight loss. Additionally, they displayed an elevated respiration intensity and experienced a significant depletion of nutrients. The vibration promoted an increase in enzyme activity of polygalacturonase (PG), pectin methylesterase (PME) and cellulase (Cx), upregulated gene expression, and induced a reduction in pectin, cellulose and hemicellulose content, ultimately resulting in the softening of winter jujube. The hardness of winter jujube decreased by 34.87%, 37.80% and 44.92% in the shelf life under vibration accelerations of 0.25g, 0.5g and 0.75g, respectively, whereas it only decreased by 28.60% in the control group. In addition, the damage caused by vibration was also observed in the microstructure of peel and pulp. The findings demonstrate that the vibrational impact significantly influenced the quality of winter jujube, resulting in a reduced shelf life and diminished commodity value.

Purification, biochemical characterization, and biotechnological applications of a multifunctional enzyme from the Thermoascus aurantiacus PI3S3 strain

The filamentous Thermoascus aurantiacus fungus characterized by its thermophilic nature, is recognized as an exceptional producer of various enzymes with biotechnological applications. This study aimed to explore biotechnological applications using polygalacturonase (PG) derived from the Thermoascus aurantiacus PI3S3 strain. PG production was achieved through submerged fermentation and subsequent purification via ion-exchange chromatography and gel filtration methods. The crude extract exhibited a diverse spectrum of enzymatic activities including amylase, cellulase, invertase, pectinase, and xylanase. Notably, it demonstrated the ability to hydrolyze sugarcane bagasse biomass, corn residue, and animal feed. The purified PG had a molecular mass of 36 kDa, with optimal activity observed at pH 4.5 and 70 °C. The activation energy (Ea) was calculated as 0.513 kJ mol−1, highlighting activation in the presence of Ca2+. Additionally, it displayed apparent Km, Vmax, and Kcat values of at 0.19 mg mL−1, 273.10 U mL−1, and 168.52 s−1, respectively, for hydrolyzing polygalacturonic acid. This multifunctional PG exhibited activities such as denim biopolishing, apple juice clarification, and demonstrated both endo- and exo-polygalacturonase activities. Furthermore, it displayed versatility by hydrolyzing polygalacturonic acid, carboxymethylcellulose, and xylan. The T. aurantiacus PI3S3 multifunctional polygalacturonase showed heightened activity under acidic pH, elevated temperatures, and in the presence of calcium. Its multifunctional nature distinguished it from other PGs, significantly expanding its potential for diverse biotechnological applications.

β-Aminobutyric Acid Effectively Postpones Senescence of Strawberry Fruit by Regulating Metabolism of NO, H2S, Ascorbic Acid, and ABA

Current researchis focused on the influence of β-aminobutyric acid (BABA) on the metabolism of nitric oxide (NO), hydrogen sulfide (H2S), ascorbic acid, and abscisic acid (ABA) in strawberry fruit. The increases in ion leakage and malondialdehyde (MDA) concentration in strawberry fruit and the degradation of chlorophyll in the sepals of the fruit were markedly inhibited by BABA at 20 mM. BABA-immersed fruit exhibited lower activities and expressions of polygalacturonase (PG), pectinmethylesterase (PME), and ethylene biosynthetic enzymes compared to the control. Furthermore, BABA immersion evidently upgraded the metabolic levels of NO and H2S, including the enzymatic activities and intermediary contents of metabolites, which collectively enhanced the levels of endogenous NO and H2S contents in strawberry fruit. The high enzymatic activities and gene expressions of the AsA biosynthesis pathway jointly maintained AsA accumulation in the BABA-treated sample. The application of BABA led to a decrease in ABA concentration, which was associated with reduced activities and gene expression levels of key enzymes participating in ABA metabolism. Our experimental observations showed that immersion with BABA may be a highly promising means to delay senescence and reduce natural decay in strawberry fruit, and the alleviation in senescence using BABA may be attributed to the modulation of NO, H2S, AsA, and ABA metabolism.

