[Objectives]To compare the leaf morphology and leaf venation patterns of Hedyotis auricularia L.and its adulterants,such as Mitracarpus hirtus(L.)DC.,Spermacoce pusilla Wall.and Spermacoce alata Aubl.,produced in Guan...[Objectives]To compare the leaf morphology and leaf venation patterns of Hedyotis auricularia L.and its adulterants,such as Mitracarpus hirtus(L.)DC.,Spermacoce pusilla Wall.and Spermacoce alata Aubl.,produced in Guangxi,so as to provide a simple and rapid identification method for the identification of H.auricularia L.in Guangxi.[Methods]LMVP(leaf morphology-venation pattern)identification method was used to study the characteristics of leaf morphology-venation pattern.[Results]Characteristics of leaf morphology-venation pattern:(i)H.auricularia L.:circular knotted-curved pinnate leaf venation without reaching the margin;the primary veins run straight without branches,the number of secondary veins is 5 to 9,and the angles included in tertiary veins are mostly near right angles or obtuse angles.(ii)M.hirtus(L.)DC.:curved pinnate leaf venation without reaching the margin;the primary veins run straight without obvious changes,the number of secondary veins is 3 to 5,and the tertiary veins are slender,and the included angles are mostly acute.(iii)S.pusilla Wall.:curved leaf venation without reaching the leaf margin;there are 4 to 5 pairs of secondary veins,most of which are opposite;the angle between the secondary veins and the primary veins in the middle and near the petiole is mostly medium acute angle,and the extension of the tertiary veins has no fixed direction.(iv)S.alata Aubl.:circular knotted-curved pinnate leaf venation;the primary veins are convex and straight without branches,and there are 4 to 6 pairs of secondary veins,alternating.The angle between secondary veins and primary veins is mostly medium acute angle,the angle between tertiary veins and secondary veins is near right angle,and the tertiary veins are mostly transversely extended.[Conclusions]The leaf morphology-venation patterns of the above-mentioned H.auricularia L.and M.hirtus(L.)DC.,S.pusilla Wall.,and S.alata Aubl.can be used as their identification features,and the identification method has certain operability,which provides an identification idea for the identification of Chinese herbal medicines.展开更多
Mitogen-activated protein kinase （MAPK） cascades are universal signal transduction modules present in all eukaryotes. In plants, MAPK cascades were shown to regulate cell division, developmental processes, stress re...Mitogen-activated protein kinase （MAPK） cascades are universal signal transduction modules present in all eukaryotes. In plants, MAPK cascades were shown to regulate cell division, developmental processes, stress responses, and hormone pathways. The subgroup A of Arabidopsis MAPKs consists of AtMPK3, AtMPK6, and AtMPK10. AtMPK3 and AtMPK6 are activated by their upstream MAP kinase kinases （MKKs） AtMKK4 and AtMKK5 in response to biotic and abiotic stress. In addition, they were identified as key regulators of stomatal development and patterning. AtMPKIO has long been considered as a pseudo-gene, derived from a gene duplication of AtMPK6. Here we show that AtMPKIO is expressed highly but very transiently in seedlings and at sites of local auxin maxima leaves. MPK10 encodes a functional kinase and interacts with the upstream MAP kinase kinase （MAPKK） AtMKK2. mpklO mutants are delayed in flowering in long-day conditions and in continuous light. Moreover, cotyledons of mpk10 and mkk2 mutants have reduced vein complexity, which can be reversed by inhibiting polar auxin transport （PAT）. Auxin does not affect AtMPKIO expression while treatment with the PAT inhibitor HFCA extends the expression in leaves and reverses the mpklO mutant phenotype. These results suggest that the AtMKK2-AtMPK10 MAPK module regulates venation complexity by altering PAT efficiency.展开更多
Aiming at exploring the excellent structural performance of the vein-stiffening membrane structure of dragonfly hind wings,we analyzed two planar computational models and three 3D computational models with cambered co...Aiming at exploring the excellent structural performance of the vein-stiffening membrane structure of dragonfly hind wings,we analyzed two planar computational models and three 3D computational models with cambered corrugation based on the finite element method.It is shown that the vein size in different zones is proportional to the magnitude of the vein internal force when the wing structure is subjected to uniform out-of-plane transverse loading.The membrane contributes little to the flexural stiffness of the planar wing models,while exerting an immense impact upon the stiffness of the 3D wing models with cambered corrugation.If a lumped mass of 10% of the wing is fixed on the leading edge close to the wing tip,the wing fundamental fre-quency decreases by 10.7%～13.2%;if a lumped mass is connected to the wing via multiple springs,the wing fundamental fre-quency decreases by 16.0%～18.0%.Such decrease in fundamental frequency explains the special function of the wing pterostigma in alleviating the wing quivering effect.These particular features of dragonfly wings can be mimicked in the design of new-style reticulately stiffening thin-walled roof systems and flapping wings in novel intelligent aerial vehicles.展开更多
