Overexpression of StGA2ox1 Gene Increases the Tolerance to Abiotic Stress in Transgenic Potato (Solanum tuberosum L.) Plants

It has been known that GA2ox is one kind of key enzyme gene in the gibberellin synthesis pathway, which plays important regulatory roles throughout plant whole growth and development. In this article, one of the GA2ox family genes, designated StGA2ox1, was isolated from potato (Solanum tuberosum L.). The full length of cDNA is 1005bp, and the cDNA corresponds to a protein of 334 amino acids; this protein was classified in a group with NtGA2ox3 based on multiple sequence alignments and phylogenetic characterization. A plant expression vector pCAEZ1383-StGA2ox1 was established. qRT-PCR showed that the expression of RD28, DREB1, WRKY1, and SnRK2 genes in StGA2ox1 transgenic plant is higher than that in non-transformed control under dehydration, low temperature conditions, and abscisic acid treatments. Overexpression of StGA2ox1 cDNA in transgenic potato plants exhibited an improved salt, drought, exogenous hormone, and low temperature stress tolerance in comparison to the non-transformed plant. The enhanced stress tolerance may be associated with the subsequent accumulation of proline osmoprotectant in addition to a better control of chlorophyll, carotenoids, and water loss. These data suggest that the StGA2ox1 is involved in the regulation of plant growth and tolerance in potato by regulating the synthesis of gibberellin.