Efficient and heritable transformation of Phalaenopsis orchids
However, investigation of these features and validation on their biological functions are limited due to the lack of an efficient transformation method.
Researchers have developed an heritable and efficient Agrobacterium-mediated transformation using protocorms derived from tetraploid or diploid Phal. orchids.
A T-DNA vector construct containing eGFP driven by ubiquitin promoter was subjected to transformation. An approximate 1.2–5.2 % transformation rate was achieved.
Genomic PCR confirmed that hygromycin selection marker, HptII gene and target gene eGFP were integrated into the orchid genome. Southern blotting indicated a low T-DNA insertion number in the orchid genome of the transformants.
Western blot confirmed the expression of eGFP protein in the transgenic orchids. Furthermore, the GFP signal was detected in the transgenic orchids under microscopy.
After backcrossing the pollinia of the transgenic plants to four different Phal. orchid varieties, the BC1 progenies showed hygromycin resistance and all surviving BC1 seedlings were HptII positive in PCR and expressed GFP protein as shown by western blot.
The study demonstrated a stable transformation system was generated for Phalaenopsis orchids. This useful transformation protocol enables functional genomics studies and molecular breeding.
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