Metabolic interplay between cytosolic phosphoenolpyruvate carboxylase and mitochondrial alternative oxidase in thermogenic skunk cabbage, Symplocarpus renifolius. (1st November 2016)

• Record Type: Journal Article
• Authors: Sayed, Md. Abu; Umekawa, Yui; Ito, Kikukatsu
• Is Part Of: Plant signaling & behavior. Volume 11:Number 11(2016)
• Publication Date: 2016-11-01
• Subjects: Alternative oxidase -- mitochondria -- phosphoenolpyruvate carboxylase -- respiration -- skunk cabbage -- thermogenesis; Plant ecophysiology -- Periodicals; Plant cellular signal transduction -- Periodicals; Plant cellular signal transduction; Plant ecophysiology; Periodicals; Electronic journals; 581
• DOI: 10.1080/15592324.2016.1247138
• Languages: English
• ISSNs: 1559-2316

Abstract

ABSTRACT: Skunk cabbage ( Symplocarpus renifolius ) blooms in early spring and its inflorescence, referred to as the spadix, can produce enough heat to melt snow. Here, we investigated glycolytic carbon flow at the PEP branch-point in thermogenic spadices. Our analyses revealed that petals and pistils in thermogenic florets exhibited higher expression of SrPEPC and SrAOX transcripts than those of SrPK, SrPEPCK, and SrPEPtase . Moreover, enzymatic analyses showed high activities of PEPC in the extracts from thermogenic florets. Finally, mitochondria from thermogenic florets showed low respiratory activities when pyruvate was used as a substrate, although a significant malate-mediated cyanide-insensitive respiration was observed. Collectively, these results suggest that PEP metabolism, primarily catabolized by PEPC, plays a critical role in thermogenesis in S. renifolius .