Identification and Characterization of Translational Recoding in Response to Environmental Stress.

We have documented in plant cells and plants that elevated expression of the lysyl tRNA synthetase (KRS) promotes altered charging of tRNAs and translational recoding of proteins (Wu et al., 2007). KRS is induced by iron deprivation (associated with high pH or flooding) in a variety of plants, including Lycopersicon esculentum (Giritch et al, 1997), Arabidopsis thaliana (Thimm et al., 2001) and Oryza sativa L. (Kobayashi et al., 2005); as well as drought-stressed Zea Mays (Li et al., 2007). Database search (www.maizearray.org) also reveals that KRS is up-regulated in maize under different abiotic stress, such as heat stress, UV-B or Al treatment.  The polyclonal antibodies we have raised against bacteria expressed sorghum KRS protein are capable of recognizing orthologs in rice, sorghum and even Arabidopsis thaliana. The expression profiles of KRS with respect to different stress conditions have been detected and monitored by western blot with KRS specific antibodies.