74: 43-57
Wojciech Kraj
Chlorophyll degradation and the activity of chlorophyllase and Mg-dechelatase during leaf senescence in Fagus sylvatica
Dendrobiology 2015, vol. 74: 43-57
http://dx.doi.org/10.12657/denbio.074.005
Abstract:
The induction and course of autumn leaf senescence in early, intermediate and late phenological forms of beech (Fagus sylvatica L.) was studied by analysing the contents of chlorophyll a and b, chlorophyll degradation products and the activities of chlorophyllase and Mg-dechelatase. Studies were conducted in two beech stands differing in the date of senescence onset. Leaf samples were collected from July to October in 2007 and 2009. The main trigger of leaf senescence in beech was a temperature drop occurring in parallel with the appropriate photoperiod. The early phenological form was the most sensitive to temperature. Chlorophyll degradation in senescing leaves of this form occurred in three stages, which strongly coincided with the dates of sudden temperature drops. These stages were less visible in the intermediate form, whereas chlorophyll degradation in the late form was the most stable and occurred in two stages. The fraction of chlorophyllides and phaeophytin in relation to chlorophylls in the early phenological form was significantly higher than that in the late form. Biochemical analyses indicate that pigment dephytylation associated with an increase in chlorophyllase activity is an early reaction of chlorophyll degradation, whereas the Mg-dechelating reaction was much less important. The correlation coefficients between the proportion of chlorophyllides and chlorophyll content for the early, intermediate and late phenological forms were –0.90, –0.87 and –0.72, respectively, providing evidence of chlorophyllase activity in vivo. The activity of chlorophyllase depended significantly on the phenological form. All chlorophyll degradation parameters were highly correlated with temperature changes during senescence. The early phenological form was characterised by the highest correlation coefficients.
Additional key words: beech, autumn senescence, phenological forms, chlorophyll-degrading enzymes
 |
 |
Zmień kontrast
Dostosuj czcionkę
W ramach dotacji Powiatu Poznańskiego na prace konserwatorskie, restauratorskie lub roboty budowlane przy zabytku, nasze Arboretum otrzymało środki na realizację projektu pt. Wyeksponowanie oryginalnych elementów zabytkowego ogrodu poprzez przebudowę odcinka alejek parkowych w Arboretum w Kórniku.
Przedsięwzięcie pn.: "Doposażenie sal edukacyjnych Instytutu Dendrologii Polskiej Akademii Nauk w Kórniku w sprzęt i pomoce naukowe potrzebne do prowadzenia edukacji przyrodniczej i ekologicznej" dofinansowano ze środków Wojewódzkiego Funduszu Ochrony Środowiska i Gospodarki Wodnej w Poznaniu.
Zakup sprzętu i oprogramowania, materiałów i pomocy dydaktycznych wykorzystywanych w działalności edukacyjnej Instytutu Dendrologii PAN oraz opracowanie i wydruk przewodników przyrodniczych dla dzieci.
