The effect of temperature and ageing on root apical meristems during seedling growth of Triticum aestivum L.: a specific effect on nucleoli |
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| Authors: | E G JORDAN P J COOPER G MARTINI M D BENNETT† R B FLAVELL† |
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| Institution: | Biology Department, Queen Elizabeth College, University of London, London W8 7AH, United Kingdom;Instituto di Mutagenesi e Defferenziamento del CNR, Via Svezia 10, 56100 Pisa, Italy;Plant Breeding Institute, Trumpington, Cambridge CB2 2LQ, United Kingdom |
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| Abstract: | Abstract. Growth and cytology of root apical meristems of Chinese Spring wheat were studied in relation to temperature. The maximum rate of growth increased with temperature, a marked rise occurring between 10°C and 12°C. At all temperatures studied nucleolar volume increased to a maximum and then declined. The maximum nucleolar size achieved showed particular temperature sensitivity, higher volumes being attained at lower temperatures. The peak at 5°C was 70% higher than at 20°C. However, in comparison, cell and nuclear volumes were only 38% and 47% larger, respectively. Ultrastructural analysis of the nucleoli revealed a temperature-dependent relationship between the proportion of granular component and dense fibrillar component. The results are discussed in relation to the regulation of ribosome synthesis and function during growth and development at different temperatures. |
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| Keywords: | Triticum aestivum L ev Chinese Spring Gramineae wheat cytology electron microscopy nucleolus development temperature |
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