HYL1(HYPONASTIC LEAVES 1)in Arabidopsis thaliana encodes a double-stranded RNA-binding protein needed for proper miRNA maturation,and its null mutant hyl1 shows a typical leaf-incurvature phenotype.In Chinese cabbage,...HYL1(HYPONASTIC LEAVES 1)in Arabidopsis thaliana encodes a double-stranded RNA-binding protein needed for proper miRNA maturation,and its null mutant hyl1 shows a typical leaf-incurvature phenotype.In Chinese cabbage,BcpLH(Brassica rapa ssp.pekinensis LEAFY HEADS),a close homolog of HYL1,is differentially expressed in juvenile leaves,which are flat,and in adult leaves,which display extreme incurvature.BcpLH lacks protein–protein interaction domains and is much shorter than HYL1.To test whether BcpLH is associated with defects in microRNA(miRNA)biogenesis and leaf flatness,we enhanced and repressed the activity of BcpLH by transgenics and investigated BcpLH-dependent miRNAs and plant morphology.BcpLH promoted miRNA biogenesis by the proper processing of primary miRNAs.BcpLH downregulation via antisense decreased a specific subset of miRNAs and increased the activities of their target genes,causing upward curvature of rosette leaves and early leaf incurvature,concurrent with the enlargement,earliness,and round-to-oval shape transition of leafy heads.Moreover,BcpLH-dependent miRNAs in Chinese cabbage are not the same as HYL1-dependent miRNAs in Arabidopsis.We suggest that BcpLH controls a specific subset of miRNAs in Chinese cabbage and coordinates the direction,extent,and timing of leaf curvature during head formation in Brassica rapa.展开更多
MicroRNAs (miRNAs) are a class of 20- to 24-nt noncoding RNAs that function as important regulators of plant development and stress responses. Most 21-nt miRNAs direct the cleavage of complementary target mRNAs or inh...MicroRNAs (miRNAs) are a class of 20- to 24-nt noncoding RNAs that function as important regulators of plant development and stress responses. Most 21-nt miRNAs direct the cleavage of complementary target mRNAs or inhibit their translation, while some 22-nt miRNAs not only cleave target mRNAs but also trigger the bioge nesis of sec on dary small in terfering RNAs (siRNAs) to further repress target mRNAs.展开更多
Medicinal plants produce a myriad of health-promoting natural products and have been widely used for thousands of years in traditional medical practices,especially in ancient Asia and Af- rica.However,although a large...Medicinal plants produce a myriad of health-promoting natural products and have been widely used for thousands of years in traditional medical practices,especially in ancient Asia and Af- rica.However,although a large number of natural products have been isolated and identified from plants by modern chemical and metabolomic methods,there is still a huge gap in understanding the nature of medicinal plant ingredients and the genetic basis of their biosynthesis.展开更多
基金supported by grants from the National Key Research and Development Program of China(Grant No.2016YFD0101900,2016YFD0100500)the Natural Science Foundation of China(Grant Nos.31771442 and 31571261).
文摘HYL1(HYPONASTIC LEAVES 1)in Arabidopsis thaliana encodes a double-stranded RNA-binding protein needed for proper miRNA maturation,and its null mutant hyl1 shows a typical leaf-incurvature phenotype.In Chinese cabbage,BcpLH(Brassica rapa ssp.pekinensis LEAFY HEADS),a close homolog of HYL1,is differentially expressed in juvenile leaves,which are flat,and in adult leaves,which display extreme incurvature.BcpLH lacks protein–protein interaction domains and is much shorter than HYL1.To test whether BcpLH is associated with defects in microRNA(miRNA)biogenesis and leaf flatness,we enhanced and repressed the activity of BcpLH by transgenics and investigated BcpLH-dependent miRNAs and plant morphology.BcpLH promoted miRNA biogenesis by the proper processing of primary miRNAs.BcpLH downregulation via antisense decreased a specific subset of miRNAs and increased the activities of their target genes,causing upward curvature of rosette leaves and early leaf incurvature,concurrent with the enlargement,earliness,and round-to-oval shape transition of leafy heads.Moreover,BcpLH-dependent miRNAs in Chinese cabbage are not the same as HYL1-dependent miRNAs in Arabidopsis.We suggest that BcpLH controls a specific subset of miRNAs in Chinese cabbage and coordinates the direction,extent,and timing of leaf curvature during head formation in Brassica rapa.
文摘MicroRNAs (miRNAs) are a class of 20- to 24-nt noncoding RNAs that function as important regulators of plant development and stress responses. Most 21-nt miRNAs direct the cleavage of complementary target mRNAs or inhibit their translation, while some 22-nt miRNAs not only cleave target mRNAs but also trigger the bioge nesis of sec on dary small in terfering RNAs (siRNAs) to further repress target mRNAs.
文摘Medicinal plants produce a myriad of health-promoting natural products and have been widely used for thousands of years in traditional medical practices,especially in ancient Asia and Af- rica.However,although a large number of natural products have been isolated and identified from plants by modern chemical and metabolomic methods,there is still a huge gap in understanding the nature of medicinal plant ingredients and the genetic basis of their biosynthesis.
