Portal de Periódicos da CAPES

Changes in glucose and fructose level inNicotiana alata styles and ovaries accompanying compatible and incompatible pollen tube growth

1961; Institute of Experimental Botany of the Czech Academy of Sciences; Volume: 3; Issue: 1 Linguagem: Inglês

10.1007/bf02933498

1573-8264

J. Tupý,

Plant nutrient uptake and metabolism

If the flowers for experiment were separated from the plants one day before pollination and incubated in water at a temperature of 25° C, pollen tube growth in the pistils made itself apparent during the following three days in the glucose and fructose level. On the first day after pollination the amount of these sugars in the apical style parts was higher in non-pollinated flowers, while on the other hand, in most cases it was lower in the basal sections and ovaries than in the corresponding parts of pollinated flowers. During the next two days there was a greater loss of both carbohydrates where pollination, particularly allogamy, occurred, so that after the third day the glucose and fructose level was highest in the non-pollinated pistils and lowest after compatible pollination. This decrease was most pronounced in the ovaries even though the compatible tubes had not yet penetrated into them. In experiments in which the flowers were left on plants cultivated under field conditions, a decrease in the glucose and fructose content of their pistils had not occurred even 80 hours after compatible pollination. From these facts the following conclusions can be drawn: The growth of the tubes through the styles causes an increased inflow of carbohydrates into the whole pistils. Both compatible and incompatible tubes use sugars from the style tissue. Both these phenomena are more intense after allogamy than in the case of incompatible autogamy. In view of the fact that compatible tubes grew normally through the styles even with a lowered glucose and fructose level, an absolute rise in the content of these sugars in the pistils is not necessary for tube growth. The proportion of glucose/fructose in pollinated styles changes in favour of glucose. The value of this quotient rises both in the apical and basal style parts mainly, however, after compatible pollination. This phenomena is in agreement with the previous hypothesis (TUPý 1959, 1960), according to which, in the respiratory process, pollen tubes consume mainly sucrose and from this, primarily its fructofuranose component.