Metabolic novelty originating from horizontal gene transfer is essential for leaf beetle survival.

Horizontal gene transfer (HGT) provides an evolutionary shortcut for recipient organisms to gain novel functions. Although reports of HGT in higher eukaryotes are rapidly accumulating, in most cases the evolutionary trajectory, metabolic integration, and ecological relevance of acquired genes remain unclear. Plant cell wall degradation by HGT-derived enzymes is widespread in herbivorous insect lineages. Pectin is an abundant polysaccharide in the walls of growing parts of plants. We investigated the significance of horizontally acquired pectin-digesting polygalacturonases (PGs) of the leaf beetle Phaedon cochleariae. Using a CRISPR/Cas9-guided gene knockout approach, we generated a triple knockout and a quadruple PG-null mutant in order to investigate the enzymatic, biological, and ecological effects. We found that pectin-digestion 1) is exclusively linked to the horizontally acquired PGs from fungi, 2) became fixed in the host genome by gene duplication leading to functional redundancy, 3) compensates for nutrient-poor diet by making the nutritious cell contents more accessible, and 4) facilitates the beetles development and survival. Our analysis highlights the selective advantage PGs provide to herbivorous insects and demonstrate the impact of HGT on the evolutionary success of leaf-feeding beetles, major contributors to species diversity.

Genome-wide identification of GH28 family and insight into its contributions to pod shattering resistance in Brassica napus L.

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.

Prophylactic phage biocontrol prevents Burkholderia gladioli infection in a quantitative ex planta model of bacterial virulence.

Agricultural crop yield losses and food destruction due to infections by phytopathogenic bacteria such as Burkholderia gladioli, which causes devastating diseases in onion, mushroom, corn, and rice crops, pose major threats to worldwide food security and cause enormous damage to the global economy. Biocontrol using bacteriophages has emerged as a promising strategy against a number of phytopathogenic species but has never been attempted against B. gladioli due to a lack of quantitative infection models and a scarcity of phages targeting this specific pathogen. In this study, we present a novel, procedurally straightforward, and highly generalizable fully quantitative ex planta maceration model and an accompanying quantitative metric, the ex planta maceration index (xPMI). In utilizing this model to test the ex planta virulence of a panel of 12 strains of B. gladioli in Allium cepa and Agaricus bisporus, we uncover substantial temperature-, host-, and strain-dependent diversity in the virulence of this fascinating pathogenic species. Crucially, we demonstrate that Burkholderia phages KS12 and AH2, respectively, prevent and reduce infection-associated onion tissue destruction, measured through significant (P < 0.0001) reductions in xPMI, by phytopathogenic strains of B. gladioli, thereby demonstrating the potential of agricultural phage biocontrol targeting this problematic microorganism.IMPORTANCEAgricultural crop destruction is increasing due to infections caused by bacteria such as Burkholderia gladioli, which causes plant tissue diseases in onion, mushroom, corn, and rice crops. These bacteria pose a major threat to worldwide food production, which, in turn, damages the global economy. One potential solution being investigated to prevent bacterial infections of plants is "biocontrol" using bacteriophages (or phages), which are bacterial viruses that readily infect and destroy bacterial cells. In this article, we demonstrate that Burkholderia phages KS12 and AH2 prevent or reduce infection-associated plant tissue destruction caused by strains of B. gladioli, thereby demonstrating the inherent potential of agricultural phage biocontrol.

Transformation of agricultural wastes into functional oligosaccharides using enzymes and emerging technologies.

INTRODUCTION: Pectin-oligosaccharides (POS) serve diverse purposes as a food ingredient, antimicrobial and biostimulant in plants, and their functionality is linked to the degree of esterification. Grape and broccoli wastes emerge as environmentally friendly alternatives to obtaining pectin, serving as a sustainable source to producing POS. For example, microwaves have proven to be an effective and sustainable method to extract polysaccharides from plant matrices. OBJECTIVE: This work aims to use grape and broccoli wastes as alternative sources for obtaining pectin by microwave-assisted extraction and biotransformation into POS, which possess biological properties. MATERIAL AND METHODS: The extraction conditions were identified at a power of 400 W, 300 s for the extraction of pectin from grape pomace and broccoli waste. Biotransformation of pectins into POS, using commercial enzyme preparations (Viscozyme L and Pectinase). Characterisation was carried out by Fourier-transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. RESULTS: Physicochemical analysis indicated grape pomace and broccoli waste pectins had galacturonic acid content of 63.81 ± 1.67 and 40.83 ± 2.85 mg 100 mg-1, low degree of esterification of 34.89% and 16.22%, respectively. Biotransformation of pectins into POS resulted in a 20% hydrolysis rate. The main enzymatic activity was polygalacturonase for the degradation of the main structure of the pectin. CONCLUSION: Production of POS from agro-industrial wastes by emerging technologies, such as the combined use of microwave-assisted extraction and enzymatic processes, represents an alternative method for the generation of bioactive compounds with distinctive properties suitable for different applications of interest.

