| Buffalograss (Buchloe dactyloides) has an inherent tolerance to drought stress making it increasingly popular for use as a turf grass. Breeding programs have developed more drought resistant varieties at the expense of the preferred blue-green hue that less-tolerant varieties possess. In order to engineer varieties that have high drought tolerance while still having the more attractive blue-green color, the molecular mechanisms of drought resistance must be characterized. Using 454 pyrosequencing, this study compares the transcriptomic expression patterns of a drought tolerant variety of buffalograss that is well-watered to clonal specimens of the same variety that have been exposed to drought. A large fraction of sequences did not show similarity with sequences in databases, and may represent buffalograss-specific genes. Sequences were classified by functional annotations using Gene Ontology terminology. No considerable differences were found in the larger GO subontologies between the two pools. An analysis of sequences encoding transcription factors in each pool show more abundant representation of the CPP, ZF-HD, TUB, bZIP, and MYB families in the drought pool. ABI3VP1, AP2-EREBP, ARR-B, CAMTA, CCAAT, EIL, GRAS, HMG, LFY, TCP, C2H2, Homeobox, NAC, and WRKY families showed an overrepresentation of transcripts in the control pool. The results of this study represent an initial look into the complexity of drought response in buffalograss. Additional studies are needed to identify target genes of the TFs seen to be over or under-expressed in drought response mechanisms and to discover molecular markers associated with loci regulating drought tolerance mechanisms. |
