EgMADS3 directly regulates EgLPAAT to mediate medium-chain fatty acids (MCFA) anabolism in the mesocarp of oil palm.

KEY MESSAGE: EgMADS3, a pivotal transcription factor, positively regulates MCFA accumulation via binding to the EgLPAAT promoter, advancing lipid content in mesocarp of oil palm. Lipids function as the structural components of cell membranes, which serve as permeable barriers to the external environment of cells. The medium-chain fatty acid in the stored lipids of plants is an important renewable energy. Most research on MCFA production in plant lipid synthesis is based on biochemical methods, and the importance of transcriptional regulation in MCFA synthesis and its incorporation into TAGs needs further research. Oil palm is the most productive oil crop in the world and has the highest productivity among the main oil crops. In this study, the MADS transcription factor (EgMADS3) in the mesocarp of oil palm was characterized. Through the VIGS-virus induced gene silencing, it was determined that the potential target gene of EgMADS3 was related to the biosynthesis of medium-chain fatty acid (MCFA). Transient transformation in protoplasts and qRT-PCR analysis showed that EgMADS3 positively regulated the expression of EgLPAAT. The results of the yeast one-hybrid assays and EMSA indicated the interaction between EgMADS3 and EgLPAAT promoter. Through genetic transformation and fatty acid analysis, it is concluded that EgMADS3 directly regulates the mid-chain fatty acid synthesis pathway of the potential target gene EgLPAAT, thus promotes the accumulation of MCFA and improves the total lipid content. This study is innovative in the functional analysis of the MADS family transcription factor in the metabolism of medium-chain fatty acids (MCFA) of oil palm, provides a certain research basis for improving the metabolic pathway of chain fatty acids in oil palm, and improves the synthesis of MCFA in plants. Our results will provide a reference direction for further research on improving the oil quality through biotechnology of oil palm.

Catalase (CAT) Gene Family in Oil Palm (Elaeis guineensis Jacq.): Genome-Wide Identification, Analysis, and Expression Profile in Response to Abiotic Stress.

Catalases (CATs) play crucial roles in scavenging H2O2 from reactive oxygen species, controlling the growth and development of plants. So far, genome-wide identification and characterization of CAT genes in oil palm have not been reported. In the present study, five EgCAT genes were obtained through a genome-wide identification approach. Phylogenetic analysis divided them into two subfamilies, with closer genes sharing similar structures. Gene structure and conserved motif analysis demonstrated the conserved nature of intron/exon organization and motifs among the EgCAT genes. Several cis-acting elements related to hormone, stress, and defense responses were identified in the promoter regions of EgCATs. Tissue-specific expression of EgCAT genes in five different tissues of oil palm was also revealed by heatmap analysis using the available transcriptome data. Stress-responsive expression analysis showed that five EgCAT genes were significantly expressed under cold, drought, and salinity stress conditions. Collectively, this study provided valuable information on the oil palm CAT gene family and the validated EgCAT genes can be used as potential candidates for improving abiotic stress tolerance in oil palm and other related crops.

Metabonomics and Transcriptomic Analysis of Free Fatty Acid Synthesis in Seedless and Tenera Oil Palm.

