bioRxiv ScienceSearch

Biology subjects

Sobral, R. S.

Publications and source records attributed to Sobral, R. S..

2 recordsLinked to original sources

Genome-Wide Identification of Epigenetic Regulators in Quercus suber

Modifications of DNA and histones, including methylation and acetylation, are critical for the epigenetic regulation of gene expression during plant development, particularly during environmental adaptation processes. However, information on the enzymes catalyzing all these modifications in perennial trees, such as Quercus suber, is still not available. In this study, several epigenetic modifier proteins, including eight DNA methyltransferases (DNA Mtases), three DNA demethylases (DDMEs) and ninety-one histone modifiers including thirty-five histone methyltransferases (HMTs), twenty-six histone demethylases (HDMTs), eight histone acetyltransferases (HATs) and twenty-two histone acetylases (HDACs) were identified in Q. suber. Phylogenetic analyses of the DNA and histone modifier proteins were performed using several plant species homologs, enabling the classification of the Q. suber proteins. Additional in silico analysis showed that some Q. suber DNA Mtases, DMEs and histone modifiers have the typical domains found in the plant model Arabidopsis, which might suggest a conserved functional role. A link between the expression levels of each gene in different Q. suber tissues (buds, flowers, acorns, embryos, cork and roots) with the functions already known for their closest homologs in other species was also established. Therefore, the data generated here are important for future studies exploring the role of epigenetic regulators in this economically important species.

genomics

Unisexual flower initiation in the monoecious Quercus suber L., a molecular approach

Several plant species display a temporal separation of the male and female flower organ development to enhance outbreeding, however, little is known regarding the genetic mechanisms controlling this temporal separation. Quercus suber is a monoecious oak tree with accentuated protandry: in late winter, unisexual male flowers emerge adjacent to the swollen buds, whereas unisexual female flowers emerge in the axils of newly formed leaves formed during spring (4 to 8 weeks after male flowering). Here, phylogenetic profiling lead to the identification of cork oak homologs of key floral regulatory genes. The role of these cork oak homologs during flower development was identified with functional studies in Arabidopsis thaliana. The expression profile of flower regulators (inducers and repressors) throughout the year, in leaves and buds, suggests that the development of male and female flowers may be preceded by separated induction events. Female flowers are most likely induced during the vegetative flush occurring in spring, whereas male flowers may be induced in early summer, staying enclosed within the pre-dormant buds, but complete their development before the vegetative flush of the following year, displaying a long period of anthesis that spans the dormant period. Results portray a genetic mechanism that may explain similar reproductive habits in other tree species.

plant biology