Genome-wide identification and expression analysis of the polygalacturonase gene family in sweetpotato.

BACKGROUND: Polygalacturonase (PG), a crucial enzyme involved in pectin degradation, is associated with various plants' developmental and physiological processes such as seed germination, fruit ripening, fruit softening and plant organ abscission. However, the members of PG gene family in sweetpotato (Ipomoea batatas) have not been extensively identified. RESULTS: In this study, there were 103 PG genes identified in sweetpotato genome, which were phylogenetically clustered into divergent six clades. The gene structure characteristics of each clade were basically conserved. Subsequently, we renamed these PGs according to their locations of the chromosomes. The investigation of collinearity between the PGs in sweetpotato and other four species, contained Arabidopsis thaliana, Solanum lycopersicum, Malus domestica and Ziziphus jujuba, revealed important clues about the potential evolution of the PG family in sweetpotato. Gene duplication analysis showed that IbPGs with collinearity relationships were all derived from segmental duplications, and these genes were under purifying selection. In addition, each promoter region of IbPG proteins contained cis-acting elements related to plant growth and development processes, environmental stress responses and hormone responses. Furthermore, the 103 IbPGs were differentially expressed in various tissues (leaf, stem, proximal end, distal end, root body, root stalk, initiative storage root and fibrous root) and under different abiotic stresses (salt, drought, cold, SA, MeJa and ABA treatment). IbPG038 and IbPG039 were down-regulated with salt, SA and MeJa treatment. According to the further investigation, we found that IbPG006, IbPG034 and IbPG099 had different patterns under the drought and salt stress in fibrous root of sweetpotato, which provided insights into functional differences among these genes. CONCLUSION: A total of 103 IbPGs were identified and classified into six clades from sweetpotato genome. The results of RNA-Seq and qRT-PCR suggested that IbPG006, IbPG034 and IbPG099 might play a significant role in tissue specificity as well as drought and salt stress responses, which showed valuable information for further functional characterization and application of the IbPGs.

Polygalacturonase gene family analysis identifies FcPG12 as a key player in fig (Ficus carica L.) fruit softening.

BACKGROUND: The fig (Ficus carica L.) tree has high economic value. However, its fruit have a short shelf life due to rapid softening. Polygalacturonases (PGs) are essential hydrolases, responsible for the pectin degradation that plays a key role in fruit softening. However, fig PG genes and their regulators have not yet been characterized. RESULTS: In this study, 43 FcPGs were identified in the fig genome. They were non-uniformly distributed on 13 chromosomes, and tandem repeat PG gene clusters were found on chromosomes 4 and 5. Ka/Ks calculation and collinear analysis indicated negative selection as the main driver of FcPG family expansion. Fourteen FcPGs were found expressed in fig fruit with FPKM values > 10, of which seven were positively correlated, and three, negatively correlated with fruit softening. Eleven FcPGs were upregulated and two downregulated in response to ethephon treatment. FcPG12, a member of the tandem repeat cluster on chromosome 4, was selected for further analyses due to its sharp increment in transcript abundance during fruit softening and its response to ethephon treatment. Transient overexpression of FcPG12 led to decreased fig fruit firmness and increased PG enzyme activity in the tissue. Two ethylene response factor (ERF)-binding GCC-box sites were found on the FcPG12 promoter. Yeast one-hybrid and dual luciferase assays showed that FcERF5 binds directly to the FcPG12 promoter and upregulates its expression. Transient overexpression of FcERF5 upregulated FcPG12 expression, thereby increasing PG activity and fruit softening. CONCLUSIONS: Our study identified FcPG12 as a key PG gene in fig fruit softening, and its direct positive regulation by FcERF5. The results provide new information on the molecular regulation of fig fruit softening.

Enhancement of novel Endo-polygalacturonase expression in Rhodotorula mucilaginosa PY18: insights from mutagenesis and molecular docking.

