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Basal stem rot (BSR) of oil palm is a disastrous disease caused by a white-rot fungus Ganoderma boninense Pat. Non-ribosomal peptides (NRPs) synthesized by non-ribosomal peptide synthetases (NRPSs) are a group of secondary metabolites that act as fungal virulent factors during pathogenesis in the host. In this study, we aimed to isolate NRPS gene of G. boninense strain UPMGB001 and investigate the role of this gene during G. boninense-oil palm interaction. The isolated NRPS DNA fragment of 8322 bp was used to predict the putative peptide sequence of different domains and showed similarity with G. sinense (85%) at conserved motifs of three main NRPS domains. Phylogenetic analysis of NRPS peptide sequences demonstrated that NRPS of G. boninense belongs to the type VI siderophore family. The roots of 6-month-old oil palm seedlings were artificially inoculated for studying NRPS gene expression and disease severity in the greenhouse. The correlation between high disease severity (50%) and high expression (67-fold) of G. boninense NRPS gene at 4 months after inoculation and above indicated that this gene played a significant role in the advancement of BSR disease. Overall, these findings increase our knowledge on the gene structure of NRPS in G. boninense and its involvement in BSR pathogenesis as an effector gene. [ABSTRACT FROM AUTHOR]

SUMMARY: Sargassum species are one of the major alginate‐producing seaweed species in Asian countries. Alginate is widely used in food, feed, pharmaceutical and medical industries as thickening and stabilizing agents. To establish a set of consistently expressed genes as reference genes for quantitative real‐time polymerase chain reaction (qRT‐PCR) studies of Sargassum polycystum (Fucales, Ochrophyta) in samples collected at two distinct time points from the field, four candidate reference genes, namely ribosomal protein L3 (RPL3), ribosomal protein S15 (RPS15), alpha‐tubulin (α‐TUB) and eukaryotic translation elongation factor 1 alpha (TEF1α), were analyzed using geNorm and NormFinder. The results showed that RPL3, α‐TUB and TEF1α were the most stable genes using both programs, whereas RPS15 gene was shown to be the least stable. Identification of stably expressed reference genes is crucial for qRT‐PCR studies to allow accurate quantification of target gene expression levels. In addition, the expression of key enzyme in the final step of alginate biosynthesis pathway mannuronan C5 epimerase‐SP01411 (MC5E‐SP01411) and mannuronan C5 epimerase‐SP02271 (MC5E‐SP02271) were differentially expressed in the seaweeds collected at two distinct time points from the field. To our knowledge, this is the first report on validation of reference genes for any Sargassum species. Our data provide a basis for the selection of reference genes for future biological research in related studies. [ABSTRACT FROM AUTHOR]

LEAFY (LFY) is an important regulator of plant's reproductive system, regulating the transition from vegetative growth to flowering, and also acts as an upstream regulator of floral homeotic MADS-box genes in Arabidopsis. Owing to its importance in flower development, oil palm LFY transcripts were isolated and the expression pattern was characterised to elucidate the role of LFY in oil palm. In addition, the gene expression pattern was analysed to determine a possible correlation of LFY to a type of floral abnormality in clonal palms termed mantling. In this study, three LFY transcripts were isolated from oil palm inflorescence tissue. The isolated cDNAs, OpLFY1, OpLFY2 and its splice variant, OpLFY2v were predicted to encode proteins each consisting of 430, 451 and 181 amino acids, respectively. OpLFY1 and OpLFY2 share 90% and 94% amino acid sequence identity to two different LFYs from Phoenix dactylifera, respectively. OpLFY1 was localised in all floral organ primordia. Quantitative polymerase chain reaction (qPCR) analysis revealed that OpLFY genes are expressed in shoot apical meristem and inflorescence tissues with the highest expression level. The expression of the OpLFY1 gene was significantly lower in stage 1 of inflorescence development in mantled palms compared with that of normal inflorescences, suggesting possible association of the gene with this somaclonal variation. [ABSTRACT FROM AUTHOR]

The infectious bursal disease (IBD) is an acute immunosuppressive viral disease that significantly affects the economics of the poultry industry. The IBD virus (IBDV) was known to infect B lymphocytes and activate macrophage and T lymphocytes, but there are limited studies on the impact of IBDV infection on chicken intraepithelial lymphocyte natural killer (IEL-NK) cells. This study employed an mRNA sequencing approach to investigate the early regulation of gene expression patterns in chicken IEL-NK cells after infection with very virulent IBDV strain UPM0081. A total of 12,141 genes were expressed in uninfected chicken IEL-NK cells, and most of the genes with high expression were involved in the metabolic pathway, whereas most of the low expressed genes were involved in the cytokine-cytokine receptor pathway. A total of 1,266 genes were differentially expressed (DE) at 3 day-post-infection (dpi), and these DE genes were involved in inflammation, antiviral response and interferon stimulation. The innate immune response was activated as several genes involved in inflammation, antiviral response and recruitment of NK cells to the infected area were up-regulated. This is the first study to examine the whole transcriptome profile of chicken NK cells towards IBDV infection and provides better insight into the early immune response of chicken NK cells. [ABSTRACT FROM AUTHOR]

