TRANSCRYPTOMIC ANALYSIS OF THE EFFECT OF 1.25% CHITOSAN COATING ON LECTIN GENE EXPRESSION IN CAVENDISH BANANA FRUIT (MUSA ACUMINATA, AAA)

• Main Author: Lestari Wulan Utami, Restu
• Format: Final Project
• Language: Indonesia
• Subjects: Ilmu hayati ; Biologi
• Online Access: https://digilib.itb.ac.id/gdl/view/55412
• Institution: Institut Teknologi Bandung

Bananas contain lectins, which are proteins that have a binding domain on carbohydrate. The unique lectin in bananas is the banana lectin (BanLec) which is able to recognize mannose. One type of banana that has the potential as a source of lectins is the Cavendish banana abundant availability in Indonesia. The results of research conducted by other researchers have indicating that the specific biosynthetic pathways of lectins are not yet known, the concentrations of lectins generally are at low levels, and lectin expression can be triggered by inducing factors. One compound The inducer that can be used to increase lectin levels is chitosan. On research Previously, chitosan could increase lectin levels in the chloroplast membrane of tobacco leaves. By Therefore, this study used transcriptomics data from the results of previous studies on Cavendish bananas coated with chitosan with accession number SRP227182 in Sequence Read NCBI Archive (SRA) to study the effect of chitosan on the expression of lectin genes. Objective This study is to compare the expression levels of lectin genes in Cavendish bananas coated and not coated with 1.25% chitosan on fruit skin using a transcriptomics approach. Sample The raw transcriptome data used were coated and uncoated Cavendish bananas chitosan 1.25% on the first day after chitosan coating. The raw data of RNA sequences were examined quality first using FastQC then carried out bioinformatics analysis using the Tuxedo protocol The steps in the Tuxedo protocol include aligning the RNA sequences to the reference genome using TopHat, splicing RNA sequences using Cufflinks, splicing of RNA variants using Cuffmerge, differential gene expression (DEG) analysis using Cuffdiff, and visualization of differential gene expression using CummeRbund. Analysis bioinformatics to the stage of differential gene expression analysis using Cuffdiff has also been carried out in previous research. In this study, additional analysis was carried out in the form of DEG analysis annotations using PLAZA Integrative Orthology, visualization of differential gene expression using GraphPad Prism, KEGG pathway analysis using KOBAS, gene ontology analysis using agriGO, and protein network interaction analysis using STRING and Cytoscape. Annotation results DEG analysis using PLAZA Integrative Orthology showed that 1.25% chitosan was capable induces an increase in the expression of seventeen lectin genes with a log2(fold change) range 1.00591-2.73673. The lectin gene with the lowest log2(fold change) value is Ma04_g27470 whereas the lectin gene with the highest log2(fold change) value is Ma09_g10350. Based on path analysis biosynthesis in KEGG, a lectin gene whose expression increases affects the biosynthetic pathway brasinosteroids thereby inducing the biosynthesis of the TCH4/XET enzymes. Gene ontology analysis shows significantly enriched biological processes are xyloglucan metabolic processes; the molecular function significantly enriched is the activity of xyloglucan: xyloglucosyltransferase, glucosyltransferase activity, and hydrolase activity; and significantly enriched cellular components are apoplast and wall cell. From the results of this in silico study it was suspected that there was modification or restructuring of the cell wall primers through the TCH4/XET-catalyzed cutting and recombination of xyloglucan in apoplast and cell wall due to increased expression of seventeen lectin genes. Lectins are thought to interact with other proteins that experienced increased expression due to chitosan treatment. Results This transcriptomic analysis showed that the expression of lectin genes was induced by chitosan have a tendency to play a role in plant defense. However, studies need to be carried out further to validate the results of in silico analysis in this study.