Oil palm, a tropical woody oil crop, is widely used in food, cosmetics, and pharmaceuticals due to its high production efficiency and economic value. Palm oil is rich in free fatty acids, polyphenols, vitamin E, and other nutrients, which are beneficial for human health when consumed appropriately. Therefore, investigating the dynamic changes in free fatty acid content at different stages of development and hypothesizing the influence of regulatory genes on free fatty acid metabolism is crucial for improving palm oil quality and accelerating industry growth. LC-MS/MS is used to analyze the composition and content of free fatty acids in the flesh after 95 days (MS1 and MT1), 125 days (MS2 and MT2), and 185 days (MS3 and MT3) of Seedless (MS) and Tenera (MT) oil palm species fruit pollination. RNA-Seq was used to analyze the expression of genes regulating free fatty acid synthesis and accumulation, with differences in genes and metabolites mapped to the KEGG pathway map using the KEGG (Kyoto encyclopedia of genes and genomes) enrichment analysis method. A metabolomics study identified 17 types of saturated and 13 types of unsaturated free fatty acids during the development of MS and MT. Transcriptomic research revealed that 10,804 significantly different expression genes were acquired in the set differential gene threshold between MS and MT. The results showed that FabB was positively correlated with the contents of three main free fatty acids (stearic acid, myristate acid, and palmitic acid) and negatively correlated with the contents of free palmitic acid in the flesh of MS and MT. ACSL and FATB were positively correlated with the contents of three main free fatty acids and negatively correlated with free myristate acid. The study reveals that the expression of key enzyme genes, FabB and FabF, may improve the synthesis of free myristate in oil palm flesh, while FabF, ACSL, and FATB genes may facilitate the production of free palmitoleic acid. These genes may also promote the synthesis of free stearic acid and palmitoleic acid in oil palm flesh. However, the FabB gene may inhibit stearic acid synthesis, while ACSL and FATB genes may hinder myristate acid production. This study provides a theoretical basis for improving palm oil quality.

Peach palm shells (Bactris gasipaes Kunth) bioconversion by Lentinula edodes: Potential as new bioproducts for beef cattle feeding.

This paper aims to develop and assess the in vitro effects on ruminal fermentation and greenhouse gas parameters of new bioproducts for beef cattle diets, carried out by solid-state fermentation of peach palm shells colonized by Lentinula edodes (SSF) and after Shiitake mushroom cultivation in axenic blocks (SMS). In vitro experiments were performed to assess the in vitro gas production, digestibility, and fiber degradation of formulated total diets. Bioproducts presented high ß-glucans (9.44---11.27 %) and protein (10.04---8.35 %) contents, as well as similar digestibility to conventional diets. SMS diet had the lowest methane and carbon dioxide (19.1 and 84.1 mM/g OM) production, and the SSF diet presented lower carbon dioxide production (98.9 mM/g OM) than other diets, whereas methane was similar. This study highlighted a sustainable use of byproducts for beef cattle diets, promising for digestibility, nutritional value, ß-glucans incorporation, and environmental impact mitigation, favoring the circular bioeconomy.

Ameliorating the impairment of glucose utilization in a high-fat diet-induced obesity model through the consumption of Tucum-do-Cerrado (Bactris Setosa Mart.).

INTRODUCTION: We evaluated the effect of Tucum-do-Cerrado on glucose metabolism homeostasis and its relationship with redox-inflammatory responses in a high-fat (HF) diet-induced obesity model. RESULTS: The HF diet increased energy intake, feed efficiency, body weight, muscle and hepatic glycogen, insulin, homeostatic model assessment of insulin resistance (HOMA IR) and beta (ß)-cell function, and gut catalase (CAT) activity, and decreased food intake, hepatic glutathione reductase (GR), glutathione peroxidase (GPX), glutathione S-transferase (GST), and superoxide dismutase (SOD) activities, hepatic phosphoenolpyruvate carboxykinase 1 (Pck1), and intestinal solute carrier family 5 member 1 (Slc5a1) mRNA levels compared with the control diet. However, the HF diet with Tucum-do-Cerrado decreased hepatic glycogen, and increased hepatic GR activity, hepatic Slc2a2 mRNA levels and serum Tnfa compared with the HF diet. Tucum-do-Cerrado decreased muscle glycogen, intestinal CAT and GPX activities, muscle PFK-1 and HK activities, and increased hepatic protein (CARB) and intestinal lipid (MDA) oxidation, hepatic GST activity, serum antioxidant potential, hepatic phosphofructokinase-1 (PFK-1) activity, intestinal solute carrier family 2 member 2 (Slc2a2), tumor necrosis factor (Tnf), interleukin-1 beta (Il1b), muscle protein kinase AMP-activated alpha 1 (Prkaa1), solute carrier family 2 member 2 (Slc2a2) mRNA levels, and serum interleukin-6 (IL-6) levels, regardless of diet type. CONCLUSION: Tucum-do-Cerrado consumption may ameliorate impaired glucose utilization in a HF diet-induced obesity model by increasing liver and muscle glucose uptake and oxidation. These data suggest that Tucum-do-Cerrado consumption improves muscle glucose oxidation in non-obese and obese rats. This response may be related to the improvement in the total antioxidant capacity of rats.

