**4. Pineapple**

The first report on the using of the biolistic method for gene transformation of pineapple was published by [28]. They introduced an efficient system for transformation of protocorm-like bodies with *gus*/*npt*II genes and then confirmed the gene insertions at one to three loci by Southern hybridization. After that, the published results [29–31] indicated that the pineapple cv. Phuket to herbicide Basta® X (with glufosinate ammonium as the active component) can be resisted by transforming with *bar* gene using biolistic transformation method. The transgenic plants showed herbicide tolerance when they were sprayed with herbicide (with twice the routine dose which used in the field) and remained green and healthy after 7 months, whereas the non-transformed plants became necrotic and died after 21 days. The stable integration of the *bar* gene in to the genome of the transformed plants was confirmed with PCR, RT-PCR, and Southern analyses after 380 days.

One of the physiological disorders which limited the industry of the pineapple in different area productions in the world such as Australia is the internal browning or blackheart. This disorder causes severe loss when appearing at conditions with day/night temperatures below 25/20°C with low light during fruit development and also during storage and shipment [32, 33]. To control the internal browning by the molecular breeding methods, an effort was made by [32] in order to obtain a transgene resistant to blackheart through biolistic method. The leaf callus of Smooth Cayenne cultivar was bombarded with gold particles coated with pART7 plasmid harboring PINPPO1 gene (pineapple polyphenol oxidase gene) which could successfully attain resistant plants to blackheart with an efficiency of 0.21–1.5% based on the PCR and Southern blot analysis (**Table 1**). Recent studies demonstrated that low temperature (5°C) could reduce blackheart through upregulated *AcGA2ox* gene and reduce GA4 levels compared to the higher temperature (20°C) [33]. Also, the Del Monte Foods company introduces a red-fleshed pineapple "Rosé" by overexpression/suppression of some genes related to lycopene accumulation [34].
