Regulation of Leaf Form in Centaurea solstitialis L. I. Leaf Development on Whole Plants in Sterile Culture

1970 ◽  
Vol 131 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Lewis J. Feldman ◽  
Elizabeth G. Cutter
Keyword(s):  
Leaf Development ◽  
Centaurea Solstitialis ◽  
Leaf Form ◽  
Sterile Culture ◽  
Whole Plants

Heteroblastic seedlings of green ash. I. Predictability of leaf form and primordial length

1986 ◽  
Vol 64 (11) ◽  
pp. 2645-2649 ◽  
Author(s):  
E. K. Merrill
Keyword(s):  
Leaf Development ◽  
Leaf Growth ◽  
Leaf Primordia ◽  
Fraxinus Pennsylvanica ◽  
Green Ash ◽  
Leaf Form ◽  
Compound Leaf ◽  
Controlled Conditions ◽  
Plastochron Index

Green ash (Fraxinus pennsylvanica var. subintegerrima) seedlings are heteroblastic; during development they produce two types of leaves, simple and compound. When grown under controlled conditions, the sequence of leaf types is predictable. Simple leaves are always at the first four nodes; compound leaves are always at node 8 and above. Nodes 5 through 7 have progressively fewer simple leaves and more compound leaves. Leaf growth on seedlings meets the preconditions of the plastochron index and leaf plastochron index. These indices, as well as the length of single expanding leaves, can be used to predict lengths of leaf primordia at nodes 4 and 8 so that early, simple and compound leaf development can be compared in further studies of green ash.

Development of open and closed leaf sheaths in Festuca trachyphylla and Festuca rubra (Poaceae)

1992 ◽  
Vol 70 (7) ◽  
pp. 1417-1428 ◽  
Author(s):  
Youqi Liu ◽  
Nancy G. Dengler
Keyword(s):  
Cross Sections ◽  
Leaf Development ◽  
Small Diameter ◽  
Leaf Sheath ◽  
Festuca Rubra ◽  
Ground Tissue ◽  
Longitudinal Splitting ◽  
Mature Leaves ◽  
Whole Plants ◽  
Important Character

The development of the leaf sheaths in two species of Festuca, subgenus Festuca, Festuca trachyphylla (Hackel) Krajina with open leaf sheaths and Festuca rubra L. s.l. with closed leaf sheaths is compared to determine the developmental basis of this taxonomically important character. In both species serial cross sections of seedlings, scanning electron microscopy, and dissections of whole plants showed that a short tubular leaf base is formed early during the second plastochron of leaf development. Later during the same plastochron, ligule formation delimits sheath and blade; at this stage, the tubular portion occupies about one-half (200 – 500 μm) of the incipient leaf sheath. Differential extension growth of the distal open portion and proximal closed section of the sheath results in the primarily open or closed sheaths that characterize the mature leaves of the two species. The longitudinal splitting of the tubular leaf sheath in a position opposite the midvein in F. rubra is anticipated by a zone of small-diameter cells within the ground tissue, but no other structural correlates of sheath mechanical strength and persistence were detected. Our observations indicate that subtle shifts in the distribution of growth during leaf expansion result in the contrasting character states exemplified by these two species. Key words: Festuca, grass leaf development, leaf sheath, Poaceae.

scholarly journals Hsp70 plays a role in programmed cell death during the remodelling of leaves of the lace plant (Aponogeton madagascariensis)

2019 ◽  
Author(s):  
Nathan M Rowarth ◽  
Adrian N Dauphinee ◽  
Georgia L Denbigh ◽  
Arunika Hlan Gunawardena
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Leaf Development ◽  
Anthocyanin Content ◽  
Plant Leaves ◽  
Antioxidant Treatment ◽  
Plant Leaf ◽  
Whole Plants ◽  
Shock Proteins

Abstract Lace plant leaves utilize programmed cell death (PCD) to form perforations during development. The role of heat shock proteins (Hsps) in PCD during lace plant leaf development is currently unknown. Hsp70 amounts were measured throughout lace plant leaf development, and the results indicate that it is highest before and during PCD. Increased Hsp70 amounts correlate with raised anthocyanin content and caspase-like protease (CLP) activity. To investigate the effects of Hsp70 on leaf development, whole plants were treated with either of the known regulators of PCD [reactive oxygen species (ROS) or antioxidants] or an Hsp70 inhibitor, chlorophenylethynylsulfonamide (PES-Cl). ROS treatment significantly increased Hsp70 2-fold and CLP activity in early developing leaves, but no change in anthocyanin and the number of perforations formed was observed. Antioxidant treatment significantly decreased Hsp70, anthocyanin, and CLP activity in early leaves, resulting in the fewest perforations. PES-Cl (25 μM) treatment significantly increased Hsp70 4-fold in early leaves, while anthocyanin, superoxide, and CLP activity significantly declined, leading to fewer perforations. Results show that significantly increased (4-fold) or decreased Hsp70 amounts lead to lower anthocyanin and CLP activity, inhibiting PCD induction. Our data support the hypothesis that Hsp70 plays a role in regulating PCD