Displaying publications 1 - 20 of 25 in total

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  1. Omidvar V, Abdullah SN, Izadfard A, Ho CL, Mahmood M
    Planta, 2010 Sep;232(4):925-36.
    PMID: 20635097 DOI: 10.1007/s00425-010-1220-z
    The 1,053-bp promoter of the oil palm metallothionein gene (so-called MSP1) and its 5' deletions were fused to the GUS reporter gene, and analysed in transiently transformed oil palm tissues. The full length promoter showed sevenfold higher activity in the mesocarp than in leaves and 1.5-fold more activity than the CaMV35S promoter in the mesocarp. The 1,053-bp region containing the 5' untranslated region (UTR) gave the highest activity in the mesocarp, while the 148-bp region was required for minimal promoter activity. Two positive regulatory regions were identified at nucleotides (nt) -953 to -619 and -420 to -256 regions. Fine-tune deletion of the -619 to -420 nt region led to the identification of a 21-bp negative regulatory sequence in the -598 to -577 nt region, which is involved in mesocarp-specific expression. Gel mobility shift assay revealed a strong interaction of the leaf nuclear extract with the 21-bp region. An AGTTAGG core-sequence within this region was identified as a novel negative regulatory element controlling fruit-specificity of the MSP1 promoter. Abscisic acid (ABA) and copper (Cu(2+)) induced the activity of the promoter and its 5' deletions more effectively than methyl jasmonate (MeJa) and ethylene. In the mesocarp, the full length promoter showed stronger inducibility in response to ABA and Cu(2+) than its 5' deletions, while in leaves, the -420 nt fragment was the most inducible by ABA and Cu(2+). These results suggest that the MSP1 promoter and its regulatory regions are potentially useful for engineering fruit-specific and inducible gene expression in oil palm.
    Matched MeSH terms: Fruit/genetics*
  2. Ong-Abdullah M, Ordway JM, Jiang N, Ooi SE, Kok SY, Sarpan N, et al.
    Nature, 2015 Sep 24;525(7570):533-7.
    PMID: 26352475 DOI: 10.1038/nature15365
    Somaclonal variation arises in plants and animals when differentiated somatic cells are induced into a pluripotent state, but the resulting clones differ from each other and from their parents. In agriculture, somaclonal variation has hindered the micropropagation of elite hybrids and genetically modified crops, but the mechanism responsible remains unknown. The oil palm fruit 'mantled' abnormality is a somaclonal variant arising from tissue culture that drastically reduces yield, and has largely halted efforts to clone elite hybrids for oil production. Widely regarded as an epigenetic phenomenon, 'mantling' has defied explanation, but here we identify the MANTLED locus using epigenome-wide association studies of the African oil palm Elaeis guineensis. DNA hypomethylation of a LINE retrotransposon related to rice Karma, in the intron of the homeotic gene DEFICIENS, is common to all mantled clones and is associated with alternative splicing and premature termination. Dense methylation near the Karma splice site (termed the Good Karma epiallele) predicts normal fruit set, whereas hypomethylation (the Bad Karma epiallele) predicts homeotic transformation, parthenocarpy and marked loss of yield. Loss of Karma methylation and of small RNA in tissue culture contributes to the origin of mantled, while restoration in spontaneous revertants accounts for non-Mendelian inheritance. The ability to predict and cull mantling at the plantlet stage will facilitate the introduction of higher performing clones and optimize environmentally sensitive land resources.
    Matched MeSH terms: Fruit/genetics
  3. Lawson T, Lycett GW, Mayes S, Ho WK, Chin CF
    Mol Biol Rep, 2020 Jun;47(6):4183-4197.
