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Timothy J Brodribb - One of the best experts on this subject based on the ideXlab platform.

  • Water Transport, the Role in Plant Diversification of
    Encyclopedia of Evolutionary Biology, 2016
    Co-Authors: Jarmila Pittermann, J.p. Wilson, Timothy J Brodribb
    Abstract:

    Efficient water transport is paramount to the success of land plants. The evolution of xylem tissue was driven in part by the requirement to move water efficiently from roots to shoots, and by the need to withstand drought and freezing stress, which may block water transport by filling conduits with air. This review explores the links between xylem traits and the diversification of select plant groups, highlighting Devonian experiments in water transport, the Cretaceous evolution of high Leaf Vein density, and the challenges that Cenozoic climates and angiosperm competition imposed on water transport in conifers and ferns.

  • the influence of branch order on optimal Leaf Vein geometries murray s law and area preserving branching
    PLOS ONE, 2013
    Co-Authors: Charles A. Price, Sarahjane C Knox, Timothy J Brodribb
    Abstract:

    Models that predict the form of hierarchical branching networks typically invoke optimization based on biomechanical similitude, the minimization of impedance to fluid flow, or construction costs. Unfortunately, due to the small size and high number of Vein segments found in real biological networks, complete descriptions of networks needed to evaluate such models are rare. To help address this we report results from the analysis of the branching geometry of 349 Leaf Vein networks comprising over 1.5 million individual Vein segments. In addition to measuring the diameters of individual Veins before and after Vein bifurcations, we also assign Vein orders using the Horton-Strahler ordering algorithm adopted from the study of river networks. Our results demonstrate that across all leaves, both radius tapering and the ratio of daughter to parent branch areas for Leaf Veins are in strong agreement with the expectation from Murray’s law. However, as Veins become larger, area ratios shift systematically toward values expected under area-preserving branching. Our work supports the idea that Leaf Vein networks differentiate roles of Leaf support and hydraulic supply between hierarchical orders.

  • fossil evidence for cretaceous escalation in angiosperm Leaf Vein evolution
    Proceedings of the National Academy of Sciences of the United States of America, 2011
    Co-Authors: Taylor S. Feild, Andres Baresch, Barbara A R Mohr, Bernard Gomez, Ari Iglesias, Clement Coiffard, David S Chatelet, Timothy J Brodribb, Gilbert R Upchurch, Jiri Kvacek
    Abstract:

    The flowering plants that dominate modern vegetation possess Leaf gas exchange potentials that far exceed those of all other living or extinct plants. The great divide in maximal ability to exchange CO2 for water between leaves of nonangiosperms and angiosperms forms the mechanistic foundation for speculation about how angiosperms drove sweeping ecological and biogeochemical change during the Cretaceous. However, there is no empirical evidence that angiosperms evolved highly photosynthetically active leaves during the Cretaceous. Using Vein density (DV) measurements of fossil angiosperm leaves, we show that the Leaf hydraulic capacities of angiosperms escalated several-fold during the Cretaceous. During the first 30 million years of angiosperm Leaf evolution, angiosperm leaves exhibited uniformly low Vein DV that overlapped the DV range of dominant Early Cretaceous ferns and gymnosperms. Fossil angiosperm Vein densities reveal a subsequent biphasic increase in DV. During the first mid-Cretaceous surge, angiosperm DV first surpassed the upper bound of DV limits for nonangiosperms. However, the upper limits of DV typical of modern megathermal rainforest trees first appear during a second wave of increased DV during the Cretaceous-Tertiary transition. Thus, our findings provide fossil evidence for the hypothesis that significant ecosystem change brought about by angiosperms lagged behind the Early Cretaceous taxonomic diversification of angiosperms.

  • Leaf hydraulic evolution led a surge in Leaf photosynthetic capacity during early angiosperm diversification
    Ecology Letters, 2010
    Co-Authors: Timothy J Brodribb, Taylor S. Feild
    Abstract:

    Angiosperm evolution transformed global ecology, and much of this impact derives from the unrivalled vegetative productivity of dominant angiosperm clades. However, the origins of high photosynthetic capacity in angiosperms remain unknown. In this study, we describe the steep trajectory of Leaf Vein density (Dv) evolution in angiosperms, and predict that this Leaf plumbing innovation enabled a major shift in the capacity of leaves to assimilate CO2. Reconstructing Leaf Vein evolution from an examination of 504 angiosperm species we found a rapid three- to fourfold increase in Dv occurred during the early evolution of angiosperms. We demonstrate how this major shift in Leaf Vein architecture potentially allowed the maximum photosynthetic capacity in angiosperms to rise above competing groups 140–100 Ma. Our data suggest that early terrestrial angiosperms produced leaves with low photosynthetic rates, but that subsequent angiosperm success is linked to a surge in photosynthetic capacity during their early diversification.

