Highly Efficient Biolistic Transformation of Embryogenic Cell Suspensions of Banana Via a Liquid Medium Selection System

Abstract

<jats:p>An efficient biolistic transformation system of banana combined with a liquid medium selection system was developed during this study. An embryogenic cell suspension (ECS) of <jats:italic>Musa acuminata</jats:italic> cv. Baxi (AAA) was bombarded with a particle delivery system. After 7 days of restoring culture in liquid M2 medium, embryogenic cells were transferred to a liquid selection M2 medium supplemented with 10 μg/mL hygromycin for resistance screening. The untransformed cell clusters were inhibited or killed, and a small number of transformants proliferated in the liquid selection medium. After the 0th, first, second, and third generation of antibiotic screening, there were 0, 65, 212, and 320, respectively, vitality-resistant buds obtained from a 0.5-mL packed cell volume (PCV) of embryogenic cell suspension. The <jats:italic>β</jats:italic>-glucuronidase (GUS) staining, polymerase chain reaction (PCR) analysis, and Southern blot hybridization results all demonstrated a 100% positive rate of regenerated resistant seedlings. Interestingly, the number of buds obtained through third-generation screening was almost equal to that obtained from the original ECS in M2 medium without antibiotics. These results suggested that the liquid medium selection system facilitated the proliferation of a positive transgenic ECS, which significantly improved the regeneration rate of transformants. This protocol is suitable for the genetic transformation of all banana genotypes and is highly advantageous to varieties with low callusing potential.</jats:p>

Genetic Characteristics and Metabolic Interactions between Pseudocercospora fijiensis and Banana: Progress toward Controlling Black Sigatoka

“…The many challenges in banana breeding programs argue for transgenic approaches for the development of resistant cultivars. Transformation protocols for banana have been developed [ 151 , 152 , 153 ], and a better understanding of P. fijiensis pathogenicity genes may help identify potential transgenes to engineer black Sigatoka resistance in banana. Genetic modification can be performed in an agronomically desirable genetic background, which would minimize problems that could otherwise arise from conventional breeding with resistant but agronomically undesirable banana varieties.…”