Judul: Transcriptomic Analysis of Oil-Producing Leaves from Dryobalanops aromatica and Dryobalanops lanceolata
Abstrak: Dryobalanops aromatica dan Dryobalanops lanceolata dikelompokkan menjadi pohon serbaguna penghasil hasil hutan bukan kayu (HHBK) seperti damar dari batang dan minyak dari daunnya. Pengetahuan tentang mekanisme produksi minyak pada daun D. aromatica dan D. lanceolata pada tingkat molekuler masih terbatas sehingga dapat bermanfaat untuk penelitian genomik dan transkriptomik lebih lanjut. Penelitian ini dilakukan untuk menganalisis transkriptomik dan mengidentifikasi ekspresi gen yang terlibat dalam produksi minyak kamper berdasarkan RNA Sequencing (RNA-seq). Analisis transkriptome dilakukan dengan RNA-seq, pemeriksaan kualitas reads, de novo assembly, dan functional annotation. Hasil penelitian menunjukkan bahwa total clean reads mencapai 26,4 juta untuk D. aromatica dan 26,9 juta untuk daun D. lanceolata. Assembler trinity menghasilkan jumlah contigs sebesar 98.369 untuk D. aromatica dan 108.009 contigs dari D. lanceolata. Berdasarkan analisis gene ontology dari kategori fungsi molekular, komponen selular dan proses biologis secara berturut-turut didominasi gen yang berperan dalam pengikatan protein, komponen integral membran, dan transpor transmembran terekspresikan lebih tinggi dibandingkan dengan gen lain yang teridentifikasi. Faktor transkripsi monotorpen pada hasil anotasi yang ditemukan antara lain: AP2/ERF, bHLH, bZIP, MYB, dan WRKY.
Keyword: Dryobalanops aromatica, Dryobalanops lanceolata, minyak daun, transkriptom

Judul: Trancriptomic Analysis of Kamper (Dryobalanops aromatica) Grown in Peat Media and Mineral Soil
Abstrak: Dryobalanops aromatica is a highly economic value resin-producing tree. It has been known as an essential international trade commodity widely used in the perfume, cosmetics, medicine, and wood industries. In natural habitats, this adaptive species has been found to grow well on peatland and mineral soils. The information regarding adaptive genes in Indonesian native trees to abiotic stress is still very limited. The research was conducted to analyse the differential gene expression (DGEs) that can elucidate the role of several up-regulated and down-regulated genes under peat media and mineral soil treatments. DGE analysis was carried out using R software, Bioconductor package 'edgeR'. Using the Benjamini and Hochberg approach to control FDR (false discovery rate) with the value of FDR is 0.05), with a log2FC (log2 fold change) with minimal value 2 and p-value of 0.05, showed 320 contigs were up-regulated, and 439 contigs were down-regulated, while 58129 contigs were not significantly expressed. Furthermore, this study also presents an overview of the genes involved in different pathways, such as photosynthesis, carbon and energy metabolism, phytohormone-related genes, nitrogen metabolism, reactive oxygen species, and transcription factor. This information will be helpful in understanding D. aromatica molecular responses to stress conditions that may be useful for selecting genotypes in the breeding programs or peatlands restoration. We found that genes involved in plant stress phytohormone biosynthesis, such as JA (jasmonic acid), ET (ethylene), GB (gibberellic acid), were up-regulated. In contrast, genes involved in ABA and IAA showed down-regulated on peat media treatment. Further, genes encode biological functions of the cell wall, and molecular functions as metal ion binding were up-regulated. Genes that function as antibiotics and ROS scavengers such as Peroxidase and Superoxide dismutase [Fe]2, chloroplastic were also found up-regulated. The transcription factors MYB26, NAC43, and NAC73 are thought to be transcription factors involved in the defense responses to D. aromatica in peat stress treatment. Molecular phylogeny analysis was carried out on the sequences of genes related to the adaptability of D. aromatica to the peat media stress to determine the evolutionary history, kinship relationships, and related gene functions. Homologous genes show different expression up-/down-regulations patterns. However, the alignment and phylogenetic analysis results showed an identity matrix and a distance matrix showing differences between up-regulated and down-regulated homologous genes. The differences between these genes are thought to be due to differences in the specific motifs of their constituent bases.
Keyword: adaptation, Dryobalanops, phylogenetic, Transcriptome, RNA-seq

Judul: Hydroxyapatite-Chitosan Composite Coating on Stainless Steel 316 to Improve Corrosion Resistance
Abstrak: Metals that were used in bone implantation should have good corrosion resistance that were not easily corroded when implanted into the body. Metal corrosion resistance of stainless steel 316 can be enhanced through the metal coating by hydroxyapatite-chitosan composite with composition ratio of hydroxyapatite (gram) and chitosan 3% (mL) 0.2:0, 0.2:0.1, 0.2:0.5, 0.2:1.0, and 0.2:1.5. Besides improving the corrosion resistance of metal, the presence of chitosan also maintain the position of hydroxyapatite on metal surfaces. Corrosion resistance increases with increasing amount of chitosan added and the best composition of hydroxyapatite-chitosan composite was 0.2:1.0.
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