Acta Botanica Croatica, Vol. 62 No. 1, 2003.
Original scientific paper
Chloroplast structure and function in wild-type and aurea-type leaves of the Japanese spindle-tree over their life span
N. Ljubešić
M. Wrischer
T. Prebeg
Z. Devidé
Abstract
The evergreen leaves of the Japanese spindle-tree (Euonymus japonicus Thunb. 'Aureomarginatus') are adapted to endure repeated freezing and thawing during the winter. We investigated the physiological and morphological characteristics of the chloroplasts in
young, overwintering, and overwintered wild-type and aurea-type leaves. When developing in the shade, both leaf types during their life span maintained a well-developed thylakoid system in their chloroplasts. The photosynthesis rates were also similar. When
growing in intense sunlight, the aurea variety contained chloroplasts with a reduced thylakoid system, but photosynthesis was less reduced. In spring, overwintered leaves of both varieties clearly showed ultrastructural and physiological characteristics of senescence. The senescence in aurea leaves exposed to full sunlight was more pronounced.
Keywords
Euonymus japonicus; wild-type plant; aurea-variety; overwintered leaves; chloroplast; ultrastructure; photosynthesis
Hrčak ID:
3539
URI
Publication date:
5.6.2003.
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