title: Molecular Characterization of RiceOsLCB2a1Gene and Functional Analysis of its Role in Insect Resistance.
abstract: In plants, sphingolipids, such as long-chain bases (LCBs), act as bioactive molecules in stress responses. Until now, it is still not clear if these lipids are involved in biotic stress responses to herbivore. Herein we report that a rice LCB gene,OsLCB2a1encoding a subunit of serine palmitoyltransferase (SPT), a key enzyme responsible for thede novobiosynthesis of sphingolipids, plays a critical role in plant defense response to the brown planthopper (BPH) attack and that its up-regulation protects plants from herbivore infestation. Transcripts ofOsLCB2a1gene in rice seedlings were increased at 4 h, but decreased at 8-24 h after BPH attack. Sphingolipid measurement profiling revealed that overexpression ofOsLCB2a1inArabidopsis thalianaincreased trihydroxylated LCB phytosphingosine (t18:0) and phytoceramide by 1.7 and 1.3-fold, respectively, compared with that of wild type (WT) plants. Transgenic Arabidopsis plants also showed higher callose and wax deposition in leaves than that of WT. Overexpression ofOsLCB2a1gene inA. thalianareduced the population size of green peach aphid (Myzus persicae). Moreover, the electrical penetration graph (EPG) results indicated that the aphids encounter resistance factors while reaching for the phloem on the transgenic plants. The defense response genes related to salicylic acid signaling pathway, remained uplgulated in theOsLCB2a1-overexpressing transgenic plants. Our data highlight the key functions ofOsLCB2a1in biotic stress response in plants.
authors.affiliation: State Key Laboratory of Rice Biology, Key Laboratory of Agricultural Entomology, Ministry of Agriculture and Institute of Insect Sciences, Zhejiang University Hangzhou, China.
authors.forename: Mahfuj A
authors.initials: MA
authors.lastname: Begum
authors.affiliation: State Key Laboratory of Rice Biology, Key Laboratory of Agricultural Entomology, Ministry of Agriculture and Institute of Insect Sciences, Zhejiang University Hangzhou, China.
authors.forename: Xiao-Xiao
authors.initials: XX
authors.lastname: Shi
authors.affiliation: State Key Laboratory of Rice Biology, Key Laboratory of Agricultural Entomology, Ministry of Agriculture and Institute of Insect Sciences, Zhejiang University Hangzhou, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Tan
authors.affiliation: State Key Laboratory of Rice Biology, Key Laboratory of Agricultural Entomology, Ministry of Agriculture and Institute of Insect Sciences, Zhejiang University Hangzhou, China.
authors.forename: Wen-Wu
authors.initials: WW
authors.lastname: Zhou
authors.affiliation: Stony Brook Cancer Center, Department of Medicine, The State University of New York at Stony Brook New York, NY, USA.
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Hannun
authors.affiliation: Stony Brook Cancer Center, Department of Medicine, The State University of New York at Stony Brook New York, NY, USA.
authors.forename: Lina
authors.initials: L
authors.lastname: Obeid
authors.affiliation: Stony Brook Cancer Center, Department of Medicine, The State University of New York at Stony Brook New York, NY, USA.
authors.forename: Cungui
authors.initials: C
authors.lastname: Mao
authors.affiliation: State Key Laboratory of Rice Biology, Key Laboratory of Agricultural Entomology, Ministry of Agriculture and Institute of Insect Sciences, Zhejiang University Hangzhou, China.
authors.forename: Zeng-Rong
authors.initials: ZR
authors.lastname: Zhu
keywords: Arabidopsis; Myzus persicae; electrical penetration graph; insect resistance; long-chain base; serine palmitoyltransferase; sphingolipids