Transcriptional effects of carbon and nitrogen starvation on Ganoderma boninense, an oil palm phytopathogen.

BACKGROUND: Ganoderma boninense is a phytopathogen of oil palm, causing basal and upper stem rot diseases. METHODS: The genome sequence was used as a reference to study gene expression during growth in a starved carbon (C) and nitrogen (N) environment with minimal sugar and sawdust as initial energy sources. This study was conducted to mimic possible limitations of the C-N nutrient sources during the growth of G. boninense in oil palm plantations. RESULTS: Genome sequencing of an isolate collected from a palm tree in West Malaysia generated an assembly of 67.12 Mb encoding 19,851 predicted genes. Transcriptomic analysis from a time course experiment during growth in this starvation media identified differentially expressed genes (DEGs) that were found to be associated with 29 metabolic pathways. During the active growth phase, 26 DEGs were related to four pathways, including secondary metabolite biosynthesis, carbohydrate metabolism, glycan metabolism and mycotoxin biosynthesis. G. boninense genes involved in the carbohydrate metabolism pathway that contribute to the degradation of plant cell walls were up-regulated. Interestingly, several genes associated with the mycotoxin biosynthesis pathway were identified as playing a possible role in pathogen-host interaction. In addition, metabolomics analysis revealed six metabolites, maltose, xylobiose, glucooligosaccharide, glycylproline, dimethylfumaric acid and arabitol that were up-regulated on Day2 of the time course experiment. CONCLUSIONS: This study provides information on genes expressed by G. boninense in metabolic pathways that may play a role in the initial infection of the host.

Identification of oil palm cis-regulatory elements based on DNA free energy and single nucleotide polymorphism density.

Transcription control through cis-regulatory elements (CREs) is one of important regulators of gene expression. This study aimed to identify the location of CREs in oil palm (Elaeis guineensis Jacq.) using the combination of DNA free energy and single nucleotide polymorphism (SNP) density approaches. Promoter region sequences were extracted oil palm genome spanning from 1500 nucleotides (nt) upstream to 1000 nt downstream of every annotated transcription start sites (TSS). Free energy profiles of each promoter region were calculated using PromPredict software. Raw reads from the deep sequencing of 59 oil palm origins were used to calculate SNP density of each promoter region. The result showed that the average free energy (AFE) on the upstream region of TSS is about 1.5 kcal/mol higher compared to the downstream region. Using DNA free energy method, 16,281 regions of CREs were predicted. Most of predicted CREs was located between 1 and 500 nt upstream of TSS. Anti-correlation pattern between free energy and SNP density was observed on the predicted regions of CREs. This anti-correlated pattern was also observed on an experimentally determined promoter of the oil palm metallothionein gene, EgMSP1. Considering the increasing use of promoter information on plant biotechnology, an easy and accurate promoter prediction using the combination of free energy and SNP density method could be recommended.

Identification of microRNAs involved in the Phosphate starvation response in Oil Palm (Elaeis guineensis Jacq.).