    PMID: 32444976 DOI: 10.1007/s11033-020-05519-y
    The Rab GTPase family plays a vital role in several plant physiological processes including fruit ripening. Fruit softening during ripening involves trafficking of cell wall polymers and enzymes between cellular compartments. Mango, an economically important fruit crop, is known for its delicious taste, exotic flavour and nutritional value. So far, there is a paucity of information on the mango Rab GTPase family. In this study, 23 genes encoding Rab proteins were identified in mango by a comprehensive in silico approach. Sequence alignment and similarity tree analysis with the model plant Arabidopsis as a reference enabled the bona fide assignment of the deduced mango proteins to classify into eight subfamilies. Expression analysis by RNA-Sequencing (RNA-Seq) showed that the Rab genes were differentially expressed in ripe and unripe mangoes suggesting the involvement of vesicle trafficking during ripening. Interaction analysis showed that the proteins involved in vesicle trafficking and cell wall softening were interconnected providing further evidence of the involvement of the Rab GTPases in fruit softening. Correlation analyses showed a significant relationship between the expression level of the RabA3 and RabA4 genes and fruit firmness at the unripe stage of the mango varieties suggesting that the differences in gene expression level might be associated with the contrasting firmness of these varieties. This study will not only provide new insights into the complexity of the ripening-regulated molecular mechanism but also facilitate the identification of potential Rab GTPases to address excessive fruit softening.
    Matched MeSH terms: Fruit/genetics
  4. Teh BT, Lim K, Yong CH, Ng CCY, Rao SR, Rajasegaran V, et al.
    Nat Genet, 2017 Nov;49(11):1633-1641.
    PMID: 28991254 DOI: 10.1038/ng.3972
    Durian (Durio zibethinus) is a Southeast Asian tropical plant known for its hefty, spine-covered fruit and sulfury and onion-like odor. Here we present a draft genome assembly of D. zibethinus, representing the third plant genus in the Malvales order and first in the Helicteroideae subfamily to be sequenced. Single-molecule sequencing and chromosome contact maps enabled assembly of the highly heterozygous durian genome at chromosome-scale resolution. Transcriptomic analysis showed upregulation of sulfur-, ethylene-, and lipid-related pathways in durian fruits. We observed paleopolyploidization events shared by durian and cotton and durian-specific gene expansions in MGL (methionine γ-lyase), associated with production of volatile sulfur compounds (VSCs). MGL and the ethylene-related gene ACS (aminocyclopropane-1-carboxylic acid synthase) were upregulated in fruits concomitantly with their downstream metabolites (VSCs and ethylene), suggesting a potential association between ethylene biosynthesis and methionine regeneration via the Yang cycle. The durian genome provides a resource for tropical fruit biology and agronomy.
    Matched MeSH terms: Fruit/genetics*
  5. Saed Taha R, Ismail I, Zainal Z, Abdullah SN
    J Plant Physiol, 2012 Sep 01;169(13):1290-300.
    PMID: 22658816 DOI: 10.1016/j.jplph.2012.05.001
    The stearoyl-acyl-carrier-protein (ACP) desaturase is a plastid-localized enzyme that catalyzes the conversion of stearoyl-ACP to oleoyl-ACP and plays an important role in the determination of the properties of the majority of cellular glycerolipids. Functional characterization of the fatty acid desaturase genes and their specific promoters is a prerequisite for altering the composition of unsaturated fatty acids of palm oil by genetic engineering. In this paper, the specificity and strength of the oil palm stearoyl-ACP desaturase gene promoter (Des) was evaluated in transgenic tomato plants. Transcriptional fusions between 5' deletions of the Des promoter (Des1-4) and the β-glucuronidase (GUS) reporter gene were generated and their expression analyzed in different tissues of stably transformed tomato plants. Histochemical analysis of the Des promoter deletion series revealed that GUS gene expression was confined to the tomato fruits. No expression was detected in vegetative tissues of the transgenic plants. The highest levels of GUS activity was observed in different tissues of ripe red fruits (vascular tissue, septa, endocarp, mesocarp and columella) and in seeds, which harbored the promoter region located between -590 and +10. A comparison of the promoter-deletion constructs showed that the Des4 promoter deletion (314bp) produced a markedly low level of GUS expression in fruits and seeds. Fluorometric analysis of the GUS activity revealed a 4-fold increase in the activity of the full-length Des promoter compared to the CaMV35S promoter. RNA-hybridization analyses provided additional evidence of increased GUS expression in fruits driven by a Des fragment. Taken together, these results demonstrate the potential of the Des promoter as a tool for the genetic engineering of oil palms and other species, including dicots, in improving the quality and nutritional value of the fruits.
