RESUMO
Abstract: Total RNA was isolated from Siraitia grosvenorii fruit by the method of modified Trizol, according to S. grosvenorii fruit characteristics of rich phenols, polysaccharide, oil and proteins. The OD260/280, OD260/230, RNA integrity (RIN) and yield of the total RNA with this method were 2.01, 2.02, 9.50 and 260 mirog.g-1, respectively. The open reading frame (ORF) of dehydroascorbate reductase (DHAR), named as SgDHAR, was cloned by rapid amplification of cDNA ends (RACE) and RT-PCR method from S. grosvenorii. The GenBank accession number for this gene is KC907731. The SgDHAR gene contains a full-length cDNA of 1,252 bp including ORF of 819 bp and encodes a predicted protein of 272 amino acids. The molecular mass is 30.217 7 kD and the isoelectric point is 8.76. Homology comparison showed that it shared 87% nucleotide sequence homology with Cucumis sativus. Expression patterns using qRT-PCR analysis showed that SgDHAR was mainly expressed in fruit and stem, followed by flower, and was lowest in root, while the expression level was 6.83 times in triploid. T than that in diploid. Therefore, SgDHAR gene may be involved in abortion of triploid seedless S. grosvenorii.