The Role of Wheat Awns in the Seed Dispersal Unit

@article{Elbaum2007TheRO,
  title={The Role of Wheat Awns in the Seed Dispersal Unit},
  author={Rivka Elbaum and Liron Zaltzman and Ingo Burgert and Peter Fratzl},
  journal={Science},
  year={2007},
  volume={316},
  pages={884 - 886}
}
The dispersal unit of wild wheat bears two pronounced awns that balance the unit as it falls. We discovered that the awns are also able to propel the seeds on and into the ground. The arrangement of cellulose fibrils causes bending of the awns with changes in humidity. Silicified hairs that cover the awns allow propulsion of the unit only in the direction of the seeds. This suggests that the dead tissue is analogous to a motor. Fueled by the daily humidity cycle, the awns induce the motility… 

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References

SHOWING 1-10 OF 15 REFERENCES

The effects of morphology, orientation and position of grass diaspores on seedling survival.

Following a forest fire, a three-fold increase in the density of grass seedlings was recorded and the relative abundance of seedlings from unappendaged diaspores rose dramatically, and it is suggested that fire may release many of these seeds from dormancy.

THE MECHANICS OF SEED EXPULSION IN ACANTHACEAE

Abstract The bilocular seed capsules of species on the Acanthaceae subfamily Acanthoideae are either hygrochastic or xerochastic, but in both cases the mechanism for seed expulsion is similar; only

A Day in the Life of a Seed: Movements and Fates of Seeds and Their Implications for Natural and Managed Systems

A model that outlines the movements and fates of seeds after they leave the parent plant is developed, and the relative influences of abiotic and biotic factors are examined.

How pine cones open

The scales of seed-bearing pine cones move in response to changes in relative humidity. The scales gape open when it is dry, releasing the cone's seeds. When it is damp, the scales close up. The

SEED ENTRAPMENT IN ALPINE ECOSYSTEMS: EFFECTS OF SOIL PARTICLE SIZE AND DIASPORE MORPHOLOGY'

It is indicated that on exposed soils in windy environments diaspore morphology and soil particle size greatly affect the spatial distribution of diaspores in seed banks and the optimal soil type traps a high number of diasores but precludes significant downward movement.

THE INFLUENCE OF DIASPORE MORPHOLOGY AND SOIL-SURFACE PROPERTIES ON THE DISTRIBUTION OF GRASSES

It is suggested that actively-awned species predominate since their diaspores are at a competitive advantage in locating microsites and the preponderance of unawnedspecies over passively-awning species results from the effects of fire.

Structure and morphology of cellulose in wheat straw

The structure and morphology of cellulose extracted from wheat were studied. It was found that the extraction process is effective and hemicelluloses and lignin can be extracted completely. Cellulose

A Study of the Physical and Mechanical Properties of Wheat Straw

Abstract A series of experiments was conducted to measure the physical properties, tensile and shear strengths and elastic moduli of stem between nodes of wheat straw (var Mercia). These stems are

Cell-wall recovery after irreversible deformation of wood

It is suggested that the molecular recovery mechanism in the cell matrix is a universal phenomenon dominating the tensile deformation of different wood tissue types.

The longitudinal Young's modulus of Pinus radiata

  • I. D. Cave
  • Materials Science
    Wood Science and Technology
  • 2004
SummaryThe variation of the longitudinal Young's modulus with mean cellulose microfibril angle of the wood substance of the earlywood of a softwood has been determined from small clear samples.The