Differential proteomic study of oil palm leaves in response to in vitro inoculation with pathogenic and non-pathogenic Ganoderma spp.

Basal stem rot is an aggressive disease in oil palm caused by Ganoderma species. The disease threatens the commercial oil palm plantations of South East Asia, especially in Malaysia. In order to understand the mechanism involved in the early stage of interaction between Ganoderma spp. and its host at systemic level, proteomic analysis of oil palm leaves was conducted on protein samples collected over 72 hours during inoculation with pathogenic Ganoderma boninense and non-pathogenic Ganoderma tornatum. A total of 82 proteins resolved during two-dimensional gel electrophoresis with significant differences in the spot abundance. However, only 24 differentially expressed proteins in response to Ganoderma spp. inoculations were successfully identified by mass spectrophotometry as compared to the non-inoculated control. These proteins are mainly involved in photosynthesis, signalling, stress/defense, energy and metabolism regulation. Changes in relative abundance of these proteins suggest an important role in disease susceptibility. Most proteins showed altered abundance in response to both G. boninense and G. tornatum, while some proteins were only affected by either G. boninense or G. tornatum. The putative role of the identified proteins in oil palm leaves during the interaction with both Ganoderma spp. is discussed

Ability of endophytic fungi isolated from Nepenthes ampullaria to degrade polyurethane

Aims: Waste electric and electronic equipment (WEEE) are among the fastest growing waste products worldwide and solutions to their remediation are urgently needed. Bioremediation is a green approach that is helpful to minimize environmental pollution associated with Electronic waste (E-waste). The present study aimed at exploring the potential of endophytic fungi from Nepenthes ampullaria for bioremediation purposes of the plastic component in E-waste, polyurethane (PUR) polymers. Methodology and results: Endophytic fungal isolates were assessed for their ability to degrade PUR as well as their ability to utilise PUR as sole carbon source. Nine (9) out of 150 isolates demonstrated the ability to efficiently degrade polyurethane in solid medium and the top three (3) isolates were able to grow on PUR as the only carbon source. These three isolates were identified using ITS1 and ITS4 and found to be closely related to the genus Pestalotiopsis. The top two of the three isolates were then assessed for their esterase enzyme activity as well as changes in their proteome when grown with and without PUR. The highest enzymatic activity was found to be 1850.4 U/mL when tested using pnitrophenol acetate as the substrate. Analyses of the 2-dimensional electrophoresis profile revealed changes in the abundance of proteins when treated with polyurethane. Conclusion, significance and impact of study: This study is to our knowledge the first on endophytes isolated from N. ampullaria that can degrade PUR, and also their proteomes. Results obtained from this study can in the future help to reduce polyurethane wastes. Besides degrading PUR polymer, endophytic fungi produce potential valuable proteins that may find broad applications in bioremediation applications

Standardized bioassays: an improved method for studying Fusarium oxysporum f. sp. cubense race 4 (FocR4) pathogen stress response in Musa acuminata cv. ‘Berangan’

To date, there is no standardized Fusarium bioassay protocol established owing partly to the wide variety of Fusarium oxysporum f. sp. cubense (Foc) isolates and banana cultivars present. Thus, validation of the infection parameters is deemed essential prior to each bioassay experiment. In the current study, a simple standardized workflow was developed based on available assays for testing Fusarium wilt disease response in Musa acuminata using M. acuminata cv. ‘Berangan’ of tissue-culture origin as a model. The phenotypic assays were able to detect external disease symptoms less than one week post-inoculation, while the molecular approach using RT-qPCR identified differential expression of catalase (CAT), pathogenesis-related 10 (PR10), phenylalanine ammonia-lyase (PAL) and xylanase (XYL) genes as early as day 0. The transcript levels of PR10 and XYL fluctuated over 4 days of Foc Race 4 (FocR4 C1 HIR isolate) infection while the expression of CAT steadily increased over time. In contrast, PAL was highly upregulated at 2 days post-inoculation. These signature changes suggest that all genes tested might be involved in the early defense response of ‘Berangan’ plants against FocR4 infection. ‘Berangan’ cultivar was found to be highly susceptible to Foc Race 4 (C1 HIR isolate) with leaf symptoms index (LSI) and rhizome discoloration index (RDI) scores of 4.257 and 5.971, respectively. The procedure elaborated in this study can be used as a reference Foc bioassay for reproducible and comparable results possibly across cultivars and test isolates due to its simple steps aided by integration of phenotypic and molecular approach

Comparative proteomic analysis on fruit ripening processes in two varieties of tropical mango (Mangifera indica)

Mango (Mangifera indica L.) is an economically important fruit. However, the marketability of mango is affected by the perishable nature and short shelf-life of the fruit. Therefore, a better understanding of the mango ripening process is of great importance towards extending its postharvest shelf life. Proteomics is a powerful tool that can be used to elucidate the complex ripening process at the cellular and molecular levels. This study utilized 2-dimensional gel electrophoresis (2D-GE) coupled with MALDI-TOF/TOF to identify differentially abundant proteins during the ripening process of the two varieties of tropical mango, Mangifera indica cv. ‘Chokanan’ and Mangifera indica cv ‘Golden Phoenix’. The comparative analysis between the ripe and unripe stages of mango fruit mesocarp revealed that the differentially abundant proteins identified could be grouped into the three categories namely, ethylene synthesis and aromatic volatiles, cell wall degradation and stress-response proteins. There was an additional category for differential proteins identified from the ‘Chokanan’ variety namely, energy and carbohydrate metabolism. However, of all the differential proteins identified, only methionine gamma-lyase was found in both ‘Chokanan’ and ‘Golden Phoenix’ varieties. Six differential proteins were selected from each variety for validation by analysing their respective transcript expression using reverse transcription-quantitative PCR (RT-qPCR). The results revealed that two genes namely, glutathione S-transferase (GST) and alpha-1,4 glucan phosphorylase (AGP) were found to express in concordant with protein abundant. The findings will provide an insight into the fruit ripening process of different varieties of mango fruits, which is important for postharvest management