Pectinase is a particular type of enzyme that can break down pectin compounds and is extensively utilised in the agricultural field. In this study, twenty yeast isolates were isolated and assayed for pectinase activity. Molecular identification by PCR amplification and sequencing of internal transcribed spacer (ITS) regions of isolate no. 18 had the highest pectinase activity of 46.35 U/mg, was identified as Rhodotorula mucilaginosa PY18, and was submitted under accession no. (OM275426) in NCBI. Rhodotorula mucilaginosa PY18 was further enhanced through sequential mutagenesis, resulting in a mutant designated as Rhodotorula mucilaginosa E54 with a specific activity of 114.2 U/mg. Using Response Surface Methodology (RSM), the best culture conditions for the pectinase-producing yeast mutant Rhodotorula mucilaginosa E54 were pH 5, 72-h incubation, 2.5% xylose, and 2.5% malt extract, with a pectinase-specific activity of 156.55 U/mg. Then, the obtained sequences of the endo-polygalacturonase PGI gene from Rhodotorula mucilaginosa PY18 and mutant Rhodotorula mucilaginosa E54 were isolated for the first time, sequenced, and submitted to NCBI accession numbers OQ283005 and OQ283006, respectively. The modelled 3D structure of the endo-PGI enzyme (485 residues) was validated using Ramachandran's plot, which showed 87.71, 85.56, and 91.57% in the most favourable region for template Rhodotorula mucilaginosa KR, strain Rhodotorula mucilaginosa PY18, and mutant Rhodotorula mucilaginosa E54, respectively. In molecular docking studies, the results of template Rhodotorula mucilaginosa KR endo-PG1 showed an interaction with an affinity score of - 6.0, - 5.9, and - 5.6 kcal/mol for active sites 1, 2, and 3, respectively. Rhodotorula mucilaginosa PY18 endo-PG1 showed an interaction affinity with a score of - 5.8, - 6.0, and - 5.0 kcal/mol for active sites 1, 2, and 3, respectively. Mutant Rhodotorula mucilaginosa E54 endo-PG1 showed an interaction affinity of - 5.6, - 5.5, - 5.5 and - 5.4 kcal/mol for active sites 1, 2, and 3, respectively. The endo-PGI genes of both the yeast strain Rhodotorula mucilaginosa PY18 and mutant Rhodotorula mucilaginosa E54 were successfully cloned and expressed in E. coli DH5α, showing significantly higher endo-PG1 activity, which recorded 94.57 and 153.10 U/mg for recombinant Rhodotorula mucilaginosa pGEM-PGI-PY18 and recombinant mutant Rhotorula pGEM-PGI-E54, respectively.

Pectin decomposition at the early stage of brown-rot decay by Fomitopsis palustris.

The sapwood of Japanese cedar (Cryptomeria japonica D. Don) was decayed by the brown-rot fungus Fomitopsis palustris under bright and dark conditions. Scanning electron microscopy revealed the presence of mycelia inside the wood even after 1 week from the start of fungal exposure. Moreover, holes were observed in the torus after fungal exposure. Ruthenium red staining revealed that the pectin in pits was largely absent for 3 weeks. These events occurred before the mass loss of wood samples was confirmed at the early stage. Moreover, FpPG28A was more highly expressed at the hyphal front on a pectin-containing medium under dark conditions compared with bright conditions. This up-regulation under dark conditions indicated that the pectin decomposition ability was promoted inside the wood where light could not reach. In conclusion, we suggest that the brown-rot fungus completed its hyphal expansion within the wood via pectin decomposition in pits before holocellulose decomposition.

ARABIDOPSIS DEHISCENCE ZONE POLYGALACTURONASE 1 (ADPG1) releases latent defense signals in stems with reduced lignin content.

There is considerable interest in engineering plant cell wall components, particularly lignin, to improve forage quality and biomass properties for processing to fuels and bioproducts. However, modifying lignin content and/or composition in transgenic plants through down-regulation of lignin biosynthetic enzymes can induce expression of defense response genes in the absence of biotic or abiotic stress. Arabidopsis thaliana lines with altered lignin through down-regulation of hydroxycinnamoyl CoA:shikimate/quinate hydroxycinnamoyl transferase (HCT) or loss of function of cinnamoyl CoA reductase 1 (CCR1) express a suite of pathogenesis-related (PR) protein genes. The plants also exhibit extensive cell wall remodeling associated with induction of multiple cell wall-degrading enzymes, a process which renders the corresponding biomass a substrate for growth of the cellulolytic thermophile Caldicellulosiruptor bescii lacking a functional pectinase gene cluster. The cell wall remodeling also results in the release of size- and charge-heterogeneous pectic oligosaccharide elicitors of PR gene expression. Genetic analysis shows that both in planta PR gene expression and release of elicitors are the result of ectopic expression in xylem of the gene ARABIDOPSIS DEHISCENCE ZONE POLYGALACTURONASE 1 (ADPG1), which is normally expressed during anther and silique dehiscence. These data highlight the importance of pectin in cell wall integrity and the value of lignin modification as a tool to interrogate the informational content of plant cell walls.

