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
Leaf curvature significantly contributes to important economic traits in vegetable crops.The upward-curling leaf phenotype has been consistently observed upon overexpression of a miR156/157-resistant version of the SQ...Leaf curvature significantly contributes to important economic traits in vegetable crops.The upward-curling leaf phenotype has been consistently observed upon overexpression of a miR156/157-resistant version of the SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 10(SPL10)transcription factor(rSPL10).However,the role of SPL10 in regulating leaf curvature has not been well characterized.In this study,using DNA affinity purification sequencing followed by transient transactivation assays,we found that SPL10 can bind to the promoter and gene body of REVOLUTA(REV),augmenting its expression.The rSPL10 rev-6 double mutant plant displayed a downward-curling leaf phenotype similar to the rev-6 plant,supporting the notion that REV functions downstream of SPL10.Importantly,the SPL10 protein physically interacts with the REV protein,which attenuates the expression of REV promoted by SPL10,leading to the downregulation of REV-regulated genes involved in leaf curvature,such as HB2 and HB4.These findings suggest that the SPL10–REV module acts as a molecular rheostat to prevent excessive amplification of REV transcripts in Arabidopsis.Furthermore,overexpression of the BrpREV1 gene in Chinese cabbage caused the transformation of rosette leaves from flat to upward-curving and accelerated heading.Taken together,our findings reveal the role of SPL10–REV module in orchestrating leaf curvature,which could potentially be utilized for molecular breeding of economical traits in vegetable crops.展开更多
The curd of cauliflower(Brassica oleracea L.var.botrytis)is a modified inflorescence that is consumed as a vegetable.Curd formation is proposed to be due to a mutation in the BobCAULIFLOWER(BobCAL)gene,but the genetic...The curd of cauliflower(Brassica oleracea L.var.botrytis)is a modified inflorescence that is consumed as a vegetable.Curd formation is proposed to be due to a mutation in the BobCAULIFLOWER(BobCAL)gene,but the genetic relationship between BobCAL variation and curd morphotypes remains obscure.To address this question,we collected and classified a collection of 78 cauliflower accessions into four subpopulations according to curd surface features:smooth,coarse,granular,and hairy curd morphotypes.Through the cDNA sequencing of BobCAL alleles,we showed that smooth and coarse accessions characterized by inflorescence meristem arrest presented a strong association with the 451T SNP(BobCAL_T),whereas granular and hairy accessions marked with floral organ arrest presented an association with 451G(BobCAL_G).Interestingly,all BobCAL alleles were alternatively spliced,resulting in a total of four alternative splice(AS)variants due to the retention of the fourth and/or seventh introns.Among accessions with BobCAL_G alleles,the total expression of all these AS variants in granular plants was almost equal to that in hairy plants;however,the expression of the individual AS variants encoding intact proteins relative to those encoding truncated proteins differed.Hairy accessions showed relatively high expression of the individual variants encoding intact proteins,whereas granular accessions displayed relatively low expression.In smooth cauliflower,the overexpression of the BobCAL_Ga variant caused an alteration in the curd morphotype from smooth to hairy,concurrent with an increase in the expression levels of downstream floral identity genes.These results reveal that alternative splicing of BobCAL transcripts is involved in the determination of cauliflower curd morphotypes.展开更多
In this paper,we consider the following Schrodinger-Poisson system{-ε^(2)Δu+V(x)u+K(x)Φ(x)u=|u|^(p-1)u in R^(N),-ΔΦ(x)=K(x)u^(2)in RN,,where e is a small parameter,1<p<N+2/N-2,N∈[3,6],and V(x)and K(x)are p...In this paper,we consider the following Schrodinger-Poisson system{-ε^(2)Δu+V(x)u+K(x)Φ(x)u=|u|^(p-1)u in R^(N),-ΔΦ(x)=K(x)u^(2)in RN,,where e is a small parameter,1<p<N+2/N-2,N∈[3,6],and V(x)and K(x)are potential functions with different decay at infinity.We first prove the non-degeneracy of a radial low-energy solution.Moreover,by using the non-degenerate solution,we construct a new type of infinitely many solutions for the above system,which are called“dichotomous solutions”,i.e.,these solutions concentrate both in a bounded domain and near infinity.展开更多
Natural killer （NK） cell education, a process for achieving functional maturation and self-tolerance, has been previously defined by the interaction between self-major histocompatibility complex class I （MHC-I） mo...Natural killer （NK） cell education, a process for achieving functional maturation and self-tolerance, has been previously defined by the interaction between self-major histocompatibility complex class I （MHC-I） molecules and their specific inhibitory receptors. Over the past several years, growing evidence has highlighted the important roles of nonclassical MHC-I and non-MHC-I molecules in NK cell education. Herein, we review the current knowledge of NK cell education, with a particular focus on nonclassical MHC-I- and non-MHC-I-dependent education, and compare them with the classical MHC-I-dependent education theory. In addition, we update and extend this theory by presenting the ＇Confining Model＇, discussing cis and trans characteristics, reassessing quantity and quality control, and elucidating the redundancy of NK cell education in tumor and virus infection.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.
基金supported by the National Natural Science Foundation of China(Grant Nos.32170581 and 32370587 to X.Y.,No.32272043 and No.32472190 to S.L.)China Postdoctoral Science Foundation(2022M72211 to P.X.)this research is funded by the Hong Kong Scholars Program.
