Determinació de l’expressió diferencial de gens al llarg del creixement estaciónal del suro

Abstract

The presented thesis is related to the cork formation. The objective is to determine by quantitative PCR (qPCR) the expression level of a group of candidate genes for a better understanding about the possible role of these genes and the molecular basis for the cork formation. For these genes has been analyzed its specificity phellem through the comparison between secondary tissue producer suberin (phellem/cork) and non-secondary tissue producer suberin (xylem/wood) in samples of cork oak obtained on the period of maximum growth of cork; the differential expression between phellem of cork oak (Quercus suber) and holm oak (Quercus ilex), to understand the relevance of these selected genes in the formation process since the cork oak produces many more layers of cells of phellem for growth station than the holm oak; and the expression pattern of these genes during seasonal growth of cork in phellem samples obtained along the period of growth, to understand through the seasonal variation in their expression as they are involved in the formation of cork and comparing the expression pattern of other genes previously studied. For some of the candidate genes selected has been validated an specificity in suberized tissues (phellem); it checked that the candidate genes of phellem together are expressed although more in cork oak, and thus validated the results of the study by massive sequencing of the transcriptome comparison of cork oak and holm oak; and the seasonal pattern has been determined for all the candidate genes. The results of the seasonal pattern allowed us to see that the structural genes related to lipid synthesis and deposition of suberin, are following a seasonal pattern typical of suberin genes and that hormone receptors are more active phase of maximum growth of cork; and about the regulatory genes, RIK possibly is a negative regulator of the process of cork formation, WOX4 could play an important role related to the maintenance of undifferentiated cork cambium in to the start of the growing season during in the april, and AP1 is more active on the maximum formation and development of cork period