Enhancing peach quality and extending storability by regulating ethylene metabolism and enzymes using 1-(3-phenyl-propyl) cyclopropene and salicylic acid

ABSTRACT To assess the influence of 1-(3-phenyl-propyl) cyclopropene (1-PPCP) and salicylic acid (SA) on the storability of peach (cv. ‘Early Swelling’), we applied the following treatments; 5 μL L−1 1-PPCP for 24 h, 2 mmol L−1 SA for 5 min, and a combination of both treatments, concurrently, a control group. The fruit samples were stored at 6 ± 1°C with 90–95% RH for 28 d, followed by 3 d at 20°C to simulate market shelf life. The objective was to maintain fruit quality and enhance fruit storability. 1-PPCP+SA significantly reduced decay, weight loss, and respiration rate, while also contributing to the maintenance of fruit colouration and SSC. The treatments also led to a decrease in browning incidence, malondialdehyde levels, and electrolyte leakage. Additionally, they effectively slowed down the activity of polyphenol oxidase (PPO). Furthermore, all treatments led to a reduction in ethylene production and the activity of key enzymes involved in ethylene biosynthesis, such as ACC-synthase and ACC-oxidase, when compared to the control group. Additionally, these treatments regulated related pectin-degrading enzymes such as pectin methylesterase (PME), β-galactosidase (β-Gal), and polygalacturonase (PG). Therefore, the utilisation of 1-PPCP and SA is suggested as post-harvest treatments to enhance the storability of peach while preserving overall quality.

Influence of myoinositol on post-ripening and softening of Prunus salicina ‘Wushan plum’

To investigate the impact of myoinositol (MI) immersion treatment on the storage characteristics of Prunus salicina ‘Wushan Plum’, we assessed myoinositol content, ascorbic acid content, weight loss, decay rate, alteration in color, titratable acidity (TA), soluble solids (TSS), firmness, cell wall metabolism-related compounds, enzyme activities, and levels of gene expression throughout a 15-day storage period at 25 °C. The results revealed that MI treatment could increase myoinositol and ascorbic acid contents of fruit during the pre-storage period, effectively delay the color transformation and decay progression of P. salicina ‘Wushan Plum’ while maintaining elevated levels of TA and TSS. Furthermore, it suppressed the increase in weight loss and the decline in firmness. Notably, the delay in softening was more pronounced in the group treated with 100 mg L−1 MI compared to other groups. MI treatment regulated the expression levels of various genes associated with cell wall metabolism, which resulted in reduced activities of polygalacturonase (PG), pectate lyase (PL), pectin methylesterase (PME), cellulase (Cx), and β-glucosidase (β-Glu), and increased activities of phenylalanine ammonia-lyase (PAL) and cinnamyl alcohol dehydrogenase (CAD). Furthermore, MI treatment maintained higher levels of covalently bound pectin (CSP), cellulose, and lignin, while decreasing the levels of water-soluble pectin (WSP) in the fruit. As a result, MI treatment could delay the depolymerization of cell wall polysaccharides and further delay the quality deterioration of P. salicina ‘Wushan Plum’ fruits under ambient storage environment and prolong the storage period.

Overexpression of the Rubus idaeus Polygalacturonases Gene RiPG2 Accelerates Fruit Softening in Solanum lycopersicum

The high susceptibility of raspberries to softening restricts the development of the raspberry industry. The primary causes of fruit softening are the breakdown of components linked to the cell wall and the destruction of the cell wall structure itself. Polygalacturonase (PG), a key enzyme that catalyzes pectin degradation, plays a critical role in fruit softening. However, there are currently limited studies on the mechanism of PG genes in raspberry fruit softening. In this study, a PG gene, RiPG2, was isolated from raspberry (Rubus idaeus L.). ‘Polka’ fruits and tomato plants overexpressing RiPG2 were obtained by Agrobacterium tumefaciens-mediated leaf disc transformation to elucidate the role of RiPG2 in fruit softening. The total length of the RiPG2 gene is 1185 bp, and the gene encodes a total of 394 amino acids. The GFP fusion protein was expressed at the chloroplast under laser confocal microscopy, indicating that the RiPG2 protein is localized to the chloroplasts. Phenotypic analysis revealed that the fruit firmness of three strains was considerably less than that of controls, but PG enzyme activity was increased. Overexpression of RiPG2 altered the content of cell wall components, with an increase in water-soluble pectin (WSP) and ion-bound pectin (ISP) but a decrease in protopectin, cellulose, hemicellulose, and covalently bound pectin (CSP). In addition, RiPG2 positively regulated the expression of cell wall metabolism-related genes such as SlEXP1, SlTBG4, SlXTH5, and SlPL. These results suggest that the RiPG2 gene regulates the structure and composition of the cell wall and acts synergistically with other cell wall metabolism-related genes to promote fruit softening. This study provides a new candidate gene for molecular breeding to improve raspberry firmness.

