Tung tree(Vernicia fordii) is an economically important woody oil plant that produces tung oil rich in eleostearic acid. Here, we report a high-quality chromosome-scale genome sequence of tung tree. The genome sequenc...Tung tree(Vernicia fordii) is an economically important woody oil plant that produces tung oil rich in eleostearic acid. Here, we report a high-quality chromosome-scale genome sequence of tung tree. The genome sequence was assembled by combining Illumina short reads, Pacific Biosciences single-molecule real-time long reads, and Hi-C sequencing data. The size of tung tree genome is 1.12 Gb, with 28,422 predicted genes and over 73% repeat sequences. The V. fordii underwent an ancient genome triplication event shared by core eudicots but no further wholegenome duplication in the subsequent ca. 34.55 million years of evolutionary history of the tung tree lineage. Insertion time analysis revealed that repeat-driven genome expansion might have arisen as a result of long-standing long terminal repeat retrotransposon bursts and lack of efficient DNA deletion mechanisms. The genome harbors 88 resistance genes encoding nucleotide-binding sites;17 of these genes may be involved in early-infection stage of Fusarium wilt resistance. Further, 651 oil-related genes were identified, 88 of which are predicted to be directly involved in tung oil biosynthesis. Relatively few phosphoenolpyruvate carboxykinase genes, and synergistic effects between transcription factors and oil biosynthesis-related genes might contribute to the high oil content of tung seed. The tung tree genome constitutes a valuable resource for understanding genome evolution, as well as for molecular breeding and genetic improvements for oil production.展开更多
In this paper, upon the pictographic theory and the behaviorist theory, based on Xiang's(2007) pictographic memorizing method, the author designs the corresponding procedure of the senior high school English vocab...In this paper, upon the pictographic theory and the behaviorist theory, based on Xiang's(2007) pictographic memorizing method, the author designs the corresponding procedure of the senior high school English vocabulary teaching. This research results show that, the application of the pictographic memorizing method in senior high school English vocabulary teaching is feasible and the teaching effect is relatively good.展开更多
This paper explores a special type of Chinese linguistic phenomenon used very popularly on the Internet,i.e.,the superposed Chinese sequence(SCS),such as又双叒叕as in我们又双叒叕要换首相了(we are going to have a new P...This paper explores a special type of Chinese linguistic phenomenon used very popularly on the Internet,i.e.,the superposed Chinese sequence(SCS),such as又双叒叕as in我们又双叒叕要换首相了(we are going to have a new Prime Minister ONCE AGAIN!).Different from emoticons or emojis,SCS uses normal Chinese characters,but these characters do not totally observe the phonetic,lexical,and syntactic rules in standard Chinese.While emphasizing the pictographic features of SCS,which are typical of Chinese,the correlation between SCS and the environment is explicated from the perspective of ecolinguistics.It is pointed out that many factors in the environment are affecting the creation and popularization of SCS.With the proposition of the classification of stable and dynamic factors,four major intermediate statuses are presented,which an examination of whether SCS might develop into a standard Chinese usage or just disappear when it gets out of date.展开更多
基金supported by the National Key R&D Program of China(Grant No.2017YFD0600703)the National Forestry Public Welfare Industry Research Project of China(Grant No.201204403)+2 种基金the Outstanding Youth Project of the Education Department of Hunan Province,China(Grant No.17B279)the US Department of AgricultureAgricultural Research Service(USDA-ARS)National Program for Quality and Utilization of Agricultural Products(NP 306Grant No.CRIS 6054-41000-103-00-D).
文摘Tung tree(Vernicia fordii) is an economically important woody oil plant that produces tung oil rich in eleostearic acid. Here, we report a high-quality chromosome-scale genome sequence of tung tree. The genome sequence was assembled by combining Illumina short reads, Pacific Biosciences single-molecule real-time long reads, and Hi-C sequencing data. The size of tung tree genome is 1.12 Gb, with 28,422 predicted genes and over 73% repeat sequences. The V. fordii underwent an ancient genome triplication event shared by core eudicots but no further wholegenome duplication in the subsequent ca. 34.55 million years of evolutionary history of the tung tree lineage. Insertion time analysis revealed that repeat-driven genome expansion might have arisen as a result of long-standing long terminal repeat retrotransposon bursts and lack of efficient DNA deletion mechanisms. The genome harbors 88 resistance genes encoding nucleotide-binding sites;17 of these genes may be involved in early-infection stage of Fusarium wilt resistance. Further, 651 oil-related genes were identified, 88 of which are predicted to be directly involved in tung oil biosynthesis. Relatively few phosphoenolpyruvate carboxykinase genes, and synergistic effects between transcription factors and oil biosynthesis-related genes might contribute to the high oil content of tung seed. The tung tree genome constitutes a valuable resource for understanding genome evolution, as well as for molecular breeding and genetic improvements for oil production.
文摘In this paper, upon the pictographic theory and the behaviorist theory, based on Xiang's(2007) pictographic memorizing method, the author designs the corresponding procedure of the senior high school English vocabulary teaching. This research results show that, the application of the pictographic memorizing method in senior high school English vocabulary teaching is feasible and the teaching effect is relatively good.
文摘This paper explores a special type of Chinese linguistic phenomenon used very popularly on the Internet,i.e.,the superposed Chinese sequence(SCS),such as又双叒叕as in我们又双叒叕要换首相了(we are going to have a new Prime Minister ONCE AGAIN!).Different from emoticons or emojis,SCS uses normal Chinese characters,but these characters do not totally observe the phonetic,lexical,and syntactic rules in standard Chinese.While emphasizing the pictographic features of SCS,which are typical of Chinese,the correlation between SCS and the environment is explicated from the perspective of ecolinguistics.It is pointed out that many factors in the environment are affecting the creation and popularization of SCS.With the proposition of the classification of stable and dynamic factors,four major intermediate statuses are presented,which an examination of whether SCS might develop into a standard Chinese usage or just disappear when it gets out of date.
