Developmental studies of the stratification–germination process in sugar maple embryos

1985 ◽  
Vol 63 (5) ◽  
pp. 903-908 ◽  
Author(s):  
C. Y. Shih ◽  
E. B. Dumbroff ◽  
Carol A. Peterson

Changes in the anatomy, morphology, and stored food reserves of stratifying (5 °C) sugar maple embryos were followed from a strongly dormant state through germination. The correlation of cell division and cell elongation with radicle protrusion was also investigated. No morphological or anatomical changes were observed before first maturation of phloem elements on the 17th day of stratification. Mature xylem elements were first observed on day 37, and first germination was noted on day 38. Radicle protrusion was initiated by cell elongation, and cell division was not active for several days after emergence and a marked increase in lengths of the axes had occurred. Changes in amounts of protein, lipid, and starch were not observed during the stratification period, but mobilization of stored reserves was clearly evident with emergence of the radicles. Several of these key events appeared to be closely associated with previously described peaks and patterns of growth regulator activity.

2006 ◽  
Vol 50 (7) ◽  
pp. 487-497 ◽  
Author(s):  
Hiroaki Takeuchi ◽  
Teruko Nakazawa ◽  
Takeshi Okamoto ◽  
Mutsunori Shirai ◽  
Mitsuo Kimoto ◽  
...  

Weed Science ◽  
1972 ◽  
Vol 20 (3) ◽  
pp. 233-237 ◽  
Author(s):  
J. F. Stritzke ◽  
E. J. Peters

Microscopic examination of central and soft offset bulbs of wild garlic(Allium vinealeL.) at senescence of the parent plants in May and June revealed embryonic plants with numerous root primordia and four or five shoot primordia. Hardshell bulbs and aerial bulblets contained only one or two root primordia and three leaf primordia. The embryonic plants of central, soft offset, and hardshell bulbs elongated slowly during the after-ripening period. Rapid cell division, cell elongation, and initiation of new leaves took place after termination of the after-ripening period in all but the dormant hardshell bulbs. In November, new hardshell bulbs could be seen at the base of plants developed from central and soft offset bulbs.


1941 ◽  
Vol 19c (10) ◽  
pp. 371-382 ◽  
Author(s):  
Mary MacArthur ◽  
R. H. Wetmore

Growth in the various tissues of the fruit of a McIntosh Red and a Wagener tree, both self-pollinated, is compared. For several days succeeding pollination no increase in fruit size is apparent. Fertilization is followed by general cell division and cell enlargement. The period of cell division varies with the tissue and with the variety. Final cell size is reached first by the cells of those tissues near the centre of the apple. Impressed upon the fundamental pattern of growth is the localized activity of the primary vascular bundles, the cambia of which add cells to the ground tissue. Angulation in the Wagener is accentuated by this activity. With the exception of cells of the epidermis, final cell size is approximately equal in comparable regions of the two varieties. Differences in regional extent are due to differences in numbers of cells in that region.


1979 ◽  
Vol 57 (12) ◽  
pp. 1340-1344 ◽  
Author(s):  
Thompson Demetrio Pizzolato ◽  
David L. Regehr

An aqueous spray of 4-(2,4-dichlorophenoxy)butyric acid (2,4-DB) induces anatomical changes in young Glycine internodes. Four days after spraying, the first symptoms appear outside the cambium when the interfascicular parenchyma cells and the adjacent cortical parenchyma cells enlarge and divide in several planes. Four days later, the metaphloem parenchyma cells in many of the leaf traces undergo considerable periclinal cell division and extensive radial cell enlargement. The phloem parenchyma cells of the late metaphloem and first secondary phloem enlarge and divide in a less orderly fashion. Fifteen days after treatment, the cortical parenchyma is modified into a band of radially seriate cells above the protophloem fibers. Products of this cambium-like region convert the cortex into a callus-like tissue. The size of starch grains is reduced initially in the phloem and xylem and later in the cortex. It appears that the stimuli produced by 2,4-DB move into the internode via the metaphloem of leaf traces. Despite the rapid obliteration of conducting phloem by the 2,4-DB induced stimulation of phloem parenchyma, an accelerated differentiation of secondary phloem compensates for this loss.


2000 ◽  
Vol 122 (2) ◽  
pp. 327-336 ◽  
Author(s):  
Renato D. de Castro ◽  
André A.M. van Lammeren ◽  
Steven P.C. Groot ◽  
Raoul J. Bino ◽  
Henk W.M. Hilhorst

2014 ◽  
Vol 24 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Leah Rosental ◽  
Hiroyuki Nonogaki ◽  
Aaron Fait

AbstractSeed germination is regulated in a concerted manner that involves generating growth potential in the embryo to overcome the mechanical resistance of the endosperm. The wake-up call of a dry seed includes the reorganization of subcellular structures and the reactivation of metabolism in a dense, oxygen-poor environment. Pools of unbound metabolites and solutes produced by the degradation of storage reserves, including starch, proteins and oils, in the embryo can contribute to the generation of the embryo growth potential and radicle protrusion. Recent genomics studies have contributed a vast amount of data on protein, metabolite and gene transcript profiles during germination, which can be integrated to explore the seed metabolism from water imbibition to radicle protrusion. To what extent are free pools of metabolites relevant to the reorganization of seed metabolism? How is energy built to support embryo growth and radicle protrusion? Elucidating these fundamental questions in seed biology is the key to the understanding of the germination process. Here we have attempted to summarize the recent scientific knowledge to provide a comprehensive description of the ignition, reassembling and regulation of metabolism during seed germination.


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