    Matched MeSH terms: Fruit/genetics
  6. Singh R, Low ET, Ooi LC, Ong-Abdullah M, Nookiah R, Ting NC, et al.
    Nat Commun, 2014 Jun 30;5:4106.
    PMID: 24978855 DOI: 10.1038/ncomms5106
    Oil palm, a plantation crop of major economic importance in Southeast Asia, is the predominant source of edible oil worldwide. We report the identification of the virescens (VIR) gene, which controls fruit exocarp colour and is an indicator of ripeness. VIR is a R2R3-MYB transcription factor with homology to Lilium LhMYB12 and similarity to Arabidopsis production of anthocyanin pigment1 (PAP1). We identify five independent mutant alleles of VIR in over 400 accessions from sub-Saharan Africa that account for the dominant-negative virescens phenotype. Each mutation results in premature termination of the carboxy-terminal domain of VIR, resembling McClintock's C1-I allele in maize. The abundance of alleles likely reflects cultural practices, by which fruits were venerated for magical and medicinal properties. The identification of VIR will allow selection of the trait at the seed or early-nursery stage, 3-6 years before fruits are produced, greatly advancing introgression into elite breeding material.
    Matched MeSH terms: Fruit/genetics
  7. Ong WD, Voo CL, Kumar SV
    Mol Biol Rep, 2012 May;39(5):5889-96.
    PMID: 22207174 DOI: 10.1007/s11033-011-1400-3
    Improving the quality of the non-climacteric fruit, pineapple, is possible with information on the expression of genes that occur during the process of fruit ripening. This can be made known though the generation of partial mRNA transcript sequences known as expressed sequence tags (ESTs). ESTs are useful not only for gene discovery but also function as a resource for the identification of molecular markers, such as simple sequence repeats (SSRs). This paper reports on firstly, the construction of a normalized library of the mature green pineapple fruit and secondly, the mining of EST-SSRs markers using the newly obtained pineapple ESTs as well as publically available pineapple ESTs deposited in GenBank. Sequencing of the clones from the EST library resulted in 282 good sequences. Assembly of sequences generated 168 unique transcripts (UTs) consisting of 34 contigs and 134 singletons with an average length of ≈500 bp. Annotation of the UTs categorized the known proteins transcripts into the three ontologies as: molecular function (34.88%), biological process (38.43%), and cellular component (26.69%). Approximately 7% (416) of the pineapple ESTs contained SSRs with an abundance of trinucleotide SSRs (48.3%) being identified. This was followed by dinucleotide and tetranucleotide SSRs with frequency of 46 and 57%, respectively. From these EST-containing SSRs, 355 (85.3%) matched to known proteins while 133 contained flanking regions for primer design. Both the ESTs were sequenced and the mined EST-SSRs will be useful in the understanding of non-climacteric ripening and the screening of biomarkers linked to fruit quality traits.
    Matched MeSH terms: Fruit/genetics
  8. Chew BL, Fisk ID, Fray R, Tucker GA, Bodi Z, Ferguson A, et al.
    Plant Cell Rep, 2017 Jan;36(1):81-87.
    PMID: 27662835 DOI: 10.1007/s00299-016-2058-z
    KEY MESSAGE: This study highlights the changes in umami-related nucleotide and glutamate levels when the AMP deaminase gene was elevated in transgenic tomato. Taste is perceived as one of a combination of five sensations, sweet, sour, bitter, salty, and umami. The umami taste is best known as a savoury sensation and plays a central role in food flavour, palatability, and eating satisfaction. Umami flavour can be imparted by the presence of glutamate and is greatly enhanced by the addition of ribonucleotides, such as inosine monophosphate (IMP) and guanosine monophosphate (GMP). The production of IMP is regulated by the enzyme adenosine monophosphate (AMP) deaminase which functions to convert AMP into IMP. We have generated transgenic tomato (Solanum lycopersicum) lines over expressing AMP deaminase under the control of a fruit-specific promoter. The transgenic lines showed substantially enhanced levels of AMP deaminase expression in comparison to the wild-type control. Elevated AMP deaminase levels resulted in the reduced accumulation of glutamate and increased levels of the umami nucleotide GMP. AMP concentrations were unchanged. The effects on the levels of glutamate and GMP were unexpected and are discussed in relation to the metabolite flux within this pathway.
