High-speed pollen release in the white mulberry tree, Morus alba L

Taylor, Philip; Card, Gwyneth M; House, James; Dickinson, Michael H.; Flagan, Richard C.

doi:10.1007/s00497-005-0018-9

Cited by 57 publications

(58 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…1). Another mechanism observed in allergenic plants involved the rapid straightening of the stamen and propulsion of pollen grains into the air at speeds in excess of Mach 0.7 [11]. This was observed in mulberry, and the mechanism is common to wall pellitory ( Parietaria species) and related taxa.…”

Section: Pollen Presentation and Fragmentationmentioning

confidence: 99%

Links between Pollen, Atopy and the Asthma Epidemic

Taylor

Jacobson²,

House

et al. 2007

Int Arch Allergy Immunol

Self Cite

102

View full text Add to dashboard Cite

Pollen allergy has been found in 80–90% of childhood asthmatics and 40–50% of adult-onset asthmatics. Despite the high prevalence of atopy in asthmatics, a causal relationship between the allergic response and asthma has not been clearly established. Pollen grains are too large to penetrate the small airways where asthma occurs. Yet pollen cytoplasmic fragments are respirable and are likely correlated with the asthmatic response in allergic asthmatics. In this review, we outline the mechanism of pollen fragmentation and possible pathophysiology of pollen fragment-induced asthma. Pollen grains rupture within the male flowers and emit cytoplasmic debris when winds or other disturbances disperse the pollen. Peak levels of grass and birch pollen allergens in the atmosphere correlated with the occurrence of moist weather conditions during the flowering period. Thunderstorm asthma epidemics may be triggered by grass pollen rupture in the atmosphere and the entrainment of respirable-sized particles in the outflows of air masses at ground level. Pollen contains nicotinamide adenine dinucleotide phosphate (reduced) oxidases and bioactive lipid mediators which likely contribute to the inflammatory response. Several studies have examined synergistic effects and enhanced immune response from interaction in the atmosphere, or from co-deposition in the airways, of pollen allergens, endogenous pro-inflammatory agents, and the particulate and gaseous fraction of combustion products. Pollen and fungal fragments also contain compounds that can suppress reactive oxidants and quench free radicals. It is important to know more about how these substances interact to potentially enhance, or even ameliorate, allergic asthma.

show abstract

Section: Pollen Presentation and Fragmentationmentioning

confidence: 99%

Links between Pollen, Atopy and the Asthma Epidemic

Taylor

Jacobson²,

House

et al. 2007

Int Arch Allergy Immunol

Self Cite

102

View full text Add to dashboard Cite

show abstract

“…shedding problem is the generation of internal forces causing pollen grains to catapult or explode from the anther into the air column [10][11][12]; but these mechanisms appear to be quite restricted taxonomically and do not likely represent the general case for wind-pollinated angiosperms. Alternatively, pollen may be removed passively from the anther by aerodynamic forces (e.g.…”

Section: Introductionmentioning

confidence: 99%

Turbulence-induced resonance vibrations cause pollen release in wind-pollinated Plantago lanceolata L. (Plantaginaceae)

Timerman

Greene

Urzay

et al. 2014

J. R. Soc. Interface.

View full text Add to dashboard Cite

In wind pollination, the release of pollen from anthers into airflows determines the quantity and timing of pollen available for pollination. Despite the ecological and evolutionary importance of pollen release, wind-stamen interactions are poorly understood, as are the specific forces that deliver pollen grains into airflows. We present empirical evidence that atmospheric turbulence acts directly on stamens in the cosmopolitan, wind-pollinated weed, Plantago lanceolata, causing resonant vibrations that release episodic bursts of pollen grains. In laboratory experiments, we show that stamens have mechanical properties corresponding to theoretically predicted ranges for turbulence-driven resonant vibrations. The mechanical excitation of stamens at their characteristic resonance frequency caused them to resonate, shedding pollen vigorously. The characteristic natural frequency of the stamens increased over time with each shedding episode due to the reduction in anther mass, which increased the mechanical energy required to trigger subsequent episodes. Field observations of a natural population under turbulent wind conditions were consistent with these laboratory results and demonstrated that pollen is released from resonating stamens excited by small eddies whose turnover periods are similar to the characteristic resonance frequency measured in the laboratory. Turbulencedriven vibration of stamens at resonance may be a primary mechanism for pollen shedding in wind-pollinated angiosperms. The capacity to release pollen in wind can be viewed as a primary factor distinguishing animal-from wind-pollinated plants, and selection on traits such as the damping ratio and flexural rigidity may be of consequence in evolutionary transitions between pollination systems.

show abstract

“…In contrast to these active mechanisms, the N. gracilis lid movement requires neither mechanical preloading nor physiological activation. The fastest reported plant movements-up to 170 ms −1 in extreme cases-are catapult-based mechanisms for seed dispersal (5,39,40), spore release (6), and pollen transfer (7,41). These superfast motions invariably rely on irreversible, singleshot mechanisms.…”

Section: Discussionmentioning

confidence: 99%

Mechanism for rapid passive-dynamic prey capture in a pitcher plant

Bauer

Paulin

Robert

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Plants use rapid movements to disperse seed, spores, or pollen and catch animal prey. Most rapid-release mechanisms only work once and, if repeatable, regaining the prerelease state is a slow and costly process. We present an encompassing mechanism for a rapid, repeatable, passive-dynamic motion used by a carnivorous pitcher plant to catch prey. Nepenthes gracilis uses the impact of rain drops to catapult insects from the underside of the canopy-like pitcher lid into the fluid-filled trap below. High-speed video and laser vibrometry revealed that the lid acts as a torsional spring system, driven by rain drops. During the initial downstroke, the tip of the lid reached peak velocities similar to fast animal motions and an order of magnitude faster than the snap traps of Venus flytraps and catapulting tentacles of the sundew Drosera glanduligera. In contrast to these active movements, the N. gracilis lid oscillation requires neither mechanical preloading nor metabolic energy, and its repeatability is only limited by the intensity and duration of rainfall. The underside of the lid is coated with friction-reducing wax crystals, making insects more vulnerable to perturbations. We show that the trapping success of N. gracilis relies on the combination of material stiffness adapted for momentum transfer and the antiadhesive properties of the wax crystal surface. The impact-driven oscillation of the N. gracilis lid represents a new kind of rapid plant movement with adaptive function. Our findings establish the existence of a continuum between active and passive trapping mechanisms in carnivorous plants.

show abstract

High-speed pollen release in the white mulberry tree, Morus alba L

Cited by 57 publications

References 11 publications

Links between Pollen, Atopy and the Asthma Epidemic

Links between Pollen, Atopy and the Asthma Epidemic

Turbulence-induced resonance vibrations cause pollen release in wind-pollinated Plantago lanceolata L. (Plantaginaceae)

Mechanism for rapid passive-dynamic prey capture in a pitcher plant

Contact Info

Product

Resources

About