BACKGROUND: Plant microRNA, often known as miRNA, is a novel form of gene expression regulator that is known to play a significant role in phosphate starvation. The identification of microRNAs involved in the response to phosphate starvation in oil palms is beneficial for breeding programs. METHOD: The main nursery stage seedlings of two oil palm progenies were treated with three different fertiliser namely: complete fertiliser with urea, P2O5, K2O, and MgO based on the standard procedure as a control (C); fertiliser with urea, K2O, MgO without P2O5 (P0); and no fertiliser (F0) for 24 weeks. A total of six oil palm roots were subjected to RNA isolation, followed by miRNA sequencing using the Illumina HiSeq 4000 platform, and all reads were computationally analysed. RESULTS: In total, 119 potential miRNAs related to 5,891 genes were identified. The P-specific miRNAs were assumed based on the miRNAs that identified without P fertilizer treatment, resulted of twenty miRNA sequences in the treatment comparison of (C vs P0) vs (C vs F0). Those 20 miRNA sequences were grouped into 9 families, namely EgmiR319; EgmiR399; EgmiR396; EgmiR172; EgmiR156; EgmiR157; miR5648; miR5645; and EgmiRNA_unidentified. Two miRNAs were selected for RT-qPCR validation, namely EgMir399 and EgMir172. Their expression pattern was similar with the RNA sequencing results and shown opposite expression pattern with their target genes, UBC E2 24 and APETALA2, respectively. CONCLUSIONS: The nine micro RNA families was identified in oil palm root tissue at phosphate starvation.

Identification and Analysis of MADS-Box Genes Expressed in the Mesocarp of Oil Palm Fruit (Elaeis guineensis Jacq.).

Oil palm (Elaeis guineensis) is the most important tropical oil-bearing crop species worldwide. MADS-box proteins, which play crucial roles in plant growth and development and are involved in various physiological and biochemical processes, compose one of the largest families of plant transcription factors. In this study, 42 MADS-box genes were screened from the mesocarp transcriptome database of oil palm fruit, and their phylogenetic relationships with Arabidopsis thaliana MADS-box genes were analyzed. Based on the results, MADS-box genes from oil palm mesocarp were classified into four groups: MIKCc-type, MIKC*-type, Mα-type, and Mγ-type MADS-box genes. Members of the subfamilies were classified according to the presence of three specific protein motifs. To explore the differential expression of the MADS-box genes, the dynamic expression of all selected MADS-box genes in oil palm was measured by RNA-seq. The high expression of specific MADS-box genes in the mesocarp of oil palm during different developmental stages indicates that those genes may play important roles in the cell division of and metabolite accumulation in the fruit and could become important targets for fruit development and oil accumulation research in oil palm.

Induced expression of Ganoderma boninense Lanosterol 14α-Demethylase (ERG11) during interaction with oil palm.

BACKGROUND: The basidiomycete fungus, Ganoderma boninense is the main contributor to oil palm Basal Stem Rot (BSR) in Malaysia and Indonesia. Lanosterol 14α-Demethylase (ERG11) is a key enzyme involved in biosynthesis of ergosterol, which is an important component in the fungal cell membrane. The Azole group fungicides are effective against pathogenic fungi including G. boninense by inhibiting the ERG11 activity. However, the work on molecular characterization of G. boninense ERG11 is still unavailable today. METHODS AND RESULTS: This study aimed to isolate and characterize the full-length cDNA encoding ERG11 from G. boninense. The G. boninense ERG11 gene expression during interaction with oil palm was also studied. A full-length 1860 bp cDNA encoding ERG11 was successfully isolated from G. boninense. The G. boninense ERG11 shared 91% similarity to ERG11 from other basidiomycete fungi. The protein structure homology modeling of GbERG11 was analyzed using the SWISS-MODEL workspace. Southern blot and genome data analyses showed that there is only a single copy of ERG11 gene in the G. boninense genome. Based on the in-vitro inoculation study, the ERG11 gene expression in G. boninense has shown almost 2-fold upregulation with the presence of oil palm. CONCLUSION: This study provided molecular information and characterization study on the G. boninense ERG11 and this knowledge could be used to design effective control measures to tackle the BSR disease of oil palm.

Integrative Omics Analysis of Three Oil Palm Varieties Reveals (Tanzania × Ekona) TE as a Cold-Resistant Variety in Response to Low-Temperature Stress.