    Matched MeSH terms: Fruit/genetics
  9. Cherian S, Figueroa CR, Nair H
    J Exp Bot, 2014 Sep;65(17):4705-22.
    PMID: 24994760 DOI: 10.1093/jxb/eru280
    Fruit ripening is a complex and highly coordinated developmental process involving the expression of many ripening-related genes under the control of a network of signalling pathways. The hormonal control of climacteric fruit ripening, especially ethylene perception and signalling transduction in tomato has been well characterized. Additionally, great strides have been made in understanding some of the major regulatory switches (transcription factors such as RIPENING-INHIBITOR and other transcriptional regulators such as COLOURLESS NON-RIPENING, TOMATO AGAMOUS-LIKE1 and ETHYLENE RESPONSE FACTORs), that are involved in tomato fruit ripening. In contrast, the regulatory network related to non-climacteric fruit ripening remains poorly understood. However, some of the most recent breakthrough research data have provided several lines of evidences for abscisic acid- and sucrose-mediated ripening of strawberry, a non-climacteric fruit model. In this review, we discuss the most recent research findings concerning the hormonal regulation of fleshy fruit ripening and their cross-talk and the future challenges taking tomato as a climacteric fruit model and strawberry as a non-climacteric fruit model. We also highlight the possible contribution of epigenetic changes including the role of plant microRNAs, which is opening new avenues and great possibilities in the fields of fruit-ripening research and postharvest biology.
    Matched MeSH terms: Fruit/genetics
  10. Yeap WC, Lee FC, Shabari Shan DK, Musa H, Appleton DR, Kulaveerasingam H
    Plant J, 2017 Jul;91(1):97-113.
    PMID: 28370622 DOI: 10.1111/tpj.13549
    The oil biosynthesis pathway must be tightly controlled to maximize oil yield. Oil palm accumulates exceptionally high oil content in its mesocarp, suggesting the existence of a unique fruit-specific fatty acid metabolism transcriptional network. We report the complex fruit-specific network of transcription factors responsible for modulation of oil biosynthesis genes in oil palm mesocarp. Transcriptional activation of EgWRI1-1 encoding a key master regulator that activates expression of oil biosynthesis genes, is activated by three ABA-responsive transcription factors, EgNF-YA3, EgNF-YC2 and EgABI5. Overexpression of EgWRI1-1 and its activators in Arabidopsis accelerated flowering, increased seed size and oil content, and altered expression levels of oil biosynthesis genes. Protein-protein interaction experiments demonstrated that EgNF-YA3 interacts directly with EgWRI1-1, forming a transcription complex with EgNF-YC2 and EgABI5 to modulate transcription of oil biosynthesis pathway genes. Furthermore, EgABI5 acts downstream of EgWRKY40, a repressor that interacts with EgWRKY2 to inhibit the transcription of oil biosynthesis genes. We showed that expression of these activators and repressors in oil biosynthesis can be induced by phytohormones coordinating fruit development in oil palm. We propose a model highlighting a hormone signaling network coordinating fruit development and fatty acid biosynthesis.
    Matched MeSH terms: Fruit/genetics
  11. Sekeli R, Abdullah JO, Namasivayam P, Muda P, Abu Bakar UK, Yeong WC, et al.
    Molecules, 2014 Jun 19;19(6):8350-62.