  • angiosperm Leaf Vein evolution was physiologically and environmentally transformative
    Proceedings of The Royal Society B: Biological Sciences, 2009
    Co-Authors: Kevin C Boyce, Taylor S. Feild, Timothy J Brodribb, Maciej A Zwieniecki
    Abstract:

    The Veins that irrigate leaves during photosynthesis are demonstrated to be strikingly more abundant in flowering plants than in any other vascular plant lineage. Angiosperm Vein densities average 8 mm of Vein per mm2 of Leaf area and can reach 25 mm mm−2, whereas such high densities are absent from all other plants, living or extinct. Leaves of non-angiosperms have consistently averaged close to 2 mm mm−2 throughout 380 million years of evolution despite a complex history that has involved four or more independent origins of laminate leaves with many Veins and dramatic changes in climate and atmospheric composition. We further demonstrate that the high Leaf Vein densities unique to the angiosperms enable unparalleled transpiration rates, extending previous work indicating a strong correlation between Vein density and assimilation rates. Because Vein density is directly measurable in fossils, these correlations provide new access to the physiology of extinct plants and how they may have impacted their environments. First, the high assimilation rates currently confined to the angiosperms among living plants are likely to have been unique throughout evolutionary history. Second, the transpiration-driven recycling of water that is important for bolstering precipitation in modern tropical rainforests might have been significantly less in a world before the angiosperms.

Jim Mattsson - One of the best experts on this subject based on the ideXlab platform.

  • Identification of Auxin Response Factor-Encoding Genes Expressed in Distinct Phases of Leaf Vein Development and with Overlapping Functions in Leaf Formation.
    Plants (Basel Switzerland), 2019
    Co-Authors: Mathias Schuetz, Mario Fidanza, Jim Mattsson
    Abstract:

    Based on mutant phenotypes the MONOPTEROS (MP)/Auxin Response Factor 5 (ARF5) gene acts in several developmental processes including Leaf Vein development. Since overlapping functions among ARF genes are common, we assessed the related ARF 3-8 and 19 genes for potential overlap in expression during Vein development using in-situ hybridization. Like MP/ARF5, ARF3 was expressed in preprocambial and procambial cells. ARF7 was also expressed in procambial cells, close to and during Vein differentiation. ARF19 was expressed in differentiating vessel elements. To assess if genes with Vein expression have overlapping functions, double mutants were generated. While arf3, 5 and 7 mutants formed leaves normally, double mutant combinations of mp/arf5 with arf3 or arf7 resulted in a breakdown of Leaf formation. Instead, novel structures not present in any of the single mutants formed. The results implicate ARF3 and ARF7 in rosette Leaf formation and suggest that their functions overlap and act in parallel with MP/ARF5 in this process. The observed vascular expression patterns suggest unique functions (ARF7 and 19) and potentially overlapping functions (ARF3 and 5) in Vein development. Since arf3 arf5 double mutants do not form leaves, assessment of their potential combined action in Vein development will require the use of conditional mutants.

  • short internodes stylish genes regulators of auxin biosynthesis are involved in Leaf Vein development in arabidopsis thaliana
    New Phytologist, 2013
    Co-Authors: Tammy Baylis, Izabela Cierlik, Eva Sundberg, Jim Mattsson
    Abstract:

    Leaves depend on highly developed venation systems to collect fixed carbon for transport and to distribute water. We hypothesized that local regulation of auxin biosynthesis plays a role in Vein development. To this effect, we assessed the role of the SHORT INTERNODES/STYLISH (SHI/STY) gene family, zinc-finger transcription factors linked to regulation of auxin biosynthesis, in Arabidopsis thaliana Leaf Vein development. Gene functions were assessed by a combination of high-resolution spatio-temporal expression analysis of promoter-marker lines and phenotypic analysis of plants homozygous for single and multiple mutant combinations. The SHI/STY genes showed expression patterns with variations on a common theme of activity in incipient and developing cotyledon and Leaf primordia, narrowing to apices and hydathode regions. Mutant analysis of single to quintuple mutant combinations revealed dose-dependent defects in Vein patterning affecting multiple Vein traits, most notably in cotyledons. Here we demonstrate that local regulation of auxin biosynthesis is an important aspect of Leaf Vein development. Our findings also support a model in which auxin synthesized at the periphery of primordia affects Vein development.