Oil palm (Elaeis guineensis Jacq.) is an economically important tropical oil crop widely cultivated in tropical zones worldwide. Being a tropical crop, low-temperature stress adversely affects the oil palm. However, integrative leaf transcriptomic and proteomic analyses have not yet been conducted on an oil palm crop under cold stress. In this study, integrative omics transcriptomic and iTRAQ-based proteomic approaches were employed for three oil palm varieties, i.e., B × E (Bamenda × Ekona), O × G (E. oleifera × Elaeis guineensis), and T × E (Tanzania × Ekona), in response to low-temperature stress. In response to low-temperature stress at (8 °C) for 5 days, a total of 5175 up- and 2941 downregulated DEGs in BE-0_VS_BE-5, and a total of 3468 up- and 2443 downregulated DEGs for OG-0_VS_OG-5, and 3667 up- and 2151 downregulated DEGs for TE-0_VS_TE-5 were identified. iTRAQ-based proteomic analysis showed 349 up- and 657 downregulated DEPs for BE-0_VS_BE-5, 372 up- and 264 downregulated DEPs for OG-0_VS_OG-5, and 500 up- and 321 downregulated DEPs for TE-0_VS_TE-5 compared to control samples treated at 28 °C and 8 °C, respectively. The KEGG pathway correlation of oil palm has shown that the metabolic synthesis and biosynthesis of secondary metabolites pathways were significantly enriched in the transcriptome and proteome of the oil palm varieties. The correlation expression pattern revealed that TE-0_VS_TE-5 is highly expressed and BE-0_VS_BE-5 is suppressed in both the transcriptome and proteome in response to low temperature. Furthermore, numerous transcription factors (TFs) were found that may regulate cold acclimation in three oil palm varieties at low temperatures. Moreover, this study identified proteins involved in stresses (abiotic, biotic, oxidative, and heat shock), photosynthesis, and respiration in iTRAQ-based proteomic analysis of three oil palm varieties. The increased abundance of stress-responsive proteins and decreased abundance of photosynthesis-related proteins suggest that the TE variety may become cold-resistant in response to low-temperature stress. This study may provide a basis for understanding the molecular mechanism for the adaptation of oil palm varieties in response to low-temperature stress in China.

Variation of the Antioxidative Defense in Elaeis guineensis Jacq. Facing Bud Rot Disease in the Coastal Area of Ecuador.

Elaeis guineensis Jacq. has gained a reputation in the food industry as an incredible crop capable of supplying the world's largest edible oil production. In Ecuador, an important oil palm-producing country, this crop is affected in a high percentage by the bud rot disease, which is responsible for palm death. The main objective of the investigation was dedicated to understanding the palm defense mechanism facing bud rot disease, translated in the induction of reactive oxygen species, activation of defensive machinery comprising enzymatic and non-enzymatic antioxidative components, secondary metabolites, carotenoids accumulation in the palm during all stages of disease infection. For this, a survey was conducted in different oil palm plantations in the Esmeraldas province, one of the most representative for its highest incidence of bud rot disease. The survey completed DPPH, FRAP, ABTS, and other spectrophotometric analyses to underline the biochemical, biological, and physiological palm response front of bud rot incidence. The palm defense strategy in each disease stage could be represented by the phenolic compound's involvement, an increment of antioxidant activity, and the high enzymatic activity of phenylalanine ammonia-lyase (PAL). The results of the investigation made understandable the palm defense strategy front of this disease, respectively, the antioxidative defense and the palm secondary compounds involved.

Evaluation of the preventive potential of graded dietary inclusion of Hyphaene thebaica (Linn) fruit in rat model of colon carcinogenesis.