Integration of enzymatic modification and ultrafiltration for the production of pectin fractions with highly potent antioxidant capacity as green valorization of sugar beet pulp.

Enzymatic hydrolysis of pectin followed by ultrafiltration of hydrolysate was applied with the aim to produce fractions with potent antioxidant capacity. Pectin was isolated from waste sugar beet pulp by acidic extraction, washed by diafiltration and concentrated by ultrafiltration. Enzymatic hydrolysis was performed with endo-polygalacturonase, and hydrolysate was processed by ultrafiltration into four fractions using membranes in series of decreasing cut-offs from 10 to 1 kDa. Hydrolysis with endo-polygalacturonase increased total antioxidant capacity by twofold in comparison to un-hydrolyzed pectin. Antioxidant capacity of all fractions was considerably higher than that of pectin-from 14.7 to 25-fold, for fraction containing fragments 10 kDa > Mw > 5 kDa and Mw < 1 kDa, respectively. Considerable increase of total antioxidant capacity of pectin through the integration of enzymatic modification and ultrafiltration fractionation indicated great potential of applied green protocol for the production of high-value hydrolysates of pectin from waste sugar beet pulp.

Genome-Wide Analysis of the Polygalacturonase Gene Family Sheds Light on the Characteristics, Evolutionary History, and Putative Function of Akebia trifoliata.

Polygalacturonase (PG) is one of the largest families of hydrolytic enzymes in plants. It is involved in the breakdown of pectin in the plant cell wall and even contributes to peel cracks. Here, we characterize PGs and outline their expression profiles using the available reference genome and transcriptome of Akebia trifoliata. The average length and exon number of the 47 identified AktPGs, unevenly assigned on 14 chromosomes and two unassembled contigs, were 5399 bp and 7, respectively. The phylogenetic tree of 191 PGs, including 47, 57, 51, and 36 from A. trifoliata, Durio zibethinus, Actinidia chinensis, and Vitis vinifera, respectively, showed that AktPGs were distributed in all groups except group G and that 10 AktPGs in group E were older, while the remaining 37 AktPGs were younger. Evolutionarily, all AktPGs generally experienced whole-genome duplication (WGD)/segmental repeats and purifying selection. Additionally, the origin of conserved domain III was possibly associated with a histidine residue (H) substitute in motif 8. The results of both the phylogenetic tree and expression profiling indicated that five AktPGs, especially AktPG25, could be associated with the cracking process. Detailed information and data on the PG family are beneficial for further study of the postharvest biology of A. trifoliata.

Genome-Wide Association Study Identifies a Plant-Height-Associated Gene OsPG3 in a Population of Commercial Rice Varieties.

Plant height is one of the most crucial components of plant structure. However, due to its complexity, the genetic architecture of rice plant height has not been fully elucidated. In this study, we performed a genome-wide association study (GWAS) to determine rice plant height using 178 commercial rice varieties and identified 37 loci associated with rice plant height (LAPH). Among these loci, in LAPH2, we identified a polygalacturonase gene, OsPG3, which was genetically and functionally associated with rice plant height. The rice plant exhibits a super dwarf phenotype when the knockout of the OsPG3 gene occurs via CRISPR-Cas9 gene-editing technology. RNA-Seq analysis indicated that OsPG3 modulates the expression of genes involved in phytohormone metabolism and cell-wall-biosynthesis pathways. Our findings suggest that OsPG3 plays a vital role in controlling rice plant height by regulating cell wall biosynthesis. Given that rice architecture is one of the most critical phenotypes in rice breeding, OsPG3 has potential in rice's molecular design breeding toward an ideal plant height.

Polygalacturonase45 cleaves pectin and links cell proliferation and morphogenesis to leaf curvature in Arabidopsis thaliana.

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.

Quantitative Genetic Analysis of Interactions in the Pepper-Phytophthora capsici Pathosystem.

