[Transformation of Volvariella volvacea with a thermal hysteresis protein gene by particle bombardment].

A cDNA encoding a thermal hysteresis protein was isolated from the Swedish Arctic insect spruce budworm by RT-PCR amplification. Volvariella volvacea strain V34 was transformed with this cDNA through particle bombardment. PCR detection and Southern blotting analysis show that the thermal hysteresis protein gene is integrated into Volvariella volvacea genome. Cold stress assay reveals that transgenic Volvariella volvacea lines exhibit stronger cold tolerance than host strain. The morphological observation of transgenic Volvariella volvacea lines shows that growth rates of most Volvariella volvacea transformants are significantly slower than that of negative control strain. And hypha of most Volvariella volvacea tansformants is thinner than host strain's hypha. Transformant screening result indicates that three-round of selection procedure with first selection on PDSA solid selective medium followed by second and third selection in PDSB liquid selective medium is favorable to get genuine transformants and to eliminate false transformants. Cold tolerance assay of transgenic Volvariella volvacea F1 generation demonstrates that the progeny of transgenic Volvariella volvacea still possesses stronger cold tolerance than non-transformed host strain. This suggests that the cold tolerant characteristic of transgenic Volvariella volvacea is meiotically stable between generations.