The preventive effect of Hyphaene thebaica fruit in colon carcinogenesis was evaluated in Wistar rats at 0, 2.5, 5 and 10% inclusion rates for twelve weeks with concomitant 72-h intra-rectal N-methyl-N-nitrosourea (MNU) instillations. Indices of antioxidant status and carcinogenesis were analyzed using spectrophotometric, ELISA, histological and immunohistochemical techniques. The fruit protected against lipid peroxidation and level of early biomarkers of colon carcinogenesis, accompanied by decrease in some endogenous antioxidant enzymes functionality. It also prevented colon tissues against MNU-induced severe inflammations and damage to the mutL-homolog 1 (MLH1) gene. There was significant negative correlation between endogenous antioxidant enzyme activities and carcinoembryonic antigen (CEA) as well as lipid peroxidation, but relationship between total polyphenols and percentage expression of MLH1 proteins as well as endogenous antioxidant enzyme activities was positive. These results validate the folkloric use of H. thebaica fruit in the management of colorectal disorders. PRACTICAL APPLICATIONS: Hyphaene thebaica fruit which is widely consumed in northern Nigeria and other countries of sub-Saharan Africa is rich in fiber and antioxidant polyphenols. These two classes of compounds have demonstrated capacity to prevent colorectal cancer and cancer of other sites. Therefore, the validated protective Hyphaene thebaica fruit suggests that it can be processed for inclusion in beverages/diets as functional foods for prevention and management of colorectal disorders.

Improved long-chain omega-3 polyunsaturated fatty acids in sago palm weevil (Rhynchophorus ferrugineus) larvae by dietary fish oil supplementation.

The nutritional values of sago palm weevil larvae (SPWL) reared on mixed plant-based diets (ground sago palm trunk (GS), cornmeal, rice bran, soybean, and perilla seed), containing different levels of dietary fish oil (FO) were compared to those reared on commercial pig feed (PF) and GS. Increased FO content resulted in an increase in ω-3 fatty acids (FA) in SPWL (p < 0.05), especially α-linolenic acid and eicosapentaenoic acid. When fed FO-fortified diets instead of PF, the health-promoting indices of the SPWL lipid improved significantly (e.g., decreased ω-6/ω-3 ratio, thrombogenicity index, and hypercholesterolemic FA with increased PUFA content). The lipid, protein, and mineral contents of SPWL were increased while growth performance was maintained on a 1.5% FO-fortified diet. Higher FO levels (3-5%) had a negative impact on the nutritional values and growth performance of the SPWL. Thus, there was a reasonable chance of developing a high-nutrient alternative insect for human consumption.

Indication that starch and sucrose are biomarkers for oil yield in oil palm (Elaeis guineensis Jacq.).

Oil palm (Elaeis guineensis Jacq.) is the most productive oil-producing crop per hectare of land. The oil that accumulates in the mesocarp tissue of the fruit is the highest observed among fruit-producing plants. A comparative analysis between high-, medium-, and low-yielding oil palms, particularly during fruit development, revealed unique characteristics. Metabolomics analysis was able to distinguish accumulation patterns defining of the various developmental stages and oil yield. Interestingly, high- and medium-yielding oil palms exhibited substantially increased sucrose levels compared to low-yielding palms. In addition, parameters such as starch granule morphology, granule size, total starch content, and starch chain length distribution (CLD) differed significantly among the oil yield categories with a clear correlation between oil yield and various starch parameters. These results provide new insights into carbohydrate and starch metabolism for biosynthesis of oil palm fruits, indicating that starch and sucrose can be used as novel, easy-to-analyze, and reliable biomarker for oil yield.

Pro-Oxidant and Cytotoxic Effects of Tucum-Do-Cerrado (Bactris setosa Mart.) Extracts in Colorectal Adenocarcinoma Caco-2 Cells.

