The initiation of lateral roots in the primary roots of maize (Zea mays L.) implies a reactivation of cell proliferation in a group of founder pericycle cells

The exodermal Casparian band in corn (Zea mays L.) was first seen 10 mm distal to the kernel 4 days after planting. From its inception, the band usually occupied most of the radial wall (as seen in a cross section of the root). Subsequent maturation of the band around the root was asynchronous into the region of emerging lateral roots. Thus, a continuous apoplastic barrier would have been absent over much of the young root surface. Suberin lamellae development was also asynchronous, as these structures formed in those cells which had Casparian bands. Frequently, a lamella was initially deposited in patches, progressing centripetally until a continuous lipid layer was formed around the cell protoplast. Many instances of band plasmolysis (typical of the endodermis) were observed in the developing uniform exodermis. It could occur in cells with no detectable Casparian bands, suggesting that the tight connection between the plasmalemma and the wall that causes this phenomenon is not due to hydrophobic attractions. The results are consistent with the idea that there are strong attractions between proteins of the membrane and wall in the region of the Casparian band. The tight connection between the plasmalemma and the wall was broken during the later stages of suberin lamella development. Key words: Zea mays L., Poaceae, band plasmolysis, exodermis, Casparian band, suberin lamella.

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Aluminum in corn plants: influence on growth and morpho-anatomy of root and leaf

Revista Brasileira de Ciência do Solo ◽

10.1590/s0100-06832013000100018 ◽

2013 ◽

Vol 37 (1) ◽

pp. 177-187 ◽

Cited By ~ 8

Author(s):

Michelli Fernandes Batista ◽

Ismar Sebastião Moscheta ◽

Carlos Moacir Bonato ◽

Marcelo Augusto Batista ◽

Odair José Garcia de Almeida ◽

...

Keyword(s):

Zea Mays ◽

Root Growth ◽

Plant Height ◽

Dry Matter ◽

Zea Mays L ◽

Lateral Roots ◽

Dry Weight ◽

Al Toxicity ◽

Limiting Factors ◽

Corn Plants

Aluminum (Al) toxicity is one of the most limiting factors for productivity. This research was carried out to assess the influence of Al nutrient solution on plant height, dry weight and morphoanatomical alterations in corn (Zea mays L.) roots and leaves. The experiment was conducted in a greenhouse with five treatments consisting of Al doses (0, 25, 75, 150, and 300 µmol L-1) and six replications. The solutions were constantly aerated, and the pH was initially adjusted to 4.3. The shoot dry matter, root dry matter and plant height decreased significantly with increasing Al concentrations. Compared to the control plants, it was observed that the root growth of corn plants in Al solutions was inhibited, there were fewer lateral roots and the development of the root system reduced. The leaf anatomy of plants grown in solutions containing 75 and 300 µmol L-1 Al differed in few aspects from the control plants. The leaf sheaths of the plants exposed to Al had a uniseriate epidermis coated with a thin cuticle layer, and the cells of both the epidermis and the cortex were less developed. In the vascular bundle, the metaxylem and protoxylem had no secondary walls, and the diameter of both was much smaller than of the control plants.

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Impact of soil compaction heterogeneity and moisture on maize (Zea mays L.) root and shoot development

Plant Soil and Environment ◽

10.17221/429-pse ◽

2008 ◽

Vol 54 (No. 12) ◽

pp. 509-519 ◽

Cited By ~ 8

Author(s):

B. Konôpka ◽

L. Pagès ◽

C. Doussan

Keyword(s):

Zea Mays ◽

Soil Moisture ◽

Soil Compaction ◽

Statistical Tests ◽

Lateral Roots ◽

Primary Root ◽

Leaf Biomass ◽

Fine Soil ◽

Primary Roots ◽

Primary And Lateral Roots

Soil compaction heterogeneity and water content are supposed to be decisive factors influencing plant growth. Our experiment focused on simulation of two soil moisture levels (0.16 and 0.19 g/g) plus two levels of clod proportion (30 and 60% volume) and their effects on root and leaf variables of maize (Zea mays L.). We studied number of primary and lateral roots as well as primary root length at the particular soil depths. Statistical tests showed that the decrease rate of the number of roots versus depth was significantly affected by the two studied factors (P < 0.01). Soil moisture and clod occurrence, interactively, affected leaf biomass (P = 0.02). Presence of clods modified root morphological features. Particularly, the diameter of primary roots in the clods was significantly higher than of those grown in fine soil (P < 0.01). For primary roots, which penetrated clods, branching density decreased considerably for the root segments located just after the clods (P = 0.01). Regarding their avoidance to clods and tortuosity, large differences were found between primary roots grown in the contrasting soil environments.

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Effects of crude extract of Microcystis aeruginosa Kütz.on germination, growth and chlorophyll content of Zea mays L.

Bangladesh Journal of Botany ◽

10.3329/bjb.v42i2.18033 ◽

2014 ◽

Vol 42 (2) ◽

pp. 295-300

Author(s):

Mostafa M El Sheekh ◽

Hanan M Khairy ◽

Rania El Shenody

Keyword(s):

Zea Mays ◽

Chlorophyll Content ◽

Microcystis Aeruginosa ◽

Crude Extract ◽

Zea Mays L ◽

Growth Parameters ◽

Lateral Roots ◽

Inhibitory Effect ◽

Pigment Contents ◽

Death Phase

Effects of crude extract of Microcystis aeruginosa containing microcystin-LR on the germination, growth and chlorophyll content of Zea mays was studied. Soaking of Z. mays seeds for 24 hrs in the cell-free medium during death phase of M. aeruginosa induced a significant reduction in root, shoot lengths, number of lateral roots, fresh and dry weights, leaf area and pigment contents. Soaking of Z. mays seeds for 24 hours in different concentrations of crude extracts of M. aeruginosa (100, 200, 300, 500 and 800 ?g dry cells/ml) from log phase showed inhibitory effect of growth parameters and germination. DOI: http://dx.doi.org/10.3329/bjb.v42i2.18033 Bangladesh J. Bot. 42(2): 295-300, 2013 (December)

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