Complex sentence: PRSV's coat protein gene was inserted into highly embryogenic plant tissue by using the newly invented gene gun, which led to the development of the transgenic line 55-1, which was proven to be effective at controlling Hawaiian strains of PRSV.
Split into simpler sentences: PRSV's coat protein gene was inserted into highly embryogenic plant tissue by using the newly invented gene gun, which led to the development of the transgenic line 55-1. Line 55-1 was proven to be effective at controlling Hawaiian strains of PRSV.