Colorectal cancer is one of the most common types of cancer. Bioactive natural compounds can act in cancer chemoprevention as tumor growth inhibitors. Tucum-do-cerrado (Bactris setosa Mart.) is a Brazilian fruit that contains several phenolic compounds. This study investigated the effect of tucum aqueous extract in Caco-2 cells in comparison to primary human intestinal organoids and fibroblasts. Cells were exposed to 0.5 and 1 mg/ml of tucum aqueous extract for 24 h. ROS production, mRNA levels for SOD1 and SOD2, CAT, GPX1, NFE2L2, HIF1A and NOS2 were evaluated in Caco-2 cells exposed to tucum extract. Cell viability of Caco-2 cells was decreased upon tucum extract exposure. Mitochondrial ROS levels increased in Caco-2 cells exposed to tucum extract. The mRNA levels of SOD1, SOD2, CAT, GPX, NFE2L2 and HIF1A were downregulated in Caco-2 cells exposed to tucum extract, while NOS2 mRNA levels remained unchanged. Protein levels of SOD2, CAT and NRF2 remained unchanged in Caco-2 cells treated with tucum extract, indicating that catalase and SOD2 cellular functions may be unaffected by the tucum extract at 24 h, of exposure. Aqueous extract of tucum-do-cerrado may induce cellular toxicity in a cancer cell-specific manner, possibly through increased mitochondrial ROS production and gene expression regulation.

Characterization and functional analysis of the MADS-box EgAGL9 transcription factor from the mesocarp of oil palm (Elaeis guineensis Jacq.).

Oil palm (Elaeis guineensis Jacq.) is one of the most important oil crops in the world, and compared to all oil crops, it has the highest productive efficiency. In the present study, a MADS-box transcription factor of the AGAMOUS class, named EgAGL9, was identified by expression profile analysis in the different developmental stages of oil palm mesocarp. Real-time quantitative PCR results confirmed that the expression of EgAGL9 increased rapidly during the last stages of oil palm mesocarp development. Then, three downstream genes, including EgSAD (Stearoyl-ACP desaturase), EgTSA (Tryptophan synthase) and EgSDH (Succinate dehydrogenase), were screened by ChIP-Seq and data analysis. EMSA analysis verified that EgAGL9 interacted with the promoter regions of EgSAD, EgTSA and EgSDH. Moreover, the expression levels of EgSAD, EgTSA and EgSDH were downregulated in EgAGL9-overexpressing protoplasts and calli of oil palm. Compared to WT, the total lipid content and ratio of unsaturated fatty acids in transgenic calli (including oleic acid, linoleic acid and linolenic acid) were significantly decreased. Together, these results revealed that these three EgAGL9-regulated genes are involved in regulatory pathways in the oil palm mesocarp. Compared with previous studies, the present study provides a new research strategy for understanding of the molecular regulatory pathways of lipid metabolism in mesocarp of oil palm. The obtained results will bring a new perspective for a comprehensive understanding of the regulation of the metabolic accumulation in the oil palm mesocarp.

Laccase production from Bacillus aestuarii KSK using Borassus flabellifer empty fruit bunch waste as a substrate and assessing their malachite green dye degradation.

AIMS: The lignocellulosic waste, Borassus flabellifer empty fruit bunch waste (BFEFBW), was employed to produce laccase using Bacillus aestuarii KSK under solid-state fermentation (SSF) conditions and to assess the efficiency of malachite green (MG) dye decolourization. METHODS AND RESULTS: Abiotic factors such as pH (5.0-9.0), temperature (25-45°C) and incubation time (24-96 h) were optimized using Response surface methodology-Box-Behenan Design (RSM-BBD) to exploit the laccase production. The anticipated model revealed that the highest laccase activity of 437 U/ml shows after 60 h of incubation at 35°C at pH 7.0. The bacterial laccase was used to remove 89% of the MG dye in less time. CONCLUSION: The laccase from B. aestuarii KSK decolorizes the MG and thereby making it a suitable choice for wastewater treatment from industrial effluents. SIGNIFICANCE AND IMPACT OF THE STUDY: This study is the first report on the production of laccase from B. flabellifer empty fruit bunch waste as a substrate. Bacillus aestuarii KSK was isolated from the soil sample and used to produce laccase under SSF conditions. The bacterial laccase has the potential for industrial application in textile waste dye treatment.