  • SHORT INTERNODES/STYLISH genes, regulators of auxin biosynthesis, are involved in Leaf Vein development in Arabidopsis thaliana.
    The New phytologist, 2013
    Co-Authors: Tammy Baylis, Izabela Cierlik, Eva Sundberg, Jim Mattsson
    Abstract:

    Leaves depend on highly developed venation systems to collect fixed carbon for transport and to distribute water. We hypothesized that local regulation of auxin biosynthesis plays a role in Vein development. To this effect, we assessed the role of the SHORT INTERNODES/STYLISH (SHI/STY) gene family, zinc-finger transcription factors linked to regulation of auxin biosynthesis, in Arabidopsis thaliana Leaf Vein development. Gene functions were assessed by a combination of high-resolution spatio-temporal expression analysis of promoter-marker lines and phenotypic analysis of plants homozygous for single and multiple mutant combinations. The SHI/STY genes showed expression patterns with variations on a common theme of activity in incipient and developing cotyledon and Leaf primordia, narrowing to apices and hydathode regions. Mutant analysis of single to quintuple mutant combinations revealed dose-dependent defects in Vein patterning affecting multiple Vein traits, most notably in cotyledons. Here we demonstrate that local regulation of auxin biosynthesis is an important aspect of Leaf Vein development. Our findings also support a model in which auxin synthesized at the periphery of primordia affects Vein development.

Enrico Scarpella - One of the best experts on this subject based on the ideXlab platform.

  • coordination of cell polarity and the patterning of Leaf Vein networks
    Current Opinion in Plant Biology, 2018
    Co-Authors: Nguyen Manh Linh, Carla Verna, Enrico Scarpella
    Abstract:

    During development, the behavior of cells in tissues is coordinated along specific orientations or directions by coordinating the polar localization of components in those cells. The coordination of such cell polarity is perhaps nowhere more spectacular than in developing leaves, where the polarity of hundreds of cells is coordinated in the Leaf epidermis and inner tissue to pattern Vein networks. Available evidence suggests that the spectacular coordination of cell polarity that patterns Vein networks is controlled by auxin transport and levels, and by genes that have been implicated in the polar localization of auxin transporters.

  • patterning of Leaf Vein networks by convergent auxin transport pathways
    PLOS Genetics, 2013
    Co-Authors: Megan G. Sawchuk, Alexander Edgar, Enrico Scarpella
    Abstract:

    The formation of Leaf Vein patterns has fascinated biologists for centuries. Transport of the plant signal auxin has long been implicated in Vein patterning, but molecular details have remained unclear. Varied evidence suggests a central role for the plasma-membrane (PM)-localized PIN-FORMED1 (PIN1) intercellular auxin transporter of Arabidopsis thaliana in auxin-transport-dependent Vein patterning. However, in contrast to the severe Vein-pattern defects induced by auxin transport inhibitors, pin1 mutant leaves have only mild Vein-pattern defects. These defects have been interpreted as evidence of redundancy between PIN1 and the other four PM-localized PIN proteins in Vein patterning, redundancy that underlies many developmental processes. By contrast, we show here that Vein patterning in the Arabidopsis Leaf is controlled by two distinct and convergent auxin-transport pathways: intercellular auxin transport mediated by PM-localized PIN1 and intracellular auxin transport mediated by the evolutionarily older, endoplasmic-reticulum-localized PIN6, PIN8, and PIN5. PIN6 and PIN8 are expressed, as PIN1 and PIN5, at sites of Vein formation. pin6 synthetically enhances pin1 Vein-pattern defects, and pin8 quantitatively enhances pin1pin6 Vein-pattern defects. Function of PIN6 is necessary, redundantly with that of PIN8, and sufficient to control auxin response levels, PIN1 expression, and Vein network formation; and the Vein pattern defects induced by ectopic PIN6 expression are mimicked by ectopic PIN8 expression. Finally, Vein patterning functions of PIN6 and PIN8 are antagonized by PIN5 function. Our data define a new level of control of Vein patterning, one with repercussions on other patterning processes in the plant, and suggest a mechanism to select cell files specialized for vascular function that predates evolution of PM-localized PIN proteins.

Shuoxin Zhang - One of the best experts on this subject based on the ideXlab platform.

