Involvement of sphingoid bases in mediating reactive oxygen intermediate production and pr

Involvement of sphingoid bases in mediating reactive oxygen intermediate production and

programmed cell death in Arabidopsis

Lihua Shi;Yusuf A Hannun;Jianru Zuo;Jacek Bielawski;Jinye Mu;Haili Dong;Chong Teng;Jian Zhang;Xiaohui Yang;Nario Tomishige;Kentaro Hanada

【期刊名称】《细胞研究（英文版）》 【年(卷),期】2007(017)012

【摘要】Sphingolipids have been suggested to act as second messengers for an array of cellular signaling activities in plant cells, including stress responses and programmed cell death (PCD). However, the mechanisms underpinning these processes are not well understood. Here, we report that an Arabidopsis mutant, fumonisin Bl resistant11-1 (fbr11-1), which fails to generate reactive oxygen intermediates (ROIs), is incapable of initiating PCD when the mutant is challenged by fumonisin B1 (FB1), a specific inhibitor of ceramide synthase. Molecular analysis indicated that FBR11 encodes a long-chain basel (LCB1) subunit of serine palmitoyltransferase (SPT), which catalyzes the first rate-limiting step of de novo sphingolipid synthesis. Mass spectrometric analysis of the sphingolipid concentrations revealed that whereas the fbrll-1 mutation did not affect basal levels of sphingoid bases, the mutant showed attenuated formation of sphingoid bases in response to FB1 By a direct feeding experiment, we show that the free sphingoid