EgMYB108 regulates very long-chain fatty acid (VLCFA) anabolism in the mesocarp of oil palm.

KEY MESSAGE: EgMYB108 regulates VLCFA anabolism in oil palm. Very long-chain fatty acids (VLCFAs), which are fatty acids with more than 18 C, can not only be used as a form of triglyceride (TAG) but also provide precursors for the biosynthesis of cuticle wax, and they exist in plant epidermal cells in the form of wax in higher plants. However, which and how transcriptional factors (TFs) regulate this process is largely unknown in oil palm. In this study, a MYB transcription factor (EgMYB108) with high expression in the mesocarp of oil palm fruit was characterized. Overexpression of EgMYB108 promoted not only total lipid content but also VLCFA accumulation in oil palm embryoids. Subsequently, transient transformation in protoplasts and qRT-PCR analysis indicated that the EgKCS5 and EgLACS4 genes were significantly increased with the overexpression of EgMYB108. Furthermore, yeast one­hybrid assays, dual-luciferase assays and EMSAs demonstrated that EgMYB108 binds to the promoters of EgKCS5 and EgLACS4 and regulates their transcription. Finally, EgMYB108 interacts with the promoters of EgLACS and EgKCS simultaneously and finally improves the VLCFA and total lipid contents; a pathway summarizing this interaction was depicted.. The results provide new insight into the mechanism by which EgMYB108 regulates lipid and VLCFA accumulation in oil palm.

Defense response changes in roots of oil palm (Elaeis guineensis Jacq.) seedlings after internal symptoms of Ganoderma boninense Pat. infection.

BACKGROUND: The development of basal stem rot (BSR) disease in oil palm is associated with lignin during vegetative growth and salicylic acid (SA) biosynthesis. The increase in the lignin content, SA accumulation, growth, and root biomass could indicate the resistance of oil palm seedlings to BSR disease. Therefore, although there are many studies on the interactions between the Ganoderma boninense and oil palm, research on evaluation of physiological processes, biochemistry, and molecules occurring during early internal symptoms of BSR in roots of oil palm (Elaeis guineensis Jacq.) are essential. RESULTS: Ganoderma boninense inoculation indicated that C01, C02, and C05 seedlings were susceptible, while the other three seedlings, C03, C07, and C08, were resistant based on Ganoderma Disease Index (GDI). Infection by G. boninense in the most susceptible seedlings C05 reduced fresh weight of roots (FW) by 9.0%, and lignin content by 10.9%. The most resistant seedlings C08 were reduced by only 8.4%, and 0.2% regarding their fresh weight and lignin content, respectively. BSR disease induced SA accumulation in the most susceptible C08 and decreased peroxidase (PRX) enzyme (EC 1.11.1.7) activities in root tissues of oil palm seedlings except C07 and C08 where PRX activities remained high in the 4 months after planting. Infection with G. boninense also increased glutathione S-transferase U19-like (EgGSTU19) gene expression in the root tissues of susceptible seedlings, while laccase-24 (EgLCC24) gene expression was associated with resistance against BSR disease. Based on the relative expression of twelve genes, two genes are categorized as receptors (EgWAKL5, EgMIK1), two genes as biosynthesis signal transduction compound (EgOPR5, EgACO1), five genes as defense responses (EgROMT, EgSOT12, EgLCC24, EgGLT3, EgGSTU19), and one gene as trans-resveratrol di-O-methyltransferase-like (EgRNaseIII) predicted related to BSR infection. While two other genes remain unknown (EgUnk1, EgUnk2). CONCLUSIONS: Ganoderma infection-induced SA accumulation and lignification in resistant accessions promote the seedlings root biomass. Oil palm seedlings have a synergistic physical, biochemical, and molecular defense mechanism to the BSR disease. The utilization of nucleotide-based molecular markers using EgLCC24 gene is able to detect resistant oil palm seedlings to G. boninense.