Detalhes do Documento

This work had three main goals: (1) to study the process of the phellogen and first periderm formation in young plants of cork-oak (Quercus suber); (2) to study the process of cork-tissue formation in adult cork-oak trees under cork exploitation, including the suberification process of cork cell walls and, (3) to study the structure of suberized cell walls in the periderm of potatoes, including a wild-type and three mutatans, where genes involved in suberin synthesis were supressed. To this end were used optical microscopy techniques, including bright field, epi-fluorescence and polarized light, together with scanning electron microscopy (SEM). The main results were: · the phellogen is formed in cork-oak before a month’s life of the young plants; · in the cork forming tissue three zones can be seen – the outer one, where cells are still dividing; – a middle one, were cork cell walls are thickening, and the inner one, contiguous to the mature cells, were cells still kept abundant cytoplasm material, although their cell walls already show their definitive thickness and, · the silencing of the genes involved in the ester-linking between the aliphatic and aromatic domains of suberin have the higher effect in the disrupting of suberized cell walls in potato periderm.