Tomato DCL2b is required for the biosynthesis of 22-nt small RNAs, the resulting secondary siRNAs, and the host defense against ToMV  

作　　者：Tian Wang Zhiqi Deng Xi Zhang Hongzheng Wang Yu Wang Xiuying Liu Songyu Liu Feng Xu Tao Li Daqi Fu Benzhong Zhu Yunbo Luo Hongliang Zhu 

机构地区：[1]College of Food Science and Nutritional Engineering,China Agricultural University,100083,Beijing,China [2]Key Laboratory of Horticultural Plant Biology,Ministry of Education,College of Horticulture and Forestry Sciences,Huazhong Agricultural University,430070,Wuhan,China [3]State Key Laboratory of Protein and Plant Gene Research,College of Life Sciences,Peking University,100871,Beijing,China [4]State Key Laboratory of Plant Genomics,Institute of Genetics and Developmental Biology,Chinese Academy of Sciences,100101,Beijing,China [5]State Key Laboratory of Agro-Biotechnology,College of Biological Sciences,China Agricultural University,100193,Beijing,China [6]National Maize Improvement Center,China Agricultural University,100193,Beijing,China [7]Institute of Environment and Sustainable Development in Agriculture,Chinese Academy of Agricultural Sciences,100081,Beijing,China

出　　处：《Horticulture Research》2018年第1期359-372,共14页园艺研究（英文）

基　　金：This research was supported by grants from the National Natural Science Foundation of China(31471921,91540118,31622050,and 31672208)to H.Z;T.W.was supported by a fellowship from the Chinese Scholarship Council.

摘　　要：The tomato encode four functional DCL families,of which DCL2 is poorly studied.Here,we generated loss-of-function mutants for a tomato DCL2 gene,dcl2b,and we identified its major role in defending against tomato mosaic virus in relation to both natural and manual infections.Genome-wide small RNA expression profiling revealed that DCL2b was required for the processing 22-nt small RNAs,including a few species of miRNAs.Interestingly,these DCL2b-dependent 22-nt miRNAs functioned similarly to the DCL1-produced 22-nt miRNAs in Arabidopsis and could serve as triggers to generate a class of secondary siRNAs.In particular,the majority of secondary siRNAs were derived from plant defense genes when the plants were challenged with viruses.We also examined differentially expressed genes in dcl2b through RNA-seq and observed that numerous genes were associated with mitochondrial metabolism and hormone signaling under virus-free conditions.Notably,when the loss-of-function dcl2b mutant was challenged with tomato mosaic virus,a group of defense response genes was activated,whereas the genes related to lipid metabolism were suppressed.Together,our findings provided new insights into the roles of tomato DCL2b in small RNA biogenesis and in antiviral defense.

关 键 词：METABOLISM TOGETHER function 

分 类 号：S64[农业科学—蔬菜学]