Naslov
Collapsing pollen grains

Autori
Božič, Anže ; Šiber, Antonio

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Xmas Biophysics Workshop Gradisca d'Isonzo Book of Abstracts / - , 2019, 21-21

Skup
Xmas Biophysics Workshop

Mjesto i datum
Gradisca d'Isonzo, Italija, 09.12.2019. - 10.12.2019

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
pollen, mechanics, desiccation, hydration, buckling, collapse, shell, elasticity

Sažetak
Pollen grains come in all sorts of shapes - they can be spherical, ellipsoidal, lobate, prismatic, polyhedral, and then, there are some which escape easy qualification in terms of geometry. The sizes also differ very much, from less than 10 micrometers (e.g. in Myosotis scorpioides or nontiscordardimè delle paludi, Vergissmeinnicht, močvirska spominčica, and močvarni nezaboravak, as we say in Italian, German, Slovenian and Croatian, respectively) to more than 100 micrometers (e.g. in Cucurbita pepo or zucchino, Gartenkürbis, buča, and tikva). Shapes and sizes of grains depend on the specie in question and they are often used to identify the plant, especially in the fossil records. Knowing that all life is related, it is tempting to search for evolutionary reasons for different shapes and sizes of pollen grains. It is also tempting to identify the elements of the "design" and relate them to the function which the pollen grain needs to fulfil. Pollen grains are reasonably elastic shells which contain and protect a sensitive interior - vegetative and generative cells, whose preservation is essential for fertilization. They need to function on a border of stability, i.e. need to be sufficiently strong to protect the interior, yet sufficiently labile to activate and release the interior once they reach a suitable environment. This happens once they land on a stigma of a flowering plant. In order to function properly, these shells need to conform to specific mechanical requirements. These include the resistance of shells to the effective pressure from the outside - the pollen grains crumple and deform upon desiccation. Yet, the crumpling (or buckling) is often not irregular and catastrophic, which is what the word usually suggests in the mechanical context. The inward buckling of the pollen grains proceeds often orderly and reversibly due to specific mechanical features of the grain design. A classical theory of shell elasticity can be profitably applied to learn more about such systems, as will be shown.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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