    PMID: 24950439 DOI: 10.3390/molecules19068350
    The purpose of this study was to evaluate the effectiveness of using RNA interference in down regulating the expression of 1-aminocyclopropane-1-carboxylic acid oxidase gene in Eksotika papaya. One-month old embryogenic calli were separately transformed with Agrobacterium strain LBA 4404 harbouring the three different RNAi pOpOff2 constructs bearing the 1-aminocyclopropane-1-carboxylic acid oxidase gene. A total of 176 putative transformed lines were produced from 15,000 calli transformed, selected, then regenerated on medium supplemented with kanamycin. Integration and expression of the targeted gene in putatively transformed lines were verified by PCR and real-time RT-PCR. Confined field evaluation of a total of 31 putative transgenic lines planted showed a knockdown expression of the targeted ACO1 and ACO2 genes in 13 lines, which required more than 8 days to achieve the full yellow colour (Index 6). Fruits harvested from lines pRNAiACO2 L2-9 and pRNAiACO1 L2 exhibited about 20 and 14 days extended post-harvest shelf life to reach Index 6, respectively. The total soluble solids contents of the fruits ranged from 11 to 14° Brix, a range similar to fruits from non-transformed, wild type seed-derived plants.
    Matched MeSH terms: Fruit/genetics
  12. Intan Sakinah MA, Suzianti IV, Latiffah Z
    Genet. Mol. Res., 2014;13(2):3627-37.
    PMID: 24854442 DOI: 10.4238/2014.May.9.5
    Anthracnose caused by Colletotrichum species is a common postharvest disease of banana fruit. We investigated and identified Colletotrichum species associated with anthracnose in several local banana cultivars based on morphological characteristics and sequencing of ITS regions and of the β-tubulin gene. Thirty-eight Colletotrichum isolates were encountered in anthracnose lesions of five local banana cultivars, 'berangan', 'mas', 'awak', 'rastali', and 'nangka'. Based on morphological characteristics, 32 isolates were identified as Colletotrichum gloeosporioides and 6 isolates as C. musae. C. gloeosporioides isolates were divided into two morphotypes, with differences in colony color, shape of the conidia and growth rate. Based on ITS regions and β-tubulin sequences, 35 of the isolates were identified as C. gloeosporioides and only 3 isolates as C. musae; the percentage of similarity from BLAST ranged from 95-100% for ITS regions and 97-100% for β-tubulin. C. gloeosporioides isolates were more prevalent compared to C. musae. This is the first record of C. gloeosporioides associated with banana anthracnose in Malaysia. In a phylogenetic analysis of the combined dataset of ITS regions and β-tubulin using a maximum likelihood method, C. gloeosporioides and C. musae isolates were clearly separated into two groups. We concluded that C. gloeosporioides and C. musae isolates are associated with anthracnose in the local banana cultivars and that C. gloeosporioides is more prevalent than C. musae.
    Matched MeSH terms: Fruit/genetics
  13. Bahari M, Rafii MY, Saleh GB, Latif MA
    ScientificWorldJournal, 2012;2012:543158.
    PMID: 22566772 DOI: 10.1100/2012/543158
    The experiments were carried out in two research stations (MARDI Bukit Tangga, Kedah, and MARDI Seberang Perai, Penang) in Malaysia. The crossings were performed using the four inbred lines in complete diallel cross including selfs and reciprocals. We evaluated the yield components and fruit characters such as fruit yield per plant, vine length, days to fruit maturity, fruit weight, total soluble solid content, and rind thickness over a period of two planting seasons. General combining ability and its interaction with locations were statistically significant for all characteristics except number of fruits per plant across the environments. Results indicated that the additive genetic effects were important to the inheritance of these traits and the expression of additive genes was influenced greatly by environments. In addition, specific combining ability effect was statistically evident for fruit yield per plant, vine length, days to first female flower, and fruit weight. Most of the characters are simultaneously controlled by additive and nonadditive gene effects. This study demonstrated that the highest potential and promising among the crosses was cross P2 (BL-14) × P3 (6372-4), which possessed prolific plants, with early maturity, medium fruit weight and high soluble solid contents. Therefore this hybrid might be utilized for developing high yielding watermelon cultivars and may be recommended for commercial cultivation.
