Isolation of differentially expressed genes from developing seeds of a high-protein peanut mutant and its wild type using genefishingTM technology

Abstract

Peanut is a good source of dietary protein. Raising protein content in peanut will not only fill the growing need for vegetable protein, but also in most cases lower oil content, which is good news to health-conscious populations. However, no attempt has been made to isolate genes related to protein content in peanut. In the present study, a total of 40 unique differentially expressed genes in developing seeds of high-protein peanut mutant (SDPM) and its normal-protein wild type (SDPW) at 46 or 49 days after flowering were isolated using Genefishing technology. Of them, 8 sequences were undescribed previously; the rest 32 were found to be significantly similar to the sequences in GenBank nr database. Three genes potentially related to protein content in peanut, viz., P2-2-2, P2-92-2 and P1-89-1-5 with high homology to thioredoxin h, arachin ahy-4 and abc transporter, respectively, were selected for further analysis. All the 3 genes validated by qRT-PCR showed differential expression between SDPM and SDPW, with relative expression ranging from 0.41–10. 60. The detailed functions of the differentially expressed genes isolated from developing seeds in the present study in conditioning peanut seed protein content are yet to be validated by transgenic experiments.