  • plant phylogeny and growth form as drivers of the altitudinal variation in woody Leaf Vein traits
    Frontiers in Plant Science, 2020
    Co-Authors: Ruili Wang, Haoxuan Chen, Xinrui Liu, Zhibo Wang, Jingwen Wen, Shuoxin Zhang
    Abstract:

    Variation in Leaf Veins along environmental gradients reflects an important adaptive strategy of plants to the external habitats, because of their crucial roles in maintaining Leaf water status and photosynthetic capacity. However, most studies concentrate on a few species and their Vein variation across horizontal spatial scale, we know little about how Vein traits shift along the vertical scale, e.g., elevational gradient along a mountain, and how such patterns are shaped by plant types and environmental factors. Here, we aimed to investigate the variation in Leaf Vein traits (i.e., Vein density, VD; Vein thickness, VT; and Vein volume per unit Leaf area, VV) of 93 woody species distributed along an elevational gradient (1,374-3,375 m) in a temperate mountain in China. Our results showed that altitude-related trends differed between growth forms. Tree plants from higher altitudes had lower VD but higher VT and VV than those from lower altitude; however, the opposite tend was observed in VD of shrubs, and no significant altitudinal changes in their VT or VV. Plant phylogenetic information at the clade level rather than climate explained most of variation in three Leaf Vein traits (17.1-86.6% vs. <0.011-6.3% explained variance), supporting the phylogenetic conservatism hypothesis for Leaf Vein traits. Moreover, the phylogenetic effects on Vein traits differed between trees and shrubs, with the Vein traits of trees being relatively more conserved. Together, our study provides new picture of Leaf Vein variation along the altitude, and highlights the importance of taking plant phylogeny into consideration when discussing trait variation from an ecological to a biogeographic scale.

  • Plant Phylogeny and Growth Form as Drivers of the Altitudinal Variation in Woody Leaf Vein Traits.
    Frontiers in plant science, 2020
    Co-Authors: Ruili Wang, Haoxuan Chen, Xinrui Liu, Zhibo Wang, Jingwen Wen, Shuoxin Zhang
    Abstract:

    Variation in Leaf Veins along environmental gradients reflects an important adaptive strategy of plants to the external habitats, because of their crucial roles in maintaining Leaf water status and photosynthetic capacity. However, most studies concentrate on a few species and their Vein variation across horizontal spatial scale, we know little about how Vein traits shift along the vertical scale, e.g., elevational gradient along a mountain, and how such patterns are shaped by plant types and environmental factors. Here, we aimed to investigate the variation in Leaf Vein traits (i.e., Vein density, VD; Vein thickness, VT; and Vein volume per unit Leaf area, VV) of 93 woody species distributed along an elevational gradient (1,374-3,375 m) in a temperate mountain in China. Our results showed that altitude-related trends differed between growth forms. Tree plants from higher altitudes had lower VD but higher VT and VV than those from lower altitude; however, the opposite tend was observed in VD of shrubs, and no significant altitudinal changes in their VT or VV. Plant phylogenetic information at the clade level rather than climate explained most of variation in three Leaf Vein traits (17.1-86.6% vs.

Wangyu Liu - One of the best experts on this subject based on the ideXlab platform.

  • Multiscale Simulation of a Novel Leaf-Vein-inspired Gradient Porous Wick Structure
    Journal of Bionic Engineering, 2019
    Co-Authors: Yuanqiang Luo, Wangyu Liu, Jingren Gou
    Abstract:

    With the rapid development of photoelectric products, their miniaturization and high integration have intensified the problem of heat dissipation. Vapor chamber is a special type of heat pipe that is a particularly effective heat spreader for electronics. In this paper, a novel Leaf-Vein-inspired Gradient Porous (LGP) wick structure is designed macroscopically and the LGP design is verified using a general model. After that, the gradient porous design Model 1G is selected for the subsequent mesoscopic modeling. Then a connected 2D random LGP wick model presenting porosity gradient is generated by the expanded quartet structure generation set method. Using the mesoscopic Lattice Boltzmann Method (LBM), the flow and heat transfer in the LGP wick model is analyzed. For verification, FLUENT based on the macroscopic finite volume method is used as a benchmark. Finally, the microscopic flow behaviors in the 2D random LGP wick model are analyzed using the LBM developed. Observing the entire flowing process from the inlet to outlet, it is possible to explain the mesoscopic and macroscopic phenomena well based on the microscopic flow behaviors.

