Abstract: Lucine-rich-repeat receptor-like kinases (LRR-RLKs) are known to function in various signaling pathways in plants. Our previous study suggested a role for a soybean LRR-RLK, GmSARK, in regulating leaf senescence. Because constitutive expression of GmSARK leads to lethality, we used a dexamethasone (DEX)-inducible transcription system to control the expression of GmSARK in Arabidopsis thaliana. Applying DEX to the transgenic plants effectively induced the overexpression of GmSARK, thus leading to marked growth inhibition and leaf senescence. Interestingly, exogenous cytokinin (6-BA) repressed the expression of GmSARK in the transgenic lines, yet failed to restore the severe phenotypes.

Key words: Arabidopsis thaliana, cytokinin