文摘Leaf curvature significantly contributes to important economic traits in vegetable crops.The upward-curling leaf phenotype has been consistently observed upon overexpression of a miR156/157-resistant version of the SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 10(SPL10)transcription factor(rSPL10).However,the role of SPL10 in regulating leaf curvature has not been well characterized.In this study,using DNA affinity purification sequencing followed by transient transactivation assays,we found that SPL10 can bind to the promoter and gene body of REVOLUTA(REV),augmenting its expression.The rSPL10 rev-6 double mutant plant displayed a downward-curling leaf phenotype similar to the rev-6 plant,supporting the notion that REV functions downstream of SPL10.Importantly,the SPL10 protein physically interacts with the REV protein,which attenuates the expression of REV promoted by SPL10,leading to the downregulation of REV-regulated genes involved in leaf curvature,such as HB2 and HB4.These findings suggest that the SPL10–REV module acts as a molecular rheostat to prevent excessive amplification of REV transcripts in Arabidopsis.Furthermore,overexpression of the BrpREV1 gene in Chinese cabbage caused the transformation of rosette leaves from flat to upward-curving and accelerated heading.Taken together,our findings reveal the role of SPL10–REV module in orchestrating leaf curvature,which could potentially be utilized for molecular breeding of economical traits in vegetable crops.
基金supported by the National Programs for Science and Technology Development of China(Grant Nos.2016YFD0101900 and 2016YFD100500)the Natural Science Foundation of China(Grant No.31571261)the Shanghai Agriculture Applied Technology Development Program,China(Grant Nos.G2015060107 and Z20160109).
文摘The curd of cauliflower(Brassica oleracea L.var.botrytis)is a modified inflorescence that is consumed as a vegetable.Curd formation is proposed to be due to a mutation in the BobCAULIFLOWER(BobCAL)gene,but the genetic relationship between BobCAL variation and curd morphotypes remains obscure.To address this question,we collected and classified a collection of 78 cauliflower accessions into four subpopulations according to curd surface features:smooth,coarse,granular,and hairy curd morphotypes.Through the cDNA sequencing of BobCAL alleles,we showed that smooth and coarse accessions characterized by inflorescence meristem arrest presented a strong association with the 451T SNP(BobCAL_T),whereas granular and hairy accessions marked with floral organ arrest presented an association with 451G(BobCAL_G).Interestingly,all BobCAL alleles were alternatively spliced,resulting in a total of four alternative splice(AS)variants due to the retention of the fourth and/or seventh introns.Among accessions with BobCAL_G alleles,the total expression of all these AS variants in granular plants was almost equal to that in hairy plants;however,the expression of the individual AS variants encoding intact proteins relative to those encoding truncated proteins differed.Hairy accessions showed relatively high expression of the individual variants encoding intact proteins,whereas granular accessions displayed relatively low expression.In smooth cauliflower,the overexpression of the BobCAL_Ga variant caused an alteration in the curd morphotype from smooth to hairy,concurrent with an increase in the expression levels of downstream floral identity genes.These results reveal that alternative splicing of BobCAL transcripts is involved in the determination of cauliflower curd morphotypes.
基金supported by National Natural Science Foundation of China(Grant Nos.12101274 and 12226309)the Jiangxi Province Science Fund for Distinguished Young Scholars(Grant No.20224ACB218001)+3 种基金supported by National Natural Science Foundation of China(Grant No.12271223)Jiangxi Provincial Natural Science Foundation(Grant No.20212ACB201003)Jiangxi Two Thousand Talents Program(Grant No.jxsq2019101001)Double-high Talents Program in Jiangxi Province。
文摘In this paper,we consider the following Schrodinger-Poisson system{-ε^(2)Δu+V(x)u+K(x)Φ(x)u=|u|^(p-1)u in R^(N),-ΔΦ(x)=K(x)u^(2)in RN,,where e is a small parameter,1<p<N+2/N-2,N∈[3,6],and V(x)and K(x)are potential functions with different decay at infinity.We first prove the non-degeneracy of a radial low-energy solution.Moreover,by using the non-degenerate solution,we construct a new type of infinitely many solutions for the above system,which are called“dichotomous solutions”,i.e.,these solutions concentrate both in a bounded domain and near infinity.
基金This work was supported by the Ministry of Science ＆ Technology of China （973 Basic Science Project） #2013CB944902 （ZT）, Natural Science Foundation of China #81361120388 and #31390433 （ZT）, and Key Program of the Chinese Academy of Sciences （KJZD-EW-L10 -003） （RS, ZT）.
文摘Natural killer （NK） cell education, a process for achieving functional maturation and self-tolerance, has been previously defined by the interaction between self-major histocompatibility complex class I （MHC-I） molecules and their specific inhibitory receptors. Over the past several years, growing evidence has highlighted the important roles of nonclassical MHC-I and non-MHC-I molecules in NK cell education. Herein, we review the current knowledge of NK cell education, with a particular focus on nonclassical MHC-I- and non-MHC-I-dependent education, and compare them with the classical MHC-I-dependent education theory. In addition, we update and extend this theory by presenting the ＇Confining Model＇, discussing cis and trans characteristics, reassessing quantity and quality control, and elucidating the redundancy of NK cell education in tumor and virus infection.
