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CHARACTERIZATION OF DEVELOPMENT IN MAIZE THROUGH THE USE OF MUTANTS. II. THE ABNORMAL GROWTH CONDITIONED BY THE KNOTTED MUTANT
Author(s) -
Gelinas D.,
Postlethwait S. N.,
Nelson O. E.
Publication year - 1969
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1969.tb07584.x
Subject(s) - biology , meristem , elongation , mutant , cell division , botany , knot (papermaking) , anatomy , cell , genetics , shoot , gene , engineering , metallurgy , ultimate tensile strength , materials science , chemical engineering
The maize mutant Knotted (Kn) is characterized by hollow, finger‐like outgrowths (knots) occurring mainly in the leaf blade. Portions of the ligule are displaced from the normal position to more distal locations within the blade. Knots apparently result from continued meristematic activity of isolated patches of cells surrounded by maturing tissue. Small knots appear to be centers of cell division. Epidermal cells overlying a small knot have been observed to undergo periclinal divisions. In addition to cell division, a reorientation of the axis of cell elongation is associated with knot formation. The pattern of knot distribution varies at different levels on the plant axis and within a leaf blade. From leaf 4 to leaf 10 or 11 the number of knots per leaf increases progressively, then declines in leaves initiated later. Knots always occur in association with lateral veins. The greatest number per vein occurs on the 3rd or 4th vein from the midrib. One plant developing from an X‐rayed heterozygous seed possessed a sector of normal tissue bisecting the plant in a vertical plane passing through the midrib of each leaf except the top two. The normal sector was knot‐free and had the ligule restored to the normal position. These observations suggest that cells with the characteristics of those from intercalary meristems occur throughout the blade in Knotted plants.