Plants produce a rich diversity of biological forms,and the diversity of leaves is especially notable.Mechanisms of leaf morphogenesis have been studied in the past two decades,with a growing focus on the interactive ...Plants produce a rich diversity of biological forms,and the diversity of leaves is especially notable.Mechanisms of leaf morphogenesis have been studied in the past two decades,with a growing focus on the interactive roles of mechanics in recent years.Growth of plant organs involves feedback by mechanical stress:growth induces stress,and stress affects growth and morphogenesis.Although much attention has been given to potential stress-sensing mechanisms and cellular responses,the mechanical principles guiding morphogenesis have not been well understood.Here we synthesize the overarching roles of mechanics and mechanical stress in multilevel and multiple stages of leaf morphogenesis,encompassing leaf primordium initiation,phyllotaxis and venation patterning,and the establishment of complex mature leaf shapes.Moreover,the roles of mechanics at multiscale levels,from subcellular cytoskeletal molecules to single cells to tissues at the organ scale,are articulated.By highlighting the role of mechanical buckling in the formation of three-dimensional leaf shapes,this review integrates the perspectives of mechanics and biology to provide broader insights into the mechanobiology of leaf morphogenesis.展开更多
基金Supported by Guangxi Key Laboratory of Zhuang and Yao Medicine(GuiKeJiZi 201432)Zhuang and Yao Medicine Collaborative Innovation Center(GuiJiaoKeYan 201320)+3 种基金Guangxi Young Talent Project of Guangxi University of Chinese Medicine(2022C030)Ethnic Medicine Resources and Application Engineering Research Center in Guangxi Zhuang Autonomous Region(GuiFaGaiGaoJiHan 20202605)Key Discipline Project of Traditional Chinese Medicine in Guangxi—Zhuang Medicine(GZXK-Z-20-64)Guangxi First-class Discipline of Traditional Chinese Medicine—Ethnopharmacology(GuiJiaoKeYan 201812).
文摘[Objectives]To compare the leaf morphology and leaf venation patterns of Hedyotis auricularia L.and its adulterants,such as Mitracarpus hirtus(L.)DC.,Spermacoce pusilla Wall.and Spermacoce alata Aubl.,produced in Guangxi,so as to provide a simple and rapid identification method for the identification of H.auricularia L.in Guangxi.[Methods]LMVP(leaf morphology-venation pattern)identification method was used to study the characteristics of leaf morphology-venation pattern.[Results]Characteristics of leaf morphology-venation pattern:(i)H.auricularia L.:circular knotted-curved pinnate leaf venation without reaching the margin;the primary veins run straight without branches,the number of secondary veins is 5 to 9,and the angles included in tertiary veins are mostly near right angles or obtuse angles.(ii)M.hirtus(L.)DC.:curved pinnate leaf venation without reaching the margin;the primary veins run straight without obvious changes,the number of secondary veins is 3 to 5,and the tertiary veins are slender,and the included angles are mostly acute.(iii)S.pusilla Wall.:curved leaf venation without reaching the leaf margin;there are 4 to 5 pairs of secondary veins,most of which are opposite;the angle between the secondary veins and the primary veins in the middle and near the petiole is mostly medium acute angle,and the extension of the tertiary veins has no fixed direction.(iv)S.alata Aubl.:circular knotted-curved pinnate leaf venation;the primary veins are convex and straight without branches,and there are 4 to 6 pairs of secondary veins,alternating.The angle between secondary veins and primary veins is mostly medium acute angle,the angle between tertiary veins and secondary veins is near right angle,and the tertiary veins are mostly transversely extended.[Conclusions]The leaf morphology-venation patterns of the above-mentioned H.auricularia L.and M.hirtus(L.)DC.,S.pusilla Wall.,and S.alata Aubl.can be used as their identification features,and the identification method has certain operability,which provides an identification idea for the identification of Chinese herbal medicines.
