Effects of indoleacetic acid on the quantity of mitochondria, microbodies, and plastids in the apical and expanding cells of dark-grown oat coleoptiles

Journal Article · Fri Dec 31 23:00:00 EST 1976 · Plant Physiol.; (United States)

DOI:https://doi.org/10.1104/pp.60.2.323· OSTI ID:6803595

Shen-Miller, J; Gawlik, S R

We determined the number of mitochondria, microbodies, and plastids in dark-grown oat (Avena sativa) coleoptiles following incubation in indoleacetic acid (IAA) for a period of 60 minutes at 6-minute intervals. In the apical outer epidermis of coleoptiles, the mitochondria increased from 31.4 to 35 per cell section with a 6-minute incubation in IAA, and this trend persisted over the 60-minute incubation. Neither the microbodies, plastids, nor the dictyosomes (Gawlik and Miller 1974 Plant Physiol. 54: 217-221) responded to the hormone. The apical parenchyma showed no change in quantity of any of the organelles including the dictyosomes during IAA incubation. The quick response of mitochondria in the coleoptile tip could be interpreted as an association of this organelle with hormone transport, growth, or perhaps with gravity perception. In the subapical expansion reion, IAA caused significant reductions of mitochondria, microbodies, and dictyosomes in the outer epidermis compared to the control, the timing of which preceded the IAA-induced elongation and of geotropism. The fast response of organelles in the various cells is probably a change in organelle volume rather than number. That microbodies show a response to the plant hormone in the permanently achlorophyllous epidermis indicates that these organelles, in addition to their peroxisomal functions in green leaves, also may have a growth regulation function. IAA treatment was without effect on the quantity of the various types of plastids (including the amyloplasts) in the different oat coleoptile cells.

• Research Organization: Argonne National Lab., IL
• OSTI ID: 6803595
• Journal Information: Plant Physiol.; (United States), Journal Name: Plant Physiol.; (United States) Vol. 60; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
550300 -- Cytology
551000 -- Physiological Systems
59 BASIC BIOLOGICAL SCIENCES
AZOLES
BIOLOGICAL EFFECTS
BODY
CELL CONSTITUENTS
CEREALS
COLEOPTILE
EPIDERMIS
EPITHELIUM
GRAMINEAE
GRASS
GROWTH
HETEROCYCLIC COMPOUNDS
HORMONES
INDOLES
MICROSOMES
MITOCHONDRIA
OATS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANOIDS
ORGANS
PLANT CELLS
PLANTS
PYRROLES
SKIN
TISSUES