    Matched MeSH terms: Fruit/genetics
  14. Ong WD, Voo LY, Kumar VS
    PLoS One, 2012;7(10):e46937.
    PMID: 23091603 DOI: 10.1371/journal.pone.0046937
    BACKGROUND: Pineapple (Ananas comosus var. comosus), is an important tropical non-climacteric fruit with high commercial potential. Understanding the mechanism and processes underlying fruit ripening would enable scientists to enhance the improvement of quality traits such as, flavor, texture, appearance and fruit sweetness. Although, the pineapple is an important fruit, there is insufficient transcriptomic or genomic information that is available in public databases. Application of high throughput transcriptome sequencing to profile the pineapple fruit transcripts is therefore needed.

    METHODOLOGY/PRINCIPAL FINDINGS: To facilitate this, we have performed transcriptome sequencing of ripe yellow pineapple fruit flesh using Illumina technology. About 4.7 millions Illumina paired-end reads were generated and assembled using the Velvet de novo assembler. The assembly produced 28,728 unique transcripts with a mean length of approximately 200 bp. Sequence similarity search against non-redundant NCBI database identified a total of 16,932 unique transcripts (58.93%) with significant hits. Out of these, 15,507 unique transcripts were assigned to gene ontology terms. Functional annotation against Kyoto Encyclopedia of Genes and Genomes pathway database identified 13,598 unique transcripts (47.33%) which were mapped to 126 pathways. The assembly revealed many transcripts that were previously unknown.

    CONCLUSIONS: The unique transcripts derived from this work have rapidly increased of the number of the pineapple fruit mRNA transcripts as it is now available in public databases. This information can be further utilized in gene expression, genomics and other functional genomics studies in pineapple.

    Matched MeSH terms: Fruit/genetics*
  15. Deng S, Mai Y, Niu J
    Gene, 2019 Mar 20;689:131-140.
    PMID: 30576805 DOI: 10.1016/j.gene.2018.12.016
    Citrus maxima "seedless" is originally from Malaysia, and now is widely cultivated in Hainan province, China. The essential features of this cultivar are thin skin, green epicarp and seedless at the ripening stage. Here, using C. maxima "seedless" as experimental material, we investigated the physical and inclusion indicators, and found the accumulation of storage compounds during 120-210 DAF leading to inconsistent increase between volume and weight. Component analysis of soluble sugar indicated that arabinose and xylose have a high content in early development of pummelo juice sacs (PJS), whereas fructose, glucose and sucrose show a significant increase during PJS maturation. To clarify a global overview of the gene expressing profiles, the PJSs from four periods (60, 120, 180 and 240 DAF) were selected for comparative transcriptome analysis. The resulting 8275 unigenes showed differential expression during PJS development. Also, the stability of 11 housekeeping genes were evaluated by geNorm method, resulting in a set of five genes (UBC, ACT, OR23, DWA2 and CYP21D) used as control for normalization of gene expression. Based on transcriptome data, 5 sucrose synthases (SUSs) and 10 invertases (INVs) were identified to be involved in sucrose degradation. Importantly, SUS4 may be responsible for arabinose and xylose biosynthesis to form the cell wall in early development, while SUS3 and VIN2 may be important in the accumulation of soluble hexose leading to cell expansion through an osmotic-independent pathway in late development. The information provides valuable metabolite and genetic resources in C. maxima "seedless", and is important for achieving high fruit yield and quality.
    Matched MeSH terms: Fruit/genetics
  16. Ridzuan R, Rafii MY, Mohammad Yusoff M, Ismail SI, Miah G, Usman M
    J Sci Food Agric, 2019 Jan 15;99(1):269-280.
    PMID: 29851100 DOI: 10.1002/jsfa.9169
    BACKGROUND: Assessment of the different desirable characters among chili genotypes has expanded the effective selection for crop improvement. Identification of genetically superior parents is important in assortment of the best parents to develop new chili hybrids.

