Studies On Single Nucleotide Polymorphisms Of Drought Response Gene And Drought Tolerance In Lespedeza Potaninii

Lespedeza potaninii is one of the most drought tolerant legumes species which naturally distributed in arid, semi-arid and desert grassland. It is a plant model for the investigation of the individual difference of drought tolerant at single nucleotide polymorphisms (SNP) level. In the present study, the gene LpDREB, LpP5CS were cloned from the L. potaninii plants by chromosome walking and3’RACE method. The organ-and inducible-expression patterns of the LpDREB, LpP5CS gene were also revealed. Furthermore, the structure of the gene and its phylogeny and SNP type and distribution were characterized. The results areas following:(1) The full length cDN A sequence of LpDREB gene was1611bp containing a957bp open reading frame (ORF) which encodes a318amino acid residues, no intron was found in gene. Phylogeny analysis revealed that the LpDREB gene had a closest evolutionary relationship with soybean GmDREB3gene. Expression of the LpDREB gene could be induced by drought stress in all tested organs. In the L. potaninii population,23SNPs were detected. A total of12SNPs were in transitions, while11SNPs were in transversions. For the coding region located17SNPs,9were synonymous mutation and8were non-synonymous mutations.(2) The full length DNA and cDNA sequence of LpP5CS gene was6194bp and2148bp encoding a716amino acid residues. The amino acid sequence of the LpP5CS gene had a closest homology with soybean CinP5CS and kidney bean PvP5CS gene. Expression of the LpP5CS gene varied in different organs compared with the control group.176SNPs were detected from the sequence of LpP5CS and113SNPs were in transitions, while62SNPs were in transversions. For the coding region located43SNPs,19were synonymous mutation and23were non-synonymous mutations.(3) Variance and component analysis of proline, malondialdehyde content and electric conductivity from8natural provenance of Lespedeza potaninii show that the three physiological indexes have very significant difference, multiple comparison results show that the measuring of malondialdehyde content and conductivity have more meaningful for polymorphism analysis between eight provenance.All these results provided the important theory foundation for study of drought tolerance mechanism based on single nucleotide polymorphism in Lespedeza potaninii.