The development of pepper cultivars with durable resistance to the oomycete Phytophthora capsici has been challenging due to differential interactions between the species that allow certain pathogen isolates to cause disease on otherwise resistant host genotypes. Currently, little is known about the pathogen genes involved in these interactions. To investigate the genetic basis of P. capsici virulence on individual pepper genotypes, we inoculated sixteen pepper accessions, representing commercial varieties, sources of resistance, and host differentials, with 117 isolates of P. capsici, for a total of 1,864 host-pathogen combinations. Analysis of disease outcomes revealed a significant effect of inter-species genotype-by-genotype interactions, although these interactions were quantitative rather than qualitative in scale. Isolates were classified into five pathogen subpopulations, as determined by their genotypes at over 60,000 single-nucleotide polymorphisms (SNPs). While absolute virulence levels on certain pepper accessions significantly differed between subpopulations, a multivariate phenotype reflecting relative virulence levels on certain pepper genotypes compared with others showed the strongest association with pathogen subpopulation. A genome-wide association study (GWAS) identified four pathogen loci significantly associated with virulence, two of which colocalized with putative RXLR effector genes and another with a polygalacturonase gene cluster. All four loci appeared to represent broad-spectrum virulence genes, as significant SNPs demonstrated consistent effects regardless of the host genotype tested. Host genotype-specific virulence variants in P. capsici may be difficult to map via GWAS with all but excessively large sample sizes, perhaps controlled by genes of small effect or by multiple allelic variants that have arisen independently. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Degradation of de-esterified pctin/homogalacturonan by the polygalacturonase GhNSP is necessary for pollen exine formation and male fertility in cotton.

The pollen wall exine provides a protective layer for the male gametophyte and is largely composed of sporopollenin, which comprises fatty acid derivatives and phenolics. However, the biochemical nature of the external exine is poorly understood. Here, we show that the male sterile line 1355A of cotton mutated in NO SPINE POLLEN (GhNSP) leads to defective exine formation. The GhNSP locus was identified through map-based cloning and confirmed by genetic analysis (co-segregation test and allele prediction using the CRISPR/Cas9 system). In situ hybridization showed that GhNSP is highly expressed in tapetum. GhNSP encodes a polygalacturonase protein homologous to AtQRT3, which suggests a function for polygalacturonase in pollen exine formation. These results indicate that GhNSP is functionally different from AtQRT3, the latter has the function of microspore separation. Biochemical analysis showed that the percentage of de-esterified pectin was significantly increased in the 1355A anthers at developmental stage 8. Furthermore, immunofluorescence studies using antibodies to the de-esterified and esterified homogalacturonan (JIM5 and JIM7) showed that the Ghnsp mutant exhibits abundant of de-esterified homogalacturonan in the tapetum and exine, coupled with defective exine formation. The characterization of GhNSP provides new understanding of the role of polygalacturonase and de-esterified homogalacturonan in pollen exine formation.

The ectomycorrhizal basidiomycete Laccaria bicolor releases a GH28 polygalacturonase that plays a key role in symbiosis establishment.

In ectomycorrhiza, root penetration and colonization of the intercellular space by symbiotic hyphae is thought to rely on the mechanical force that results from hyphal tip growth, enhanced by the activity of secreted cell-wall-degrading enzymes. Here, we characterize the biochemical properties of the symbiosis-induced polygalacturonase LbGH28A from the ectomycorrhizal fungus Laccaria bicolor. The transcriptional regulation of LbGH28A was measured by quantitative PCR (qPCR). The biological relevance of LbGH28A was confirmed by generating RNA interference (RNAi)-silenced LbGH28A mutants. We localized the LbGH28A protein by immunofluorescence confocal and immunogold cytochemical microscopy in poplar ectomycorrhizal roots. Quantitative PCR confirmed the induced expression of LbGH28A during ectomycorrhiza formation. Laccaria bicolor RNAi mutants have a lower ability to establish ectomycorrhiza, confirming the key role of this enzyme in symbiosis. The purified recombinant LbGH28A has its highest activity towards pectin and polygalacturonic acid. In situ localization of LbGH28A indicates that this endopolygalacturonase is located in both fungal and plant cell walls at the symbiotic hyphal front. These findings suggest that the symbiosis-induced pectinase LbGH28A is involved in the Hartig net formation and is an important determinant for successful symbiotic colonization.

Pectinolytic arsenal of Colletotrichum lindemuthianum and other fungi with different lifestyles.