• First report on the use of Discosoma red fluorescent protein (DsRED) - as visual reporter marker in oil palm cells. • Seven DsRED gene vectors driven by a different promoter were constructed and available for the scientific community. • The expression of DsRED in oil palm cells exhibited better photostability and brightness compared to GFP. Genetic modification of oil palm is being carried out to explore new avenues for improving and expanding the potential of oil palm. Multiple bottlenecks in delivering the DNA into oil palm cells and generating the transgenic oil palm required us to look into an alternative marker which could help us assess the efficiency of the transformation system, moreover at the early stage considering that oil palm is a slow growing plant. In this study, we have constructed seven transformation vectors carrying a gene encoding DsRED, each driven by a different promoter, i.e. plant constitutive promoter, oil palm constitutive promoter or oil palm tissue-specific promoter. The vectors were transformed into oil palm embryogenic calli via microprojectile bombardment and the red fluorescence signals were observed after 48 h. Based on the observation, the construct driven by the CaMV35S promoter produced the highest number of red fluorescent spots. The oil palm calli bombarded with pUbi-DsRED plasmid suffered the most number of red fluorescent spots losses from day three until day 42, as compared to other constructs. The red fluorescent signals of DsRED produced across all transformed samples appeared to be bright and very distinctive as compared to the background. [ABSTRACT FROM AUTHOR]

Modification of lipid composition in the mesocarp tissue of oil palm involves genetic manipulation of multiple genes. More than one mesocarp-preferential promoter is necessary for the expression of individual transgenes in the same plant to obviate transcriptional gene silencing. This study aimed to identify genes that are preferentially expressed in the mesocarp tissue and characterize selected candidate mesocarp-preferential promoters. Ten transcripts that were preferentially expressed in the mesocarp tissue were identified from the analysis of 82 transcriptome datasets of 12 different oil palm tissues. The expression of two candidate genes, MSP-C1 and MSP-C6 , was verified to be preferentially expressed in the mesocarp tissues and shown to have a low expression level in non-mesocarp tissues by reverse transcription quantitative real-time PCR (RT-qPCR). MSP-C6 promoter fragments of different lengths were transformed into tomato plants for further characterization. Both unripe and ripe fruits of transgenic tomato plants transformed with a construct harboring the MSP-C6-F1 (2014 bp) promoter were shown to have high beta-glucuronidase (GUS) activities. The findings of this study suggest the potential applications of the MSP-C6 promoter as a molecular tool for genetic engineering of novel traits in fruit crops. • Ten mesocarp-preferential transcripts were identified from the analysis of 82 oil palm transcriptome datasets. • Two candidate genes were verified to be preferentially expressed in the oil palm mesocarp tissues. • The MSP-C6-F1 (2014 bp) promoter fragment was shown to be able to drive preferential gene expression in tomato fruits. • Characterization of mesocarp-specific promoters contribute to future genetic manipulation of oil synthesis in oil palm. [ABSTRACT FROM AUTHOR]

Abstract: Glucanases are enzymes that hydrolyze a variety β-d-glucosidic linkages. Plant β-1,3-glucanases are able to degrade fungal cell walls; and promote the release of cell-wall derived fungal elicitors. In this study, three full-length cDNA sequences encoding oil palm (Elaeis guineensis) glucanases were analyzed. Sequence analyses of the cDNA sequences suggested that EgGlc1-1 is a putative β-d-glucan exohydolase belonging to glycosyl hydrolase (GH) family 3 while EgGlc5-1 and EgGlc5-2 are putative glucan endo-1,3-β-glucosidases belonging to GH family 17. The transcript abundance of these genes in the roots and leaves of oil palm seedlings treated with Ganoderma boninense and Trichoderma harzianum was profiled to investigate the involvement of these glucanases in oil palm during fungal infection. The gene expression of EgGlc1-1 in the root of oil palm seedlings was increased by T. harzianum but suppressed by G. boninense; while the gene expression of both EgGlc5-1 and EgGlc5-2 in the roots of oil palm seedlings was suppressed by G. boninense or/and T. harzianum. [Copyright &y& Elsevier]