Accumulation of carbon compounds in the epidermis of five species with either different photosynthetic systems or stomatal structure

Autor: Nicolette Thorpe
Rok vydání: 1980
Předmět:
Zdroj: Plant, Cell and Environment. 3:451-460
ISSN: 1365-3040
0140-7791
DOI: 10.1111/1365-3040.ep11587001
Popis: Measurements were made of the rate and pattern of 14CO2 fixation by the attached and detached epidermis and accompanying leaf tissue of Commelina cyanea (C3), Zea mays (C4), Kalanchoe daigremontiana (CAM), Allium cepa (C3) and Paphiopedilum venustum (C3). Guard cell plastids of the last two species contain no starch and chlorophyll, respectively. The fine structure of guard cells of these species was also examined. The epidermis of all species when detached from the leaf fixed CO2 by PEP carboxylation but at rates related to those of the underlying mesophyll. When attached to the leaf during 14CO2 feeding a much higher rate of accumulation of radioactivity in substances other than malate and aspartate was found. The results indicated that although concentrations of various metabolites in the two tissues varied greatly, there was fairly ready transport from mesophyll to epidermis. Of recently formed compounds, amino acids appeared to be most readily transported in Commelina and sugars in Zea and Kalanchoe. Epidermal cells appeared to be highly permeable, there being rapid and extensive loss of most labelled products from epidermis placed on CaSO4 solution.
Databáze: OpenAIRE
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