Mycopharmaceuticals and nutraceuticals: promising agents to improve human well-being and life quality

Fungi, especially edible mushrooms, are considered as high-quality food with nutritive and functional values. They are of considerable interest and have been used in the synthesis of nutraceutical supplements due to their medicinal properties and economic significance. Specific fungal groups, including predominantly filamentous endophytic fungi from Ascomycete phylum and several Basidiomycetes, produce secondary metabolites (SMs) with bioactive properties that are involved in the antimicrobial and antioxidant activities. These beneficial fungi, while high in protein and important fat contents, are also a great source of several minerals and vitamins, in particular B vitamins that play important roles in carbohydrate and fat metabolism and the maintenance of the nervous system. This review article will summarize and discuss the abilities of fungi to produce antioxidant, anticancer, antiobesity, and antidiabetic molecules while also reviewing the evidence from the last decade on the importance of research in fungi related products with direct and indirect impact on human health

Identification of a partial oil palm polygalacturonase-inhibiting protein (EgPGIP) gene and its expression during basal stem rot infection caused by Ganoderma boninense

Basal stem rot disease (BSR) is a common and serious fungal disease of  the oil palm caused by Ganoderma boninense. This fungal disease  infects thousands of hectares of plantings in Southeast Asia every year causing not only yield but also tree losses. A natural plant self defence mechanism against fungal infection is the production of fungal resistance protein. A fungal resistance gene that has been reported previously in  other monocotyledonous plants such as rice and barley is polygalacturonase-inhibiting protein (PGIP) gene, a plant defence cell  wall glycoprotein that has been shown to inhibit the activity of fungal endopolygalacturonase (endo-PGs) and modulate their activity and has the potential to be developed as a disease or resistance biomarker for  the oil palm. The identification and isolation of this gene in oil palm  allowed for the study of its differential expression during the fungal  infection. The oil palm PGIP gene (EgPGIP) has between 60-100% similarities with the database sequence of PGIP from other  monocotyledons. Interestingly, we found that the expression of EgPGIP gene measured using Real-Time PCR showed that the expression level of EgPGIP in infected oil palm was temporally down regulated. The results suggest that, down regulation of the EgPGIP is related to the  establishment of infection by G. boninense.Keywords: Polygalacturonase-inhibiting protein, basal stem root,  ganoderma infection, oil pal

Identification of a partial oil palm polygalacturonase-inhibiting protein (EgPGIP) gene and its expression during basal stem rot infection caused by Ganoderma boninense

Basal stem rot disease (BSR) is a common and serious fungal disease of  the oil palm caused by Ganoderma boninense. This fungal disease  infects thousands of hectares of plantings in Southeast Asia every year causing not only yield but also tree losses. A natural plant self defence mechanism against fungal infection is the production of fungal resistance protein. A fungal resistance gene that has been reported previously in  other monocotyledonous plants such as rice and barley is polygalacturonase-inhibiting protein (PGIP) gene, a plant defence cell  wall glycoprotein that has been shown to inhibit the activity of fungal endopolygalacturonase (endo-PGs) and modulate their activity and has the potential to be developed as a disease or resistance biomarker for  the oil palm. The identification and isolation of this gene in oil palm  allowed for the study of its differential expression during the fungal  infection. The oil palm PGIP gene (EgPGIP) has between 60-100% similarities with the database sequence of PGIP from other  monocotyledons. Interestingly, we found that the expression of EgPGIP gene measured using Real-Time PCR showed that the expression level of EgPGIP in infected oil palm was temporally down regulated. The results suggest that, down regulation of the EgPGIP is related to the  establishment of infection by G. boninense.Keywords: Polygalacturonase-inhibiting protein, basal stem root,  ganoderma infection, oil pal

Determination of the use of Lactobacillus plantarum and Propionibacterium freudenreichii application on fermentation profile and chemical composition of corn silage

The potential of laser light backscattering imaging was investigated for monitoring color parameters of seeded and seedless watermelons during storage. Two watermelon cultivars were harvested and stored for 3 weeks with seven measuring storage days (0, 4, 8, 12, 15, 18, and 21). The color parameters of watermelons were monitored using the conventional colorimetric methods (L*, a*, b*, C*, H*, and ∆E*) and laser light backscattering imaging system. A laser diode emitting at 658 nm and 30 mW power was used as a light source to obtain the backscattering image. The backscattering images were evaluated by the extraction of backscattering parameters based on the mean pixel values. The results showed that a good color prediction was achieved by the seedless watermelon with the R2 are all above 0.900. Thus, the application of the laser light backscattering imaging can be used for evaluating the color parameters of watermelons during the storage period