Identification of drought stress-responsive genes from drought-tolerant groundnut cultivar (Arachis hypogaea L. cv K-134) through analysis of subtracted expressed sequence tags

Abstract

Drought is one of the major abiotic stresses limiting crop productivity in arid and semi-arid regions and influences many aspects of plant development. Groundnut (Arachis hypogaea L.) is an important oil yielding crop and considered as relatively drought tolerant. In this study, two groundnut cultivars were first tested for their drought tolerance based on physiological marker attributes such as relative water content, total chlorophyll content, cell membrane stability and free proline content and identified cultivar K-134 as a drought tolerant and cultivar JL-24 as drought susceptible. To gain a better understanding of the drought stress responses at molecular level, we carried out a genomic analysis of stress-responsive genes/transcripts in drought-tolerant cultivar K-134. As a first step toward characterization of stress-responsive genes, construction and analysis of subtracted cDNA library from droughttolerant cultivar (K-134) is reported here. Using this strategy a total of 200 ESTs were isolated, sequenced, of which 120 high-quality ESTs were obtained and clustered. Further, our analysis revealed that 31% sequences were unique and no homology to known proteins in the database. This observation has great relevance since groundnut is a stress-adapted legume crop. Further, to validate the identified differentially expressed genes, expression profiles of selected clones were analyzed using dot blot (reverse northern), northern blot analysis. We showed that these clones are differentially expressed under different abiotic stress conditions. The implications of the analyzed genes in abiotic stress tolerance were discussed.

Transcriptome Profiling of Wild Arachis from Water-Limited Environments Uncovers Drought Tolerance Candidate Genes

“…Among these unigenes, 194 (68.3 %) had significant BLASTN hits (using default parameters) with at least one contig present in A. duranensis 454 libraries, suggesting that A. duranensis and A. magna share some of the genes involved in the signaling pathways in response to water deficit. BLASTX and Blast2GO algorithms revealed that approximately half of these sequences (48 %) had significant matches to genes encoding proteins with known functions, in accordance to previous Arachis transcriptome studies on peanut or AA genome Arachis species (Ding et al 2014 ; Govind et al 2009 ; Guimaraes et al 2012 ; Guo et al 2008 ; Li et al 2014 ; Proite et al 2007 ; Ranganayakulu et al 2011 ; Tirumalaraju et al 2011 ). Therefore, these A. magna unigenes represent the first functionally annotated transcriptome analysis for a BB genome of an Arachis species.…”

“…Peanut has a large tetraploid genome, and its genetic studies have been hindered over the years by the scarcity of genomic resources (Brasileiro et al 2014 ; Holbrook et al 2011 ; Pandey et al 2012 ) such as physical maps, a comprehensive transcriptome database, and a fully sequenced genome, which is now on the verge of being accomplished by the International Peanut Genome Initiative (IPGI; http://www.peanutbioscience.com/homepage.html ). In addition, only recently, studies identifying genes associated with drought stress responses using transcriptome approaches for the genus Arachis have become available (Ding et al 2014 ; Govind et al 2009 ; Guimaraes et al 2012 ; Jain et al 2001 ; Li et al 2014 ; Luo et al 2005 ; Ranganayakulu et al 2011 ).…”

Global transcriptome analysis of two wild relatives of peanut under drought and fungi infection

“…[3,4,22,23]. However, to our knowledge, no massal transcriptome analysis in stressed wild Arachis is available.…”

“…Functional genomics studies, using microarrays and subtractive libraries (SSH), identified genes potentially associated to stress responses to C. personatum and drought stress in Arachis spp. [ 3 , 4 , 22 , 23 ]. However, to our knowledge, no massal transcriptome analysis in stressed wild Arachis is available.…”

Past, Present and Future Perspectives on Groundnut Breeding in Burkina Faso

“…As a legume crop, groundnut cultivation improves soil fertility and productivity by fixing atmospheric nitrogen [13]. Additionally, the plant's haulm and by-products have value as a feed for livestock [14,15]. The groundnut value chain in Burkina Faso employs a significant number of people and contributes substantially to the economy [4,16] and to family wellbeing [6,17].…”