Cloning of TPS gene from eelgrass species Zostera marina and its functional identification by genetic transformation in rice

• A TPS gene (ZmTPS) was cloned from a kind of seed-plant growing in sea water.
• Genome DNA of the ZmTPS gene contains 3 exons and 2 introns.
• ZmTPS gene was higher similarity with TPS gene from rice than that from Arabidopsis.
• The ZmTPS gene was transformed and expressed in a widely growing rice variety ZH11.
• Over expression of the ZmTPS gene enhanced salt-tolerance of transgenic rice plants.
• The transgenic rice showed higher trehalose accumulation than control plants.
• The ZmTPS gene can transmit stably from parent to the progeny in transgenic rice.

The full-length cDNA sequence (2613 bp) of the trehalose-6-phosphate synthase (TPS) gene of eelgrass Zostera marina (ZmTPS) was identified and cloned. Z. marina is a kind of seed-plant growing in sea water during its whole life history. The open reading frame (ORF) region of ZmTPS gene encodes a protein of 870 amino acid residues and a stop codon. The corresponding genomic DNA sequence is 3770 bp in length, which contains 3 exons and 2 introns. The ZmTPS gene was transformed into rice variety ZH11 via Agrobacterium-mediated transformation method. After antibiotic screening, molecular characterization, salt-tolerance and trehalose content determinations, two transgenic lines resistant to 150 mM NaCL solutions were screened. Our study results indicated that the ZmTPS gene was integrated into the genomic DNA of the two transgenic rice lines and could be expressed well. Moreover, the detection of the transformed ZmTPS gene in the progenies of the two transgenic lines was performed from T1 to T4 generations; and results suggested that the transformed ZmTPS gene can be transmitted from parent to the progeny in transgenic rice.