Anna Maria Tagliasacchi

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The results are reported of autoradiographic analyses accomplished on roots ofCalystegia soldanella fed with a 2,5 mCi/l solution of3H-thymidine and a 10mCi/l solution of3H-uridine. Two regions of the meristem were investigated: cap-initial (CI) and quiescent center (QC). It is shown, in agreement with the literature data, that cap initials and quiescent(More)
The pattern of DNA and RNA puffs in pair VII of polytene chromosomes has been investigated in the suspensor ofPhaseolus coccineus during early embryo development. The pattern of3H-TdR and3H-U incorporation has been also detected. Collected data indicate that: 1. both heterochromatic regions, p11 and q(111+112), of chromosome pair VII, organize large DNA(More)
5-Methylcytosine (5-mC) has been visualized in polytene chromosomes of Phaseolus coccineus, scarlet bean using specific antibodies to 5-mC and the immunoperoxidase technique. The results obtained indicate that most heterochromatic regions are methylated, even though the frequency of methylation is highly variable and sometimes low. A preferential binding of(More)
The mitotic cycle in root apical meristems of mycorrhizal and non-mycorrhizal plants ofAllium porrum L.+Glomus sp., strain E3, has been examined by3H-TdR labelling. Significant slowing down of the mitotic cycle in the mycorrhizas through an extension of G1, S and metaphase was observed, while G2 was drastically reduced. Lengthening of the cycle was(More)
In the giant cells of thePhaseolus coccineus embryo suspensor the number of nucleoli is not constant during early embryogenesis. Over the same period the number and the type of chromosomes involved in the nucleolar organization also vary. Moreover, the percentage of DNA and RNA puffs organized by ribosomal cistron (rc) bearing regions changes. When single(More)
BACKGROUND AND AIMS Plant adaptation to submergence can include the formation of prominent aerenchyma to facilitate gas exchange. The aim of this study was to characterize the differentiation of the constitutive aerenchyma in the stem of the aquatic macrophyte Egeria densa (Hydrocharitaceae) and to verify if any form of cell death might be involved. (More)
DNA was extracted from etiolated plantlets ofPhaseolus coccineus L. and studied by means of thermal denaturation and reassociation kinetics and CsCl analytical ultracentrifugation. A DNA fraction reassociating within an equivalent Cot of 1.15 × 10−1 (fast renaturing DNA sequences; FRS) was found to constitute 20.8% of the total DNA, 6.8% of which is(More)
Arbuscular mycorrhizal (AM) fungi significantly improve plant growth in soils with low phosphorus availability and cause many changes in root morphology, similar to those produced by increased P nutrition, mainly depending on root apex size and activity. The aim of this work was to discriminate between the morphogenetic role of AM fungi and P in leek(More)
On the assumption that arsenic induces stress morphogenetic responses involved in As tolerance and hyperaccumulation in the Pteris vittata fern, we analyzed the root system of young sporophytes grown in 250, 334, and 500 μM As for five days and for 14 days. Anatomical and histological analyses were performed in plants grown for five days to evaluate the(More)
When exposed to an acute ozone stress, cell death occurred in leaves of the O3 sensitive Populus deltoides × maximowiczii clone Eridano. After treatment (5 h fumigation and 24 h recovery), the damaged areas covered more than 50 % of the leaf surface. At cellular level, these lesions were preceded by some apoptotic hallmarks and by biochemical and(More)