  • Water transport in Leaf Vein systems and the flow velocity measurement with a new method
    Journal of plant physiology, 2016
    Co-Authors: Wangyu Liu, Li Wang, Yuanqiang Luo, Tao Luo, Yi Peng
    Abstract:

    Abstract As an exploration to the nature, research about plants⿿ physiological properties have never been suspended. Water transport in Leaf Vein systems is an essential part of plant growth and development. In this paper, a simple but efficient method combined the fluorescence labeling technology frequently used in bioresearch and the image-processing technology in the computer realm was developed to measure the flow velocity, which was used as a quantitative description to reveal the regulation of water transport in Leaf Vein systems. Three ordinary species of plants were selected for the experiments and the influence of the experimental conditions, such as the concentration of fluorescein and illumination intensity of LEDs, was investigated. Differences among the flow velocities of different Leaf Veins of the same Leaf as well as the flow velocities of different species were shown in bar charts. The mean measured flow velocities of the midrib and secondary Vein of Ficus virens Ait. var. sublanceolata (Miq.) Corner were 4.549 m/h and 3.174 m/h. As for Plumeria rubra L. cv. Acutifolia and Hamelia patens , that were 0.339 m/h and 0.463 m/h, 2.609 m/h and 2.586 m/h, respectively. With the algorithm developed in this paper, the variation of the flow velocity in Leaf Veins was investigated by setting a constant time interval. Then a verification of the flow velocity measured by the algorithm was performed. Finally, according to the natural conditions of a plant Leaf, a simulation about the water transport in Leaf Vein systems was carried out, which is especially different from the previous research.

  • Heat and mass transfer characteristics of Leaf-Vein-inspired microchannels with wall thickening patterns
    International Journal of Heat and Mass Transfer, 2016
    Co-Authors: Yuanqiang Luo, Wangyu Liu, Li Wang, Weigui Xie
    Abstract:

    Abstract Leaf Veins are the channels for water and nutrient transportation within plant leaves. In recent years, the excellent heat and mass transfer characteristics of natural reticulate Leaf Veins structure has inspired many researchers in the structural design of various microchannels. In this paper, three different models of Leaf-Vein-inspired microchannels with wall thickening patterns are established base on the real microstructures of the xylem vascular bundles in the midribs of the leaves of three ordinary species of plants with heat-resistance. Their heat and mass transfer characteristics are investigated through numerical simulation and compared by using three assessment criteria, the Poiseuille number, the average Nusselt number and the thermal performance index. Numerical analyses about the influences of the dimensions of the reticulate/pitted wall thickening patterns are also performed. Additionally, an application of the Leaf-Vein-inspired microchannels on microchannel heat sink is demonstrated and the heat and mass transfer characteristics among six different models are compared. The results indicate that the natural selected structure of the xylem vascular bundles in the Leaf Veins can provide excellent heat transfer characteristic with a smaller volume while sacrificing a little bit ability in mass transfer, which might be used as a promising design method for some heat dissipation devices.

  • The performance of the novel vapor chamber based on the Leaf Vein system
    International Journal of Heat and Mass Transfer, 2015
    Co-Authors: Yi Peng, Wangyu Liu, Liu Bin, Jieqiong Liu, Kaidong Huang, Li Wang, Chen Wei
    Abstract:

    Abstract With the upgrade of the miniaturization of the electronic equipment, heat in per area increases dramatically, which leads to the strong need for a high efficient device of heat dissipation. As the result of the nature evolution, Leaf Vein system is an excellent structure for heat and mass transfer but has not been widely studied. Based on the Leaf Vein system, a conceptual structure is designed to form the wick of a vapor chamber, in which the Leaf-Vein-like fractal network and the micro fin-pins are used to simulate the Leaf Vein network and mesophyll tissue respectively. In the experiment, the Leaf-Vein-like structure is manufactured by chemical etching, and two different vapor chambers (diameter is 90 mm, the evaporator and condenser have the same wick structures) with and without strength boiling are compared concerning their cooling performances. The experiment result shows that when the diameter of the heating rod is 35 mm, the vapor chamber can perform good temperature uniformity and small thermal resistance with the input power Q  ⩽ 90 W. When the deionized water is used as the working fluid, the thermal resistance of the vapor chamber is smaller than 0.3 °C/W.

  • A novel wick structure of vapor chamber based on the fractal architecture of Leaf Vein
    International Journal of Heat and Mass Transfer, 2013
    Co-Authors: Yi Peng, Wangyu Liu, Ningling Wang, Tian Yufu, Xuelin Chen
    Abstract:

    Abstract A new pattern of wick in vapor chamber is designed and analyzed in this study. The wick is a kind of Leaf-Vein-like fractal architecture with polygon loops which are composed of many Y-shaped bifurcations, for this reason that the condensable area is enlarged efficiently. The polygonal loops play a unique role in avoiding blocking. And the sucking capacity is introduced to evaluate the wick performance. The permeability in both the length and height direction as well as the resistance in length direction are calculated, and compared with the parallel structure. It shows the permeability in both directions is far greater than that of the parallel structure under the same power source condition. Not only that, the resistance is far less than that of the parallel structure as the reasonable width ratio was chose. The analytical results indicate that the Leaf-Vein-like fractal architecture has better performance than the parallel structure.