Exploring the Effects of Different 1-MCP Concentration Treatment on Chilling Injury of Postharvest Peach Fruit

Peach (Prunus persica (L.) Batsch) fruit are susceptible to chilling injury that is often manifested as browning of the internal flesh. As the ethylene antagonist, 1-methylcyclopropene (1-MCP) is an important contributor to resist chilling stress during peach (Prunus persica (L.) Batsch) storage at low temperatures, but the molecular mechanism of it is still elusive. The study examined in detail the effects of two concentrations (1 and 2 μL·L−1) of 1-MCP on alleviating chilling injury (CI) of postharvest peach fruit stored at 4 ± 0.5°C. The results showed that although all treatments relieved CI, treatment with 1 μL·L−1 more effectively alleviated CI symptoms of postharvest peach fruit than 2 μL·L−1. The internal browning (IB) and weight loss were significantly inhibited by 1 μL·L−1 1-MCP. Lower concentration of 1-MCP maintained normal softening by decreasing the gene expression of expansin (Exp) 1,3, polygalacturonase (PG) 3, and pectate lyase (PLY) 1, 2, 3 and increased the content of soluble sugar during the whole storage period. Meanwhile, the activities of polygalacturonase, pectinmethylesterase (PME), and endo-1,4-β-glucanase (EGase) were reduced by lower concentration of 1-MCP. Our results demonstrate that 1-MCP inhibited CI by suppressing the degradation of cell wall. This study provides a theoretical basis for revealing that 1-MCP alleviates chilling injury in peach fruit.

Thermoalkalophilic polygalacturonase from a novel Glutamicibacter sp.: Bioprospecting, strain improvement, statistical optimization and applications

The current research discusses a multidimensional bioprocess development, that includes bioprospecting, strain improvement, media optimisation, and applications of the extracted enzyme. A potent alkalophilic polygalacturonase (PG) producing bacterial strain was isolated and identified as a novel Glutamicibacter sp. Furthermore, strain improvement by UV and chemical mutagenesis not only improved the enzyme (PGmut) production but also enhanced its temperature optima from 37 °C to 50 °C. The use of solid substrate fermentation, followed bystatistical optimisation through PB and RSM, substantially increasedPGmut production. A 10-fold increase in enzyme production (632 U/gm) was observed when sugarcane bagasse with a pH of 10.5, 66.8 % moisture, and an inoculum size of 10.15 % was used. The model’s accuracy was supported by p-value (p < 0.0001), and an R2 of 0.9940. A pilot-scale experiment, demonstrated ≈ 62,229 U/100 gm PG activity. Additionally, the enzyme’s efficacy in demucilization of coffee beans, and bioscouring of jute fibre indicated that it is a valuable biocatalyst.

The Outlook of Tomatoes with extended Shelf Life in Nigeria and the Ensuing Safety Measures and Regulated Introduction by Nigerian Regulatory Authorities

Tomato (Solanum lycopersicum) is widely consumed worldwide. The primary chance to influence tomatoes' edibility and market value lies in regulating the synthesis and function of the plant hormone ethylene responsible for ripening. The usage of harmless substances on tomato surfaces, a reduction in storage temperature, the implementation of modified atmosphere packaging, or a combination of these approaches have been associated with increasing tomatoes’ shelf life. As crop plants containing a genetically modified trait through molecular techniques continue their transition from the laboratory to the field, the National Biotechnology Development Agency (NABDA) has been reported to be developing genetically modified (GM) tomatoes by deactivating polygalacturonase (PG) gene that is responsible for polygalacturonase which is the enzyme that aids fruit softening and subsequently increases the shelf life of the tomatoes to be released in the Nigerian market. This article looks at tomatoes (S. lycopersicum) and the methods used in increasing their shelf life with more focus on the genetically modified tomatoes and the needed regulations by the Nigerian regulatory bodies before its commercialization in the country. Environmental and health hazards that require careful consideration in the course of embarking on the genetical modification and introduction of the hybrid tomatoes into the Nigeria markets encompass potential biodiversity loss, adverse impacts on natural food chains, and the potential rise of more virulent pathogen populations. Nevertheless, it is crucial to emphasize that the biotechnological processes and products must be accompanied by effective regulations to mitigate these concerns, National Biosafety Management Agency is believed to be engaged with these needs.