文摘Mitogen-activated protein kinase （MAPK） cascades are universal signal transduction modules present in all eukaryotes. In plants, MAPK cascades were shown to regulate cell division, developmental processes, stress responses, and hormone pathways. The subgroup A of Arabidopsis MAPKs consists of AtMPK3, AtMPK6, and AtMPK10. AtMPK3 and AtMPK6 are activated by their upstream MAP kinase kinases （MKKs） AtMKK4 and AtMKK5 in response to biotic and abiotic stress. In addition, they were identified as key regulators of stomatal development and patterning. AtMPKIO has long been considered as a pseudo-gene, derived from a gene duplication of AtMPK6. Here we show that AtMPKIO is expressed highly but very transiently in seedlings and at sites of local auxin maxima leaves. MPK10 encodes a functional kinase and interacts with the upstream MAP kinase kinase （MAPKK） AtMKK2. mpklO mutants are delayed in flowering in long-day conditions and in continuous light. Moreover, cotyledons of mpk10 and mkk2 mutants have reduced vein complexity, which can be reversed by inhibiting polar auxin transport （PAT）. Auxin does not affect AtMPKIO expression while treatment with the PAT inhibitor HFCA extends the expression in leaves and reverses the mpklO mutant phenotype. These results suggest that the AtMKK2-AtMPK10 MAPK module regulates venation complexity by altering PAT efficiency.
基金Project supported by the National Natural Science Foundation of China(No. 50408022)the Visiting Scholarship from the Future Academic Star Project of Zhejiang Universitythe Scientific Research Foundation for the Returned Overseas Chinese Scholars,MOE and Zhejiang Province,China
文摘Aiming at exploring the excellent structural performance of the vein-stiffening membrane structure of dragonfly hind wings,we analyzed two planar computational models and three 3D computational models with cambered corrugation based on the finite element method.It is shown that the vein size in different zones is proportional to the magnitude of the vein internal force when the wing structure is subjected to uniform out-of-plane transverse loading.The membrane contributes little to the flexural stiffness of the planar wing models,while exerting an immense impact upon the stiffness of the 3D wing models with cambered corrugation.If a lumped mass of 10% of the wing is fixed on the leading edge close to the wing tip,the wing fundamental fre-quency decreases by 10.7%～13.2%;if a lumped mass is connected to the wing via multiple springs,the wing fundamental fre-quency decreases by 16.0%～18.0%.Such decrease in fundamental frequency explains the special function of the wing pterostigma in alleviating the wing quivering effect.These particular features of dragonfly wings can be mimicked in the design of new-style reticulately stiffening thin-walled roof systems and flapping wings in novel intelligent aerial vehicles.
基金support from Nanyang Technological University(grant no.M4082428)K.J.H.and C.H.acknowledge support from Nanyang Technological University under its Accelerating Creativity and Excellence(ACE)grant(grant no.NTU-ACE2020-07)+2 种基金supported by the Center for Engineering Mechano Biology,an National Science Foundation(NSF)Science and Technology Center,under grant agreement No.CMMI:15-48571supported by the U.S.Department of Energy(grant no.DE-FG2-84ER13179)support from the Ministry of Education-Singapore,under its Academic Research Fund Tier 1(RT11/20 and RG32/20).
文摘Plants produce a rich diversity of biological forms,and the diversity of leaves is especially notable.Mechanisms of leaf morphogenesis have been studied in the past two decades,with a growing focus on the interactive roles of mechanics in recent years.Growth of plant organs involves feedback by mechanical stress:growth induces stress,and stress affects growth and morphogenesis.Although much attention has been given to potential stress-sensing mechanisms and cellular responses,the mechanical principles guiding morphogenesis have not been well understood.Here we synthesize the overarching roles of mechanics and mechanical stress in multilevel and multiple stages of leaf morphogenesis,encompassing leaf primordium initiation,phyllotaxis and venation patterning,and the establishment of complex mature leaf shapes.Moreover,the roles of mechanics at multiscale levels,from subcellular cytoskeletal molecules to single cells to tissues at the organ scale,are articulated.By highlighting the role of mechanical buckling in the formation of three-dimensional leaf shapes,this review integrates the perspectives of mechanics and biology to provide broader insights into the mechanobiology of leaf morphogenesis.
