Cloning and Functional Identification of SlPG49 in Solanum lycopersicum

The modification and degradation of pectin in cell walls are necessary for the fruit softening process, which involves a series of pectin-modifying enzymes. Polygalacturonases (PGs) are a major group of pectin-hydrolyzing enzymes, which participate in fruit maturation, organ shedding, pollen development, and other processes by catalyzing the degradation of polygalacturonic acid. However, their function in plants has not yet been fully elucidated. In this paper, a full-length cDNA encoding SlPG49 was cloned from a tomato. Sequence alignment and phylogenetic analysis demonstrated that SlPG49 contains four typical conserved domains and belongs to clade E in PG classification. Quantitative real-time PCR analysis showed that SlPG49 was highly expressed in fruits during the softening stage, indicating that SlPG49 may be involved in fruit softening. Subcellular localization results revealed that SlPG49 was located in the cell membrane and the cell wall. In addition, an in vitro enzymatic activity assay confirmed that SlPG49 does have the ability to catalyze the hydrolysis of polygalacturonic acid. These results indicate that SlPG49 is a newly discovered PG gene involved in tomato fruit softening, and provide an experimental basis for elucidating the biological functions of plant PGs during fruit softening.

Preparation of polygalacturonic acid (PGA) to study virulence in Erwinia/Pectobacterium v1

This medium is used for the growth of Erwinia/Pectobacterium species to ensure that virulence genes are turned ON. These bacteria turn on virulence (plant cell-wall degrading enzymes = PCWDEs) in response to various environmental signals. One of these signals is of plant origin, and it is thought to allow the bacterium to determine whether it has located a potential plant host. These plant signals are sensed by the bacterial sensor/regulator KdgR.

Chemical modification of pectin and polygalacturonic acid: A critical review

Pectin, as a sustainable biopolymer with its two complementary functionalities (carboxyl and hydroxyl moieties) imparted in the α-1,4-galacturonic acid repeating unit, has gained increasing attention in the last few years. The interest in this ubiquitously occurring plant originating polysaccharide (PS) has shifted slowly from applications as a food additive to a broader range of potential applications in medicine, cosmetics, and other industries. Due to the increasing interest in alternatives for petrochemical materials, PSs as biomaterials have gained increasing attention in industrial processes in general. In the last decade, an increasing number of chemical transformations related to pectin have been published, and this is a prerequisite for the design of the structure and hence properties of novel biopolymer-based materials. This work aims to review the chemical modifications of pectin by covalent linkage of the last decade and analyze the materials obtained with these chemical methods critically.

Chemical modification of pectin and polygalacturonic acid: A critical review

Pectin, as a sustainable biopolymer with its two complementary functionalities (carboxyl and hydroxyl moieties) imparted in the α-1,4-galacturonic acid repeating unit, has gained increasing attention in the last few years. The interest in this ubiquitously occurring plant originating polysaccharide (PS) has shifted slowly from applications as a food additive to a broader range of potential applications in medicine, cosmetics, and other industries. Due to the increasing interest in alternatives for petrochemical materials, PSs as biomaterials have gained increasing attention in industrial processes in general. In the last decade, an increasing number of chemical transformations related to pectin have been published, and this is a prerequisite for the design of the structure and hence properties of novel biopolymer-based materials. This work aims to review the chemical modifications of pectin by covalent linkage of the last decade and analyze the materials obtained with these chemical methods critically.

Enhanced Biofilm Eradication and Reduced Cytotoxicity of a Novel Polygalacturonic and Caprylic Acid Wound Ointment Compared with Common Antiseptic Ointments

Antiseptic wound ointments are widely used to treat dermal wounds that are microbially contaminated. Polygalacturonic acid (PG)+caprylic acid (CAP) is a novel combination that has been shown to eradicate biofilms. We developed a novel PG+CAP ointment and compared the biofilm eradication capability and cytotoxicity of PG+CAP with that of commercially available antiseptic wound ointments. We used a well-established biofilm model to quantitatively assess the eradication of organisms following exposure to the wound ointments for 2 hours. PG+CAP ointment completely eradicated Candida albicans, multidrug-resistant Pseudomonas aeruginosa, and methicillin-resistant Staphylococcus aureus biofilms, whereas MediHoney, polyhexamethylene biguanide (PHMB), and benzalkonium chloride (BZK) ointments failed to eradicate all biofilms within 2 hours. We assessed cytotoxicity by exposing L-929 fibroblasts to extracts of each ointment; Trypan blue exclusion was used to assess cell viability, and Alamar blue conversion was used to assess metabolic function. After exposure to PG+CAP and MediHoney, fibroblast viability was 96.23% and 95.23%, respectively (Trypan blue), and was comparable to untreated cells (98.77%). PHMB and BZK showed reduced viability (83.25% and 77.83%, respectively, p < 0.05 ). Metabolic activity results followed a similar pattern. Cytotoxicity of PG+CAP ointment towards erythrocytes was comparable to saline. PG+CAP ointment seems to be safe and can rapidly eradicate microbial biofilm; thus, PG+CAP ointment merits further in vivo testing as a potential antimicrobial wound ointment.