L. tridentata, or desert creosote bush, is a xerophytic C3 plant native to the American Southwest, and is known to have evolutionarily developed sophisticated cellular mechanisms to deal with periods of intense abiotic stress. Particularly, complex signaling pathways in L. tridentata allow it to survive in periods of severe water deficiency. Through the findings of Zou et al. [5,6], LtWRKY21 synergistically works with abscisic acid (ABA) to transactivate both ABA-inducible HVA1 and HVA22 promoters. In addition, as ABA and gibberellic acid (GA) pathways are known to act antagonistically. Expectantly, the findings of Zou et al. suggest that LtWRKY21 activates ABA signaling pathways and represses GA signaling pathways [5,6]. More importantly, the LtWRKY21 transcription factor’s synergy with ABA is directly linked to some remarkable molecular adaptations of L. tridentata, some of which include stomatal closure to prevent transpiration, and slowing down gene expression to withstand dehydration [6]. To examine some of these mechanisms, the model plant Arabidopsis thaliana will be transformed with the LtWRKY21 coding region via Agrobacterium-mediated transformation. Successful transformants will be selected and the subsequent generation of transgenic plants will be assayed. Both phenotypic (screening) and genotypic (qRT-PCR and Southern Blot) examination will allow the function and expression patterns of LtWRKY21 to be elucidated under simulated drought. In order for LtWRKY21 to be successfully transformed into Arabidopsis, a tumor-inducing (Ti) plasmid must be engineered to carry LtWRKY21
