Sayed Md Abu, Umekawa Yui, Ito Kikukatsu
a United Graduate School of Agricultural Science , Iwate University , Ueda, Morioka, Iwate , Japan.
b Cryobiofrontier Research Center , Faculty of Agriculture, Iwate University , Ueda, Morioka, Iwate , Japan.
Plant Signal Behav. 2016 Nov;11(11):e1247138. doi: 10.1080/15592324.2016.1247138.
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.
臭菘（Symplocarpus renifolius）在早春开花，其花序（称为肉穗花序）能产生足够的热量来融化积雪。在此，我们研究了产热肉穗花序中磷酸烯醇丙酮酸（PEP）分支点处的糖酵解碳流。我们的分析表明，产热小花中的花瓣和雌蕊比SrPK、SrPEPCK和SrPEPtase表现出更高的SrPEPC和SrAOX转录本表达。此外，酶活性分析显示产热小花提取物中PEPC的活性较高。最后，当以丙酮酸为底物时，产热小花的线粒体显示出较低的呼吸活性，尽管观察到显著的苹果酸介导的氰化物不敏感呼吸。总的来说，这些结果表明，主要由PEPC分解代谢的PEP代谢在臭菘的产热过程中起关键作用。
