Promotion of leaf sheath growth by gibberellic acid in a dwarf mutant of rice

The mechanism of gibberellin (GA)-induced leaf sheath growth was examined using a dwarf mutant of rice (Oryza sativa L. cv. Tan-ginbozu) treated in advance with an inhibitor of GA biosynthesis. Gibberellic acid (GA3) enhanced the growth of the second leaf sheath, but auxins did not. Measurement of t...

Full description

Saved in:
Bibliographic Details
Published in:Planta 1998-06, Vol.205 (2), p.145-152
Main Authors: Matsukura, C, Itoh, S, Nemoto, K, Tanimoto, E, Yamaguchi, J
Format: Article
Language:English
Subjects:
Agronomy. Soil science and plant productions
Auxins
Biological and medical sciences
biosynthesis
carbohydrate metabolism
cell division
Cell growth
Cell walls
Chemical agents
dwarfing
Economic plant physiology
Fundamental and applied biological sciences. Psychology
gibberellic acid
Gibberellins
growth
Growth and development
Leaf sheaths
length
mitosis
Morphogenesis, differentiation, rhizogenesis, tuberization. Senescence
mutants
Oryza sativa
osmosis
Plant cells
Plant physiology and development
Plants
Rice
sap
Seedlings
starch
Starches
Vegetative apparatus, growth and morphogenesis. Senescence
volume
water uptake
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The mechanism of gibberellin (GA)-induced leaf sheath growth was examined using a dwarf mutant of rice (Oryza sativa L. cv. Tan-ginbozu) treated in advance with an inhibitor of GA biosynthesis. Gibberellic acid (GA3) enhanced the growth of the second leaf sheath, but auxins did not. Measurement of the mitotic index and cell size revealed that cell elongation rather than cell division is promoted by GA3. Gibberellic acid increased the extensibility of cell walls in the elongation zone of the leaf sheath. It also increased the total amount of osmotic solutes including sugars in the leaf sheath, but did not increase the osmotic concentration of the cell sap, due to an accompanying increase in cell volume by water absorption. In the later stage of GA3-induced growth, starch granules completely disappeared from leaf sheath cells, whereas dense granules remained in control plants. These findings indicate that GA enhances cell elongation by increasing wall extensibility, osmotic concentration being kept unchanged by starch degradation.
ISSN:0032-0935
1432-2048
DOI:10.1007/s004250050306