Biofortification of Indian banana for enhanced pro vitamin a PVA content

Abstract

Biofortification of popular Indian banana cultivars, i. e. Grand Naine and Rasthali was done to increase the pro-vitamin A (PVA) content. The work was started with Queensland University of Technology (QUT), Australia under technology transfer project. The regeneration protocol was optimized for Grand Naine and Rasthali. The lower regeneration efficiency obtained in Grand Naine was enhanced from 68% to 81% by spraying 2, 4-diphenoxyacetic acid on immature male flower buds. In-silico analysis was done to identify the nine transcription (TF) families that play a crucial role in somatic embryogenesis (SE). The higher expression of Musa acuminata babyboom 2 (MaBBM2) and Musa acuminata wuschel 2 (MaWUS2) in embryogenic cells as compared to non-embryogenic cells of Grand Naine showed their promising role in banana SE. Agrobacterium tumefaciens-mediated transformation was optimized using the and#946;-glucouronidase (GUS) reporter gene for both the cultivars. Grand Naine embrogenic cell suspension (ECS) showed lower transformation efficiency as compared to Rasthali. The number of Grand Naine transformants increased from 46.70±2.50 plantlets/ml settled cell volume (SCV) to 72.30±7.50 plantlets/ml SCV using melatonin antioxidant. In the present study, two gene constructs received from the QUT, Australia containing Asupina Phytoene synthase 2a (APSY2a) under fruit-specific (1- aminocyclopropane-1- carboxylate oxidase: ACO) and constitutive (Ubiquitin) promoters were overexpressed in both cultivars. The highest PVA/and#946;-carotene equivalents (and#946;-CE) content obtained in ripe fruit pulp of Grand Naine was up to 34.40 and#956;g/g DW and up to 72.40 and#956;g/g DW in Rasthali fruit pulp with constitutive promoter using high performance liquid chromatography (HPLC). The selected promising lines will be considered for further evaluations. newline newline newline