查看文章

Proline (Pro) accumulation occurs in various plant organisms in response to environmental stresses. To identify the signaling components involved in the regulation of Pro metabolism upon water stress in Arabidopsis (Arabidopsis thaliana), a pharmacological approach was developed. The role of phosphoinositide-specific phospholipases C (PLCs) in Pro accumulation was assessed by the use of the aminosteroid U73122, a commonly employed specific inhibitor of receptor-mediated PLCs. We found that U73122 reduced pyrroline-5-carboxylate synthetase transcript and protein as well as Pro levels in salt-treated seedlings. Inhibition of PLC activity by U73122 was quantified by measuring the decrease of inositol 1,4,5-trisphosphate (InsP₃) levels. Moreover, the utilization of diacylglycerol kinase and InsP₃-gated calcium release receptor inhibitors suggested that InsP₃ or its derivatives are essential for Pro …