    RESULTS: This study was done to assess the hereditary assorted variety of selected genotypes of Capsicum annuum based on their morphophysiological and yield traits in two planting seasons. The biochemical properties, capsaicinoid content (capsaicin and dihydrocapsaicin), total phenolics content and antioxidant action determination of unripe and ripe chili pepper fruits were carried out in dry fruits. AVPP9813 and Kulai 907 were observed to have high fruit yields, with 541.39 and 502.64 g per plant, respectively. The most increased genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) were shown by the fruit number per plant (49.71% and 66.04%, respectively). High heritability was observed in yield characters viz-à-viz fruit weight, length and girth and indicated high genetic advance. Eight groups were obtained from the cluster analysis. For the biochemical analysis, the capsaicinoid content and total phenolic content were high in Chili Bangi 3 at unripe and ripe fruit stages, while for antioxidant activity SDP203 was the highest in ripe dry fruit.

    CONCLUSION: Higher GCV and PCV, combined with moderate to high heritability and high hereditary progress, were seen in number of fruit per plant, fruit yield per plant and fruit weight per fruit. These findings are beneficial for chili pepper breeders to select desirable quantitative characters in C. annuum in their breeding program. © 2018 Society of Chemical Industry.

    Matched MeSH terms: Fruit/genetics
  17. Wong YC, Teh HF, Mebus K, Ooi TEK, Kwong QB, Koo KL, et al.
    BMC Genomics, 2017 06 21;18(1):470.
    PMID: 28637447 DOI: 10.1186/s12864-017-3855-7
    BACKGROUND: The oil yield trait of oil palm is expected to involve multiple genes, environmental influences and interactions. Many of the underlying mechanisms that contribute to oil yield are still poorly understood. In this study, we used a microarray approach to study the gene expression profiles of mesocarp tissue at different developmental stages, comparing genetically related high- and low- oil yielding palms to identify genes that contributed to the higher oil-yielding palm and might contribute to the wider genetic improvement of oil palm breeding populations.

    RESULTS: A total of 3412 (2001 annotated) gene candidates were found to be significantly differentially expressed between high- and low-yielding palms at at least one of the different stages of mesocarp development evaluated. Gene Ontologies (GO) enrichment analysis identified 28 significantly enriched GO terms, including regulation of transcription, fatty acid biosynthesis and metabolic processes. These differentially expressed genes comprise several transcription factors, such as, bHLH, Dof zinc finger proteins and MADS box proteins. Several genes involved in glycolysis, TCA, and fatty acid biosynthesis pathways were also found up-regulated in high-yielding oil palm, among them; pyruvate dehydrogenase E1 component Subunit Beta (PDH), ATP-citrate lyase, β- ketoacyl-ACP synthases I (KAS I), β- ketoacyl-ACP synthases III (KAS III) and ketoacyl-ACP reductase (KAR). Sucrose metabolism-related genes such as Invertase, Sucrose Synthase 2 and Sucrose Phosphatase 2 were found to be down-regulated in high-yielding oil palms, compared to the lower yield palms.

    CONCLUSIONS: Our findings indicate that a higher carbon flux (channeled through down-regulation of the Sucrose Synthase 2 pathway) was being utilized by up-regulated genes involved in glycolysis, TCA and fatty acid biosynthesis leading to enhanced oil production in the high-yielding oil palm. These findings are an important stepping stone to understand the processes that lead to production of high-yielding oil palms and have implications for breeding to maximize oil production.

    Matched MeSH terms: Fruit/genetics*
  18. Lithanatudom SK, Chaowasku T, Nantarat N, Jaroenkit T, Smith DR, Lithanatudom P
    Sci Rep, 2017 07 27;7(1):6716.
