Understanding germline specification in plants could be advantageous for agricultural applications.In recent decades,substantial efforts have been made to understand germline speci fication in several plant species,in...Understanding germline specification in plants could be advantageous for agricultural applications.In recent decades,substantial efforts have been made to understand germline speci fication in several plant species,including Arabidopsis,rice,and maize.However,our knowledge of germline speci fication in many agronomically important plant species remains obscure.Here,we characterized the female germline speci fication and subsequent female gametophyte development in pineapple using callose staining,cytological,and whole-mount immunolocalization analyses.We also determined the male germline speci fication and gametophyte developmental timeline and observed male meiotic behavior using chromosome spreading assays.Furthermore,we identi fied 229 genes that are preferentially expressed at the megaspore mother cell(MMC)stage during ovule development and 478 genes that are preferentially expressed at the pollen mother cell(PMC)stage of anther development using comparative transcriptomic analysis.The biological functions,associated regulatory pathways and expression patterns of these genes were also analyzed.Our study provides a convenient cytological reference for exploring pineapple germline development and a molecular basis for the future functional analysis of germline speci fi cation in related plant species.展开更多
Deposition of the histone variant H2A.Z at gene bodies regulates transcription by modifying chromatin accessibility in plants. However, the role of H2A.Z enrichment at the promoter and enhancer regions is unclear, and...Deposition of the histone variant H2A.Z at gene bodies regulates transcription by modifying chromatin accessibility in plants. However, the role of H2A.Z enrichment at the promoter and enhancer regions is unclear, and how H2A.Z interacts with other mechanisms of chromatin modification to regulate gene expression remains obscure. Here, we mapped genome-wide H2A.Z, H3K4me3, H3K27me3, Pol II, and nucleosome occupancy in Arabidopsis inflorescence. We showed that H2A.Z preferentially associated with H3K4me3 at promoters, while it was found with H3K27me3 at enhancers, and that H2A.Z deposition negatively correlated with gene expression. In addition, we demonstrated that H2A.Z represses gene expression by establishing low gene accessibility at ＋1 nucleosome and maintaining high gene accessibility at -1 nucleosome. We further showed that the high measures of gene responsiveness correlate with the H2A.Z-associated closed ＋1 nucleosome structure. Moreover, we found that H2A.Z represses enhancer activity by promoting H3K27me3 and preventing H3K4me3 histone modifications. This study provides a framework for future studies of H2A.Z functions and opens up new aspects for decoding the interplay between chromatin modification and histone variants in transcrip- tional control.展开更多
基金This work was supported by the Science and Technology Program of Fujian Province(2019N5008)the Science and Technology Major Project of Guangxi(Gui Ke 2018-266-Z01)+2 种基金the National Natural Science Foundation of China(31970333,U1605212)a Guangxi Distinguished Experts Fellowship awarded to Y.Qa Science and Technology Major Project of Guangxi-Research and application of ecological and highly efficient cultivation techniques for dominant and characteristic fruits(AA17204097-6)awarded to X.W.
文摘Understanding germline specification in plants could be advantageous for agricultural applications.In recent decades,substantial efforts have been made to understand germline speci fication in several plant species,including Arabidopsis,rice,and maize.However,our knowledge of germline speci fication in many agronomically important plant species remains obscure.Here,we characterized the female germline speci fication and subsequent female gametophyte development in pineapple using callose staining,cytological,and whole-mount immunolocalization analyses.We also determined the male germline speci fication and gametophyte developmental timeline and observed male meiotic behavior using chromosome spreading assays.Furthermore,we identi fied 229 genes that are preferentially expressed at the megaspore mother cell(MMC)stage during ovule development and 478 genes that are preferentially expressed at the pollen mother cell(PMC)stage of anther development using comparative transcriptomic analysis.The biological functions,associated regulatory pathways and expression patterns of these genes were also analyzed.Our study provides a convenient cytological reference for exploring pineapple germline development and a molecular basis for the future functional analysis of germline speci fi cation in related plant species.
文摘Deposition of the histone variant H2A.Z at gene bodies regulates transcription by modifying chromatin accessibility in plants. However, the role of H2A.Z enrichment at the promoter and enhancer regions is unclear, and how H2A.Z interacts with other mechanisms of chromatin modification to regulate gene expression remains obscure. Here, we mapped genome-wide H2A.Z, H3K4me3, H3K27me3, Pol II, and nucleosome occupancy in Arabidopsis inflorescence. We showed that H2A.Z preferentially associated with H3K4me3 at promoters, while it was found with H3K27me3 at enhancers, and that H2A.Z deposition negatively correlated with gene expression. In addition, we demonstrated that H2A.Z represses gene expression by establishing low gene accessibility at ＋1 nucleosome and maintaining high gene accessibility at -1 nucleosome. We further showed that the high measures of gene responsiveness correlate with the H2A.Z-associated closed ＋1 nucleosome structure. Moreover, we found that H2A.Z represses enhancer activity by promoting H3K27me3 and preventing H3K4me3 histone modifications. This study provides a framework for future studies of H2A.Z functions and opens up new aspects for decoding the interplay between chromatin modification and histone variants in transcrip- tional control.
