Karakterisasi Ekspresi Gen Embriogenesis selama Fase Regenerasi dengan Perlakuan Kombinasi Hormon Auksin dan Sitokinin pada Kultur Kapas (Gossypium hirsutum L.)

Abstract

Exogenous hormones can be used within media to meet the high efficiency on plant regeneration during somatic embryogenesis. In Indonesian cotton plants, the efficiency of regeneration media as indicated by the morphological response of cotton plants and the expression of embryogenesis genes needs to be studied. The aims of this study were to determine the effect of 2,4-D and IBA hormones on the morphology and induction of cotton callus; to determine the effect of regeneration media with the different combination of auxin and cytokinin on the morphology and gene expression of cotton plant during embryogenesis. This research was conducted by inducing cotton callus on MS0 medium, MS Basal + 0.1 mg/L 2,4-D and MS Basal + 0.1 mg/L IBA. The best callus induction results were regenerated on regeneration media M1 (MS Vitamin + 0.01 ppm 2,4-D + 0.3 ppm IBA + 0.5 ppm Kinetin), M2 (MS Vitamin + 0.01 ppm 2,4-D + 0.5 ppm IBA + 0.5 ppm Kinetin), M3 (MS Vitamin + 0.00 ppm 2,4-D + 0.3 ppm IBA + 0.5 ppm Kinetin), and M4 (MS Vitamin + 0, 00 ppm 2,4-D + 0.5 ppm IBA + 0.5 ppm Kinetin). Embryogenesis gene expression was observed through RNA isolation, cDNA synthesis, PCR, and visualization methods. The best morphological results for callus induction were obtained on MS Basal + 0.1 mg/L 2,4-D medium with a compact and white callus texture character that indicates high embryogenic and regeneration ability. In the regeneration phase, the highest percentage of regenerated callus parameters was found in M2 media. Several embryogenesis genes were expressed such as GhSERK1, GhSERK2, LEC, GhWUS, and GhWOX11. The best regeneration media with morphological parameters and embryogenesis gene expression was obtained on M2 media.