    PMID: 28751754 DOI: 10.1038/s41598-017-07045-7
    Dimocarpus longan, commonly known as the longan, belongs to the family Sapindaceae, and is one of the most economically important fruits commonly cultivated in several regions in Asia. There are various cultivars of longan throughout the Thai-Malay peninsula region, but until now no phylogenetic analysis has been undertaken to determine the genetic relatedness of these cultivars. To address this issue, 6 loci, namely ITS2, matK, rbcL, trnH-psbA, trnL-I and trnL-trnF were amplified and sequenced from 40 individuals consisting of 26 longan cultivars 2 types of lychee and 8 herbarium samples. The sequencing results were used to construct a phylogenetic tree using the neighbor-joining (NJ), maximum likelihood (ML) and Bayesian inference (BI) criteria. The tree showed cryptic groups of D. longan from the Thailand-Malaysia region (Dimocarpus longan spp.). This is the first report of the genetic relationship of Dimocarpus based on multi-locus molecular markers and morphological characteristics. Multiple sequence alignments, phylogenetic trees and species delimitation support that Dimocarpus longan spp. longan var. obtusus and Dimocarpus longan spp. malesianus var. malesianus should be placed into a higher order and are two additional species in the genus Dimocarpus. Therefore these two species require nomenclatural changes as Dimocarpus malesianus and Dimocarpus obtusus, respectively.
    Matched MeSH terms: Fruit/genetics*
  19. Usman MG, Rafii MY, Ismail MR, Malek MA, Abdul Latif M
    ScientificWorldJournal, 2014;2014:308042.
    PMID: 25478590 DOI: 10.1155/2014/308042
    High temperature tolerance is an important component of adaptation to arid and semiarid cropping environment in chili pepper. Two experiments were carried out to study the genetic variability among chili pepper for heat tolerance and morphophysiological traits and to estimate heritability and genetic advance expected from selection. There was a highly significant variation among the genotypes in response to high temperature (CMT), photosynthesis rate, plant height, disease incidence, fruit length, fruit weight, number of fruits, and yield per plant. At 5% selection intensity, high genetic advance as percent of the mean (>20%) was observed for CMT, photosynthesis rate, fruit length, fruit weight, number of fruits, and yield per plant. Similarly, high heritability (>60%) was also observed indicating the substantial effect of additive gene more than the environmental effect. Yield per plant showed strong to moderately positive correlations (r = 0.23-0.56) at phenotypic level while at genotypic level correlation coefficient ranged from 0.16 to 0.72 for CMT, plant height, fruit length, and number of fruits. Cluster analysis revealed eight groups and Group VIII recorded the highest CMT and yield. Group IV recorded 13 genotypes while Groups II, VII, and VIII recorded one each. The results showed that the availability of genetic variance could be useful for exploitation through selection for further breeding purposes.
    Matched MeSH terms: Fruit/genetics*
  20. Teh CK, Muaz SD, Tangaya P, Fong PY, Ong AL, Mayes S, et al.
    Sci Rep, 2017 06 08;7(1):3118.
    PMID: 28596562 DOI: 10.1038/s41598-017-03225-7
    The fundamental trait in selective breeding of oil palm (Eleais guineensis Jacq.) is the shell thickness surrounding the kernel. The monogenic shell thickness is inversely correlated to mesocarp thickness, where the crude palm oil accumulates. Commercial thin-shelled tenera derived from thick-shelled dura × shell-less pisifera generally contain 30% higher oil per bunch. Two mutations, sh MPOB (M1) and sh AVROS (M2) in the SHELL gene - a type II MADS-box transcription factor mainly present in AVROS and Nigerian origins, were reported to be responsible for different fruit forms. In this study, we have tested 1,339 samples maintained in Sime Darby Plantation using both mutations. Five genotype-phenotype discrepancies and eight controls were then re-tested with all five reported mutations (sh AVROS , sh MPOB , sh MPOB2 , sh MPOB3 and sh MPOB4 ) within the same gene. The integration of genotypic data, pedigree records and shell formation model further explained the haploinsufficiency effect on the SHELL gene with different number of functional copies. Some rare mutations were also identified, suggesting a need to further confirm the existence of cis-compound mutations in the gene. With this, the prediction accuracy of fruit forms can be further improved, especially in introgressive hybrids of oil palm. Understanding causative variant segregation is extremely important, even for monogenic traits such as shell thickness in oil palm.
    Matched MeSH terms: Fruit/genetics*
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