AIM: To identify and analyse genes that encode pectinases in the genome of the fungus Colletotrichum lindemuthianum, evaluate the expression of these genes, and compare putative pectinases found in C. lindemuthianum with pectinases produced by other fungi and oomycetes with different lifestyles. METHODS AND RESULTS: Genes encoding pectinases in the genome of C. lindemuthianum were identified and analysed. The expression of these genes was analysed. Pectinases from C. lindemuthianum were compared with pectinases from other fungi that have different lifestyles, and the pectinase activity in some of these fungi was quantified. Fifty-eight genes encoding pectinases were identified in C. lindemuthianum. At least six types of enzymes involved in pectin degradation were identified, with pectate lyases and polygalacturonases being the most abundant. Twenty-seven genes encoding pectinases were differentially expressed at some point in C. lindemuthianum during their interactions with their host. For each type of pectinase, there were at least three isoenzyme groups. The number of pectinases present in fungi with different lifestyles seemed to be related more to the lifestyle than to the taxonomic relationship between them. Only phytopathogenic fungi showed pectate lyase activity. CONCLUSIONS: The collective results demonstrate the pectinolytic arsenal of C. lindemuthianum, with many and diverse genes encoding pectinases more than that found in other phytopathogens, which suggests that at least part of these pectinases must be important for the pathogenicity of the fungus C. lindemuthianum. SIGNIFICANCE AND IMPACT OF THE STUDY: Knowledge of these pectinases could further the understanding of the importance of this broad pectinolytic arsenal in the common bean infection and could be exploited for biotechnological purposes.

Comprehensive analysis of polygalacturonase genes offers new insights into their origin and functional evolution in land plants.

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.

Cell-Wall-Degrading Enzymes-Related Genes Originating from Rhizoctonia solani Increase Sugar Beet Root Damage in the Presence of Leuconostoc mesenteroides.

Sugar beet crown and root rot caused by Rhizoctonia solani is a major yield constraint. Root rot is highly increased when R. solani and Leuconostoc mesenteroides co-infect roots. We hypothesized that the absence of plant cell-wall-degrading enzymes in L. mesenteroides and their supply by R. solani during close contact, causes increased damage. In planta root inoculation with or without cell-wall-degrading enzymes showed greater rot when L. mesenteroides was combined with cellulase (22 mm rot), polygalacturonase (47 mm), and pectin lyase (57 mm) versus these enzymes (0-26 mm), R. solani (20 mm), and L. mesenteroides (13 mm) individually. Carbohydrate analysis revealed increased simpler carbohydrates (namely glucose + galactose, and fructose) in the infected roots versus mock control, possibly due to the degradation of complex cell wall carbohydrates. Expression of R. solani cellulase, polygalacturonase, and pectin lyase genes during root infection corroborated well with the enzyme data. Global mRNAseq analysis identified candidate genes and highly co-expressed gene modules in all three organisms that might be critical in host plant defense and pathogenesis. Targeting R. solani cell-wall-degrading enzymes in the future could be an effective strategy to mitigate root damage during its interaction with L. mesenteroides.

Applications of Innovative Non-Thermal Pulsed Electric Field Technology in Developing Safer and Healthier Fruit Juices.

The deactivation of degrading and pectinolytic enzymes is crucial in the fruit juice industry. In commercial fruit juice production, a variety of approaches are applied to inactivate degradative enzymes. One of the most extensively utilized traditional procedures for improving the general acceptability of juice is thermal heat treatment. The utilization of a non-thermal pulsed electric field (PEF) as a promising technology for retaining the fresh-like qualities of juice by efficiently inactivating enzymes and bacteria will be discussed in this review. Induced structural alteration provides for energy savings, reduced raw material waste, and the development of new products. PEF alters the α-helix conformation and changes the active site of enzymes. Furthermore, PEF-treated juices restore enzymatic activity during storage due to either partial enzyme inactivation or the presence of PEF-resistant isozymes. The increase in activity sites caused by structural changes causes the enzymes to be hyperactivated. PEF pretreatments or their combination with other nonthermal techniques improve enzyme activation. For endogenous enzyme inactivation, a clean-label hurdle technology based on PEF and mild temperature could be utilized instead of harsh heat treatments. Furthermore, by substituting or combining conventional pasteurization with PEF technology for improved preservation of both fruit and vegetable juices, PEF technology has enormous economic potential. PEF treatment has advantages not only in terms of product quality but also in terms of manufacturing. Extending the shelf life simplifies production planning and broadens the product range significantly. Supermarkets can be served from the warehouse by increasing storage stability. As storage stability improves, set-up and cleaning durations decrease, and flexibility increases, with only minor product adjustments required throughout the manufacturing process.