STUDI TRANSKRIPTOMIK KOMPARATIF UNTUK MENDESKRIPSIKAN PENGARUH PEMATANGAN BUAH TERHADAP EKSPRESI GEN YANG BERPERAN DALAM METABOLISME KAROTENOID PADA MUSA ACUMINATA ‘CAVENDISH’ (GENOM A) DAN MUSA BALBISIANA ‘PISANG KLUTUK WULUNG’ (GENOM B)

• Main Author: Octaviora Ruhyaman, Ericka
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/55476
• Institution: Institut Teknologi Bandung

Provitamin A carotenoids (PVACs) is one of the most important nutritional content that bananas have and are built from two main components, namely ?- and ?-carotene. The results of the analysis of banana carotenoid profiles in previous studies showed that the pVAC content of A genome banana was higher than that of B genome banana, but when the both were crossed there were hybrid cultivars with higher pVAC content than the A genome banana itself, so it was necessary to identify the genes that contributed to these results for each genome. Therefore, this study aims to analyze the expression level of genes and transcription factors in the metabolic pathways of carotenoids that control the production of PVAC in Cavendish (A genome) and Pisang Klutuk Wulung (PKW) (B genome) cultivars. In this study, comparative transcriptomic analysis was conducted on different ripening days, namely the 1st and 7th days. The analysis was using data from the previous research, with accession numbers SRP227182 (Cavendish) and SRP293766 (PKW). The method used is the Tuxedo protocol, then visualized with CummeRbund and conducted follow-up analysis using KOBAS and AgriGO. The analysis results in Cavendish bananas showed that genes related to carotenoid metabolism include abscisic acid 8'-hydroxylase 1 (ABA8-Ox), lycopene epsilon cyclase (LCYE), lutein deficient protein 5 (LUT5), and lycopene beta cyclase (LCYB) which experienced a significant increase in expression on the 7th ripening day and carotene epsilon-monooxygenase (?-OHase), 15-cis-zeta-carotene isomerase (Z-ISO), beta-carotene 3-hydroxylase (?-OHase), carotenoid 9,10-cleavage dioxygenase (CCD), and phytoene desaturase (PDS) which experienced a significant decrease in the expression on the 7th ripening day. Meanwhile, analysis of PKW showed that ABA8-Ox experienced a significant increase in expression on the 7th ripening day, as well as ?-OHase and cytochrome p450 (CYP) which experienced a significant decrease in the expression on the 7th ripening day, while LCYE, LUT5, LCYB, ?-OHase, Z-ISO, CCD, and PDS were not significantly expressed. LCYE and LCYB have been known to have a direct role in controlling the biosynthesis of ?-carotene and ?-carotene while CCD that regulates carotenoid degradation have a key role in the carotenoid pathway so the identification of the expression level of transcription factors (TF) that regulates it was conducted. The TF expression levels of these three key genes in Cavendish bananas were found to significantly increase on the 7th day of ripening, indicating the probability of expression induction of these three key genes in Cavendish bananas. Meanwhile, in PKW found that the TF of LCYB and LCYE expressed significantly decreased, and the TF of CCD was not expressed significantly. The results of this in silico analysis showed that in the process of ripening bananas on the 1st and 7th day have similarities by expressed 2 carotenoid genes in both cultivars, and differences by expressed 7 other carotenoid genes only in Cavendish banana leading to the variability of carotenoid levels of various banana cultivars. This research can be continued to confirm the expression of these genes with qPCR to establish their role in carotene synthesis in bananas.