Roles Of StSF-2and StDH In Drought Tolerance In Potato

Drought is one of the abiotic stresses, affecting the crop production. Therefore, drought is considered to be the bottleneck of agricultural development. The impacts of water limitation on crops production will likely increase over the next decades, due to climate change. Potato (Solanum tuberosum L.) is the forth food crops due to its high yield, adaptability and nutrient fullness. A little is known on how potato is tolerant to drought condition.In our lab, four TSH libraries were constructed with leafs of two potato landraces under water stress. Two ESTs, homologous with StDH and StSF-2were identified by screening the libraries. In this study, tools on expression analysis in vitro and bioinformatics were employed to reveal function of StDH and StSF-2on drought tolerance, based on cDNA isolated with the rapid amplification of cDNA ends (RACE). Lay the theoretical foundation for the development of drought-type potato. The following results are achieved in this study.The cDNA of StDH we isolated is562bp in length and shared98%identity with sequence of StDT112reported, StDH contains an ORF with528bp, putatively encoding peptide with175amino acids. Alignment on amino acid sequences showed that StDH belonged to StDHN protein family. StSF-2,910bp in length,852bp in ORFs, putatively encoding StSF-2peptide composing of283amino acids, Two RNA recognition motifs (RRM) within StSF-2peptide were predicted by the Conserved Domain Search Service.RT-PCR was preformed with leafs mRNA of potato genotype ZHB under water stress. The result showed mRNA accumulation of StDH in leafs, under stress of WCM at10%for21days went up in the beginning and down at the end. StSF-2mRNA accumulation preceded that of StDH in leaves under the Stress. This indicates that expression of StDH and StSF-2were induced by water stress.Recombinant StDH and StSF-2were constructed and transformed into potato genotype ZHB with the agriobacterium-mediaed approach. Test on expression of15genes known on function responding to water stress revealed that StSF-2is assiocated with splicing of StDH pre-mRNA. Attenuation or absence of StSF-2expression resulted in accomulation of pre-mRNAs of CBP, OSM-8E and OSM-3F. This suggests that StSF-2may involve in splicing on pre-mRNAs of CBP, OSM-8E and OSM-3F.