Development and ultrastructure of the endodermis in the primary root of cork oak (Quercus suber)

1997 ◽  
Vol 75 (5) ◽  
pp. 769-780 ◽  
Author(s):  
Dolors Verdaguer ◽  
Marisa Molinas
Keyword(s):  
Chemical Nature ◽  
Primary Root ◽  
Quercus Suber ◽  
Cork Oak ◽  
Maturation Process ◽  
Cortical Cells ◽  
Casparian Strip ◽  
Maturation Stages ◽  
Histochemical Tests

The endodermis maturation process was studied in the primary root of the cork oak (Quercus suber L.) with emphasis on the chemical nature of the cell wall and on the possible role of tannins. Tannins were found in endodermal and adjacent cortical cells in all maturation stages. We discuss our findings in relation to the previous literature in other woody and herbaceous species. The results of the histochemical tests showed differences in the aliphatic compounds of the suberin between the Casparian strip suberin and the suberin layer deposited in state II cells. Plasmodesmata were present in radial and tangential walls during the entire maturation process. The significance of plasmodesmata and of the suberin deposition pattern is discussed in relation to apoplastic and symplastic transport in roots. Key words: Casparian strip, endodermis, primary root, suberin, Quercus suber L.

scholarly journals Chemical Composition of Cuticular Waxes and Pigments and Morphology of Leaves of Quercus suber Trees of Different Provenance

Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1165
Author(s):  
Rita Simões ◽  
Ana Rodrigues ◽  
Suzana Ferreira-Dias ◽  
Isabel Miranda ◽  
Helena Pereira
Keyword(s):  
Chemical Composition ◽  
Photosynthetic Pigment ◽  
Leaf Size ◽  
Bioactive Compound ◽  
Leaf Traits ◽  
Quercus Suber ◽  
Cork Oak ◽  
Cuticular Waxes ◽  
Dark Green

The chemical composition of cuticular waxes and pigments and the morphological features of cork oak (Quercus suber) leaves were determined for six samples with seeds of different geographical origins covering the natural distribution of the species. The leaves of all samples exhibited a hard texture and oval shape with a dark green colour on the hairless adaxial surface, while the abaxial surface was lighter, with numerous stomata and densely covered with trichomes in the form of stellate multicellular hairs. The results suggest an adaptive role of leaf features among samples of different provenance and the potential role of such variability in dealing with varying temperatures and rainfall regimes through local adaptation and phenotypic plasticity, as was seen in the trial site, since no significant differences in leaf traits among the various specimens were found, for example, specific leaf area 55.6–67.8 cm2/g, leaf size 4.6–6.8 cm2 and photosynthetic pigment (total chlorophyll, 31.8–40.4 µg/cm2). The leaves showed a substantial cuticular wax layer (154.3–235.1 µg/cm2) composed predominantly of triterpenes and aliphatic compounds (61–72% and 17–23% of the identified compounds, respectively) that contributed to forming a nearly impermeable membrane that helps the plant cope with drought conditions. These characteristics are related to the species and did not differ among trees of different seed origin. The major identified compound was lupeol, indicating that cork oak leaves may be considered as a potential source of this bioactive compound.

scholarly journals The Arabidopsis TETRATRICOPEPTIDE THIOREDOXIN-LIKE 1 Gene Is Involved in Anisotropic Root Growth during Osmotic Stress Adaptation

Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 236
Author(s):  
María Belén Cuadrado-Pedetti ◽  
Inés Rauschert ◽  
María Martha Sainz ◽  
Vítor Amorim-Silva ◽  
Miguel Angel Botella ◽  
...  
Keyword(s):  
Osmotic Stress ◽  
Root Growth ◽  
Cell Walls ◽  
Primary Root ◽  
Stress Adaptation ◽  
Elongation Zone ◽  
Cortical Cells ◽  
Force Microscopy ◽  
Atomic Force ◽  
The Mean

Mutations in the Arabidopsis TETRATRICOPEPTIDE THIOREDOXIN-LIKE 1 (TTL1) gene cause reduced tolerance to osmotic stress evidenced by an arrest in root growth and root swelling, which makes it an interesting model to explore how root growth is controlled under stress conditions. We found that osmotic stress reduced the growth rate of the primary root by inhibiting the cell elongation in the elongation zone followed by a reduction in the number of cortical cells in the proximal meristem. We then studied the stiffness of epidermal cell walls in the root elongation zone of ttl1 mutants under osmotic stress using atomic force microscopy. In plants grown in control conditions, the mean apparent elastic modulus was 448% higher for live Col-0 cell walls than for ttl1 (88.1 ± 2.8 vs. 16.08 ± 6.9 kPa). Seven days of osmotic stress caused an increase in the stiffness in the cell wall of the cells from the elongation zone of 87% and 84% for Col-0 and ttl1, respectively. These findings suggest that TTL1 may play a role controlling cell expansion orientation during root growth, necessary for osmotic stress adaptation.

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