Reverse transcriptase (rt) fragments from LINE retrotransposons in the mulberry genome were analyzed in terms of heterogeneity, phylogeny, and chromosomal distribution. We amplified and characterized conserved domains...Reverse transcriptase (rt) fragments from LINE retrotransposons in the mulberry genome were analyzed in terms of heterogeneity, phylogeny, and chromosomal distribution. We amplified and characterized conserved domains of the rt using degenerate primer pairs. Sequence analyses indicated that the rt fragments were highly heterogeneous and rich in A/T bases. The sequence identity ranged from 31.8% to 99.4%. Based on sequence similarities, the rt fragments were categorized into eight groups. Furthermore, similar stop codon distribution patterns among a series of clones in the same group indicated that they underwent a similar evolutionary process. Interestingly, phylogenetic analyses of the rt fragments isolated from mulberry and 13 other plant species revealed that two distantly related taxa (mulberry and Paeonia suffruticosa) grouped together. It does not appear that this phenomenon resulted from horizontal transposable element transfer. Fluorescence in situ hybridization analysis revealed that most of the rt fragments were concentrated in the subtelomeric and pericentromeric regions of the mulberry chromosomes, but that these elements were not abundant in the mulberry genome. Future studies will focus on the potential roles of these elements in the subtelomeric and pericentromeric regions of the mulberry genome.展开更多
Jasmonate （JA） is an important phytohormone regulating growth, development, and environmental response in plants, particularly defense response against herbivorous insects. Recently, completion of the draft genome o...Jasmonate （JA） is an important phytohormone regulating growth, development, and environmental response in plants, particularly defense response against herbivorous insects. Recently, completion of the draft genome of the mulberry （Morus notabilis） in conjunction with genome sequencing of silkworm （Bombyx mori） provides an opportuni-ty to study this unique plant-herbivore interaction. Here, we identified genes involved in JA biosynthetic and signaling pathways in the genome of mulberry for the first time, with the majority of samples showing a tissue-biased expression pattern. The analysis of the representative genes 12-oxophy-todienoic acid reductase （OPRs） and jasmonate ZIM-domain （JAZs） was performed and the results indicated that the mulberry genome contains a relatively smal number of JA biosynthetic and signaling pathway genes. A gene encoding an＆amp;nbsp;important repressor, MnNINJA, was identified as an alternative splicing variant lacking an ethylene-responsive element binding factor-associated amphiphilic repression motif. Having this fundamental information wil facilitate future functional study of JA-related genes pertaining to mulberry-silkworm interactions.展开更多
Cytochrome P450 S play critical roles in the biosynthesis of physiologically important compounds in plants.These compounds often act as defense toxins to prevent herbivory.In the present study,a total of 174 P450 gene...Cytochrome P450 S play critical roles in the biosynthesis of physiologically important compounds in plants.These compounds often act as defense toxins to prevent herbivory.In the present study,a total of 174 P450 genes of mulberry（Morus notabilis C.K.Schn） were identified based on bioinformatics analyses.These mulberry P450 genes were divided into nine clans and 47 families and were found to be expressed in a tissue-preferential manner.These genes were compared to the P450 genes in Arabidopsis thaliana.Families CYP80,CYP92,CYP728,CYP733,CYP736,and CYP749 were found to exist in mulberry,and they may play important roles in the biosynthesis of mulberry secondary metabolites.Analyses of the functional and metabolic pathways of these genes indicated that mulberry P450 genes may participate in the metabolism of lipids,other secondary metabolites,xenobiotics,amino acids,cofactors,vitamins,terpenoids,and poiyketides.These results provide a foundation for understanding of the structures and biological functions of mulberry P450 genes.展开更多
文摘Reverse transcriptase (rt) fragments from LINE retrotransposons in the mulberry genome were analyzed in terms of heterogeneity, phylogeny, and chromosomal distribution. We amplified and characterized conserved domains of the rt using degenerate primer pairs. Sequence analyses indicated that the rt fragments were highly heterogeneous and rich in A/T bases. The sequence identity ranged from 31.8% to 99.4%. Based on sequence similarities, the rt fragments were categorized into eight groups. Furthermore, similar stop codon distribution patterns among a series of clones in the same group indicated that they underwent a similar evolutionary process. Interestingly, phylogenetic analyses of the rt fragments isolated from mulberry and 13 other plant species revealed that two distantly related taxa (mulberry and Paeonia suffruticosa) grouped together. It does not appear that this phenomenon resulted from horizontal transposable element transfer. Fluorescence in situ hybridization analysis revealed that most of the rt fragments were concentrated in the subtelomeric and pericentromeric regions of the mulberry chromosomes, but that these elements were not abundant in the mulberry genome. Future studies will focus on the potential roles of these elements in the subtelomeric and pericentromeric regions of the mulberry genome.
基金funded by research grants from the National Hi-Tech Research and Development Program of China(2013AA100605-3)the "111" Project(B12006)+1 种基金the Science Fund for Distinguished Young Scholars of Chongqing(cstc2011jjjq0010)the National Natural Science Foundation of China(31201005)
文摘Jasmonate （JA） is an important phytohormone regulating growth, development, and environmental response in plants, particularly defense response against herbivorous insects. Recently, completion of the draft genome of the mulberry （Morus notabilis） in conjunction with genome sequencing of silkworm （Bombyx mori） provides an opportuni-ty to study this unique plant-herbivore interaction. Here, we identified genes involved in JA biosynthetic and signaling pathways in the genome of mulberry for the first time, with the majority of samples showing a tissue-biased expression pattern. The analysis of the representative genes 12-oxophy-todienoic acid reductase （OPRs） and jasmonate ZIM-domain （JAZs） was performed and the results indicated that the mulberry genome contains a relatively smal number of JA biosynthetic and signaling pathway genes. A gene encoding an＆amp;nbsp;important repressor, MnNINJA, was identified as an alternative splicing variant lacking an ethylene-responsive element binding factor-associated amphiphilic repression motif. Having this fundamental information wil facilitate future functional study of JA-related genes pertaining to mulberry-silkworm interactions.
基金funded by the research grants from the National Hi-Tech Research and Development Program of China(2013AA100605-3)the "111" Project(B12006)+1 种基金the Science Fund for Distinguished Young Scholars of Chongqing(cstc2011jjjq0010)Chong Qing Science and Technology Commission(cstc2012jjys80001)
文摘Cytochrome P450 S play critical roles in the biosynthesis of physiologically important compounds in plants.These compounds often act as defense toxins to prevent herbivory.In the present study,a total of 174 P450 genes of mulberry（Morus notabilis C.K.Schn） were identified based on bioinformatics analyses.These mulberry P450 genes were divided into nine clans and 47 families and were found to be expressed in a tissue-preferential manner.These genes were compared to the P450 genes in Arabidopsis thaliana.Families CYP80,CYP92,CYP728,CYP733,CYP736,and CYP749 were found to exist in mulberry,and they may play important roles in the biosynthesis of mulberry secondary metabolites.Analyses of the functional and metabolic pathways of these genes indicated that mulberry P450 genes may participate in the metabolism of lipids,other secondary metabolites,xenobiotics,amino acids,cofactors,vitamins,terpenoids,and poiyketides.These results provide a foundation for understanding of the structures and biological functions of mulberry P450 genes.
