Regions of differential cell elongation and mitosis, and root meristem morphology in different tissues of geotropically stimulated maize root apices

Journal Article · Sun Jan 01 04:00:00 EST 1978 · Plant Physiol.; (United States)

DOI:https://doi.org/10.1104/pp.61.1.7· OSTI ID:5114454

Shen-Miller, J; McNitt, R E; Wojciechowski, M

We examined cell length, mitosis, and root meristem ''cuticle'' in different tissues of geostimulated, red light-exposed pimary roots on corn (Zea Mays, Wisconsin hybrid 64A x 22R). The examination was done at 15-minute intervals for a period of 240 minutes. Differences in cell elongation between the upper and lower sides were most prominent between 1.5 and 2.5 mm from the root meristem; the outer cortex had the greatest elongation growth, and the upper cells showed a significant increase in length compared to the lower. A differential mitosis was also found, with the lower tissue being greater. We infer that the mitotic activity is indicative of cell division, and this division occurs strictly in the first 1.5 mm of the root meristem. The combined effect of differential cell elongation and cell division results in the localization of the geotropic curvature in the 1.5- to 2.5-mm region from the root meristem. Mitosis that occurs primarily in the cortex and stele were asynchronous; the peak of cortical division preceded that of the stele. Both peaks occurred before the peak of geotropism. A densely stained layer separates the cap from the root meristem. This layer is thinner at the apex of the root meristem. The area of the thin region increased with time and peaked at 180 minutes after geostimulation, which was coincidental with the peak of the geotropic response.

• Research Organization: Argonne National Lab., IL
• OSTI ID: 5114454
• Journal Information: Plant Physiol.; (United States), Journal Name: Plant Physiol.; (United States) Vol. 61:1; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

550300* -- Cytology
59 BASIC BIOLOGICAL SCIENCES
BIOMASS
CELL DIVISION
CEREALS
ENERGY SOURCES
GRAMINEAE
GRASS
GROWTH
MAIZE
MITOSIS
MORPHOLOGY
PLANT CELLS
PLANT TISSUES
PLANTS
RENEWABLE ENERGY SOURCES
ROOTS