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Descripción
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| Germination begins with the uptake of water by the quiescent seed and is completed when the embryo breaks the seed coat and surrounding tissues thus allowing radicle protrusion. Seedling growth, until photosynthesis is fully established, is considered a post-germination process. In both phases, germination sensu stricto and postgermination, the expression of different types of hydrolases takes place in a controlled way and this control takes place mainly at the level of transcription. During the germination sensu stricto of Brassicaceae seeds, the endosperm cell walls (CWs) undergo a remodelling process where endo-ß-mannanases (MAN genes) that catalyze the hydrolysis of ß1?4 bonds in the mannan polymers, have an important role. In post-germination, the mobilization of storage compounds takes place to provide C and N skeletons and energy for the development of the growing seedling; particularly, proteins are hydrolysed by the action of proteases, mainly of the CathepsinB-like type (CathB genes). Here we describe the main TFs regulating MAN7 and CathB3 genes in germinating Arabidopsis Thaliana seeds. The transcriptional control depends on interactions between cis-elements in gene promoters and transcription factor proteins (TFs). To identify functional relevant cis-elements an in silico phylogenetic shadowing approach has been used coupled with screenings of an arrayed library of circa 1,200 Arabidopsis Thaliana TFs in yeast. The TFs thus identified, have been validated through molecular techniques and their physiological relevance established by reverse genetic approaches. Comparison with TFs regulating similar seed transcriptional networks in barley crops, as well as, similarities and differences between the monocot- and dicotyledoneous seed germination are discussed. | |
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Internacional
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Si |
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ISSN o ISBN
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000-000 |
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Entidad relacionada
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Sociedade Portuguesa de Fisiologia Vegetal y Sociedad Española de Fisiología Vegetal |
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Nacionalidad Entidad
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PORTUGAL |
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Lugar del congreso
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Lisboa (Portugal) 24 al 28 Julio de 2013. |