Carmen Rodriguez Gacio - Academia.edu (original) (raw)

Papers by Carmen Rodriguez Gacio

The Nitrate Afterripening Crosstalk Is Involved in the Testa Rupture of Sisymbryum Offinales Seed Xiii Congresso Luso Espanhol De Fisiologia Vegetal 24 07 2013 28 07 2013 Lisbon Portugal, 2013

Planta, 2010

Mannans are hemicellulosic polysaccharides in the plant primary cell wall (CW). Mature seeds, spe... more Mannans are hemicellulosic polysaccharides in the plant primary cell wall (CW). Mature seeds, specially their endosperm cells, have CWs rich in mannan-based polymers that confer a strong mechanical resistance for the radicle protrusion upon germination. The rupture of the seed coat and endosperm are two sequential events during the germination of Arabidopsis thaliana. Endo-jS-mannanases (MAN; EC. 3.2.1.78) are hydrolytic enzymes that catalyze cleavage of {i\-> 4 bonds in the mannan-polymer. In the genome of Arabidopsis, the endo-jS-mannanase (MAN) family is represented by eight members. The expression of these eight MAN genes has been systematically explored in different organs of this plant and only four of them (AtMAN7, AtMAN6, AtMAN2 and AtMANS) are expressed in the germinating seeds. Moreover, in situ hybridization analysis shows that their transcript accumulation is restricted to the micropylar endosperm and to the radicle and this expression disappears soon after radicle emergence. T-DNA insertion mutants in these genes (K.O. MAN7, K.O. MAN6, K.O. MAN5), except that corresponding to AtMAN2 (K.O. MAN2), germinate later than the wild type (Wt). K.O. MAN6 is the most affected in the germination time course with a i 50 almost double than that of the Wt. These data suggest that AtMAN7, AtMAN5 and specially AtMAN6 are important for the germination of A. thaliana seeds by facilitating the hydrolysis of the mannan-rich endosperm cell walls.

Plant Signaling & Behavior, 2011

Molecular analysis of endo-β-mannanase genes upon seed imbibition suggest a cross-talk between ra... more Molecular analysis of endo-β-mannanase genes upon seed imbibition suggest a cross-talk between radicle and micropylar endosperm during germination of Arabidopsisthaliana,

Physiologia Plantarum, 2012

Journal of Experimental Botany, 2012

In mammals, cadmium is widely considered as a non-genotoxic carcinogen acting through a methylati... more In mammals, cadmium is widely considered as a non-genotoxic carcinogen acting through a methylation-dependent epigenetic mechanism. Here, the effects of Cd treatment on the DNA methylation patten are examined together with its effect on chromatin reconfiguration in Posidonia oceanica. DNA methylation level and pattern were analysed in actively growing organs, under short-(6 h) and long-(2 d or 4 d) term and low (10 mM) and high (50 mM) doses of Cd, through a Methylation-Sensitive Amplification Polymorphism technique and an immunocytological approach, respectively. The expression of one member of the CHROMOMETHYLASE (CMT) family, a DNA methyltransferase, was also assessed by qRT-PCR. Nuclear chromatin ultrastructure was investigated by transmission electron microscopy. Cd treatment induced a DNA hypermethylation, as well as an up-regulation of CMT, indicating that de novo methylation did indeed occur. Moreover, a high dose of Cd led to a progressive heterochromatinization of interphase nuclei and apoptotic figures were also observed after long-term treatment. The data demonstrate that Cd perturbs the DNA methylation status through the involvement of a specific methyltransferase. Such changes are linked to nuclear chromatin reconfiguration likely to establish a new balance of expressed/repressed chromatin. Overall, the data show an epigenetic basis to the mechanism underlying Cd toxicity in plants.

The Nitrate Afterripening Crosstalk Is Involved in the Testa Rupture of Sisymbryum Offinales Seed Xiii Congresso Luso Espanhol De Fisiologia Vegetal 24 07 2013 28 07 2013 Lisbon Portugal, 2013

Planta, 2010

Mannans are hemicellulosic polysaccharides in the plant primary cell wall (CW). Mature seeds, spe... more Mannans are hemicellulosic polysaccharides in the plant primary cell wall (CW). Mature seeds, specially their endosperm cells, have CWs rich in mannan-based polymers that confer a strong mechanical resistance for the radicle protrusion upon germination. The rupture of the seed coat and endosperm are two sequential events during the germination of Arabidopsis thaliana. Endo-jS-mannanases (MAN; EC. 3.2.1.78) are hydrolytic enzymes that catalyze cleavage of {i\-> 4 bonds in the mannan-polymer. In the genome of Arabidopsis, the endo-jS-mannanase (MAN) family is represented by eight members. The expression of these eight MAN genes has been systematically explored in different organs of this plant and only four of them (AtMAN7, AtMAN6, AtMAN2 and AtMANS) are expressed in the germinating seeds. Moreover, in situ hybridization analysis shows that their transcript accumulation is restricted to the micropylar endosperm and to the radicle and this expression disappears soon after radicle emergence. T-DNA insertion mutants in these genes (K.O. MAN7, K.O. MAN6, K.O. MAN5), except that corresponding to AtMAN2 (K.O. MAN2), germinate later than the wild type (Wt). K.O. MAN6 is the most affected in the germination time course with a i 50 almost double than that of the Wt. These data suggest that AtMAN7, AtMAN5 and specially AtMAN6 are important for the germination of A. thaliana seeds by facilitating the hydrolysis of the mannan-rich endosperm cell walls.

Plant Signaling & Behavior, 2011

Molecular analysis of endo-β-mannanase genes upon seed imbibition suggest a cross-talk between ra... more Molecular analysis of endo-β-mannanase genes upon seed imbibition suggest a cross-talk between radicle and micropylar endosperm during germination of Arabidopsisthaliana,

Physiologia Plantarum, 2012

Journal of Experimental Botany, 2012

In mammals, cadmium is widely considered as a non-genotoxic carcinogen acting through a methylati... more In mammals, cadmium is widely considered as a non-genotoxic carcinogen acting through a methylation-dependent epigenetic mechanism. Here, the effects of Cd treatment on the DNA methylation patten are examined together with its effect on chromatin reconfiguration in Posidonia oceanica. DNA methylation level and pattern were analysed in actively growing organs, under short-(6 h) and long-(2 d or 4 d) term and low (10 mM) and high (50 mM) doses of Cd, through a Methylation-Sensitive Amplification Polymorphism technique and an immunocytological approach, respectively. The expression of one member of the CHROMOMETHYLASE (CMT) family, a DNA methyltransferase, was also assessed by qRT-PCR. Nuclear chromatin ultrastructure was investigated by transmission electron microscopy. Cd treatment induced a DNA hypermethylation, as well as an up-regulation of CMT, indicating that de novo methylation did indeed occur. Moreover, a high dose of Cd led to a progressive heterochromatinization of interphase nuclei and apoptotic figures were also observed after long-term treatment. The data demonstrate that Cd perturbs the DNA methylation status through the involvement of a specific methyltransferase. Such changes are linked to nuclear chromatin reconfiguration likely to establish a new balance of expressed/repressed chromatin. Overall, the data show an epigenetic basis to the mechanism underlying Cd toxicity in plants.