Bread wheat (Triticum aestivum L.) is the most widely grown crop of the world which is grown over 220 million hectares. It caters staple food need of 30% of global population. It has been projected that climate change may adversely affect the wheat production by 29%. Since for one degree celsius rise in global temperature, there is decline of wheat productivity by 6%, thus by 2080 projected global temperature of 4.5 degree Celsius will further compound the demand gap. Global increase in population with climate change has resulted into major challenge for water and food security. Thus, drought tolerant cultivars are required to mitigate situation of famine and food crisis fetching economic and social stability. Since, transgenic approach for increase in drought tolerance has not contributed in development of drought tolerant wheat varieties, thus there is a greater need to accelerate conventional breeding program supplementing by associated molecular markers.
Although drought related gene/QTL identification for improvement of wheat varieties for drought tolerance has been reported, but there is limitation of poor resolution beyond 10cM and limited resolving power of the individual techniques. Also, WheatExp database (https://wheat.pw.usda.gov/WheatExp/), does not have drought transcriptome of root tissue having contrasting genotype. WDRoTDb (Wheat drought root transcriptome database) catalogues 45139 candidate genes in root of flag leaf stage in wheat using contrasting genotypes of drought tolerance (NI5439) and susceptibility (WL711) by its transcriptional profiling along with gene regulatory network. It also has 28807 putative SSR markers along with the primers and 276369 and 130653 common variants from de-novo and reference based, respectively. Using de novo transcriptome assembly as a reference, a total of 420194 variants where as in case of wheat genome as reference, a total of 215186 variants were obtained and catalogued in database. A total of 69 hub genes were identified in all the four sets of data and 13820 transcriptional factors are found out of 45139 DEGs. All these information are well catalogued in the WDRoTDb. The transcriptome characterizations of NI5439 and WL711 and its web resource in the form of WDRoTDb will serve as valuable resources for new genes discovery as well as developing SSR markers.
