Development and differentiation is an important and leading research field in modern biology. Streptomyces has a complicated life cycle of morphological differentiation including the spore germination, aerial mycelium...Development and differentiation is an important and leading research field in modern biology. Streptomyces has a complicated life cycle of morphological differentiation including the spore germination, aerial mycelium and spore formation. Each developmental stage has a distinguished morphological feature which greatly facilitates the identification of developmental mutants, the complementary cloning and the spatial and temporal expression of the genes involved in differentiation. This characteristic of Streptomyces is comparatively superior to other pro-karyotic bacteria such as Escherichia coli, Bacillus sub-tilis and Myxococcus xanthus. Moreover, Streptomyces also possesses a complicated physiological differentiation in which it produces a wide variety of secondary metabolites (more than half of the 12 000 or so known antibiotics), including many important antibiotics used in medi-展开更多
BELl-like transcription factors are ubiquitous in plants and interact with KNOTTEDI-types to regulate numerous developmental processes. In potato, the RNA of several BELl-like transcription factors has been identified...BELl-like transcription factors are ubiquitous in plants and interact with KNOTTEDI-types to regulate numerous developmental processes. In potato, the RNA of several BELl-like transcription factors has been identified in phloem cells. One of these, StBEL5, and its Knox protein partner regulate tuber formation by targeting genes that control growth. RNA detection methods and grafting experiments demonstrated that StBEL5 transcripts move across a graft union to localize in stolon tips, the site of tuber induction. This movement of RNA originates in source leaf veins and petioles and is induced by a short-day photoperiod, regulated by the untranslated regions, and correlated with enhanced tuber production. Addition of the StBEL5 untranslated regions to another BELl.like mRNA resulted in its preferential transport to stolon tips leading to increased tuber production. Upon fusion of the untranslated regions of StBEL5 to a β-glucuronidase marker, translation in tobacco protoplasts was repressed by those constructs containing the 3' untranslated sequence. The untranslated regions of the StBEL5 mRNA are involved in mediating its long-distance transport and in controlling translation. The 3' untranslated sequence contains an abundance of conserved motifs that may serve as binding motifs for RNA-binding proteins. Because of their presence in the phloem sieve tube system, their unique untranslated region sequences and their diverse RNA accumulation patterns, the family of BEL1-like RNAs from potato represents a valuable model for studying the long-distance transport of full-length mRNAs and their role in development.展开更多
基金This work was supported by the National Natural Science Foundation of China (Grant No. 39830010) the National Outstanding Youth Foundation of China (Grant No. 39925002)and the State Key Laboratory of Microbial Resources of China.
文摘Development and differentiation is an important and leading research field in modern biology. Streptomyces has a complicated life cycle of morphological differentiation including the spore germination, aerial mycelium and spore formation. Each developmental stage has a distinguished morphological feature which greatly facilitates the identification of developmental mutants, the complementary cloning and the spatial and temporal expression of the genes involved in differentiation. This characteristic of Streptomyces is comparatively superior to other pro-karyotic bacteria such as Escherichia coli, Bacillus sub-tilis and Myxococcus xanthus. Moreover, Streptomyces also possesses a complicated physiological differentiation in which it produces a wide variety of secondary metabolites (more than half of the 12 000 or so known antibiotics), including many important antibiotics used in medi-
基金supported by the United States Departmentof Agriculture NRI-CGP award no.2008-02806National Science Foundation-Plant Genome Research Program award no.0820659
文摘BELl-like transcription factors are ubiquitous in plants and interact with KNOTTEDI-types to regulate numerous developmental processes. In potato, the RNA of several BELl-like transcription factors has been identified in phloem cells. One of these, StBEL5, and its Knox protein partner regulate tuber formation by targeting genes that control growth. RNA detection methods and grafting experiments demonstrated that StBEL5 transcripts move across a graft union to localize in stolon tips, the site of tuber induction. This movement of RNA originates in source leaf veins and petioles and is induced by a short-day photoperiod, regulated by the untranslated regions, and correlated with enhanced tuber production. Addition of the StBEL5 untranslated regions to another BELl.like mRNA resulted in its preferential transport to stolon tips leading to increased tuber production. Upon fusion of the untranslated regions of StBEL5 to a β-glucuronidase marker, translation in tobacco protoplasts was repressed by those constructs containing the 3' untranslated sequence. The untranslated regions of the StBEL5 mRNA are involved in mediating its long-distance transport and in controlling translation. The 3' untranslated sequence contains an abundance of conserved motifs that may serve as binding motifs for RNA-binding proteins. Because of their presence in the phloem sieve tube system, their unique untranslated region sequences and their diverse RNA accumulation patterns, the family of BEL1-like RNAs from potato represents a valuable model for studying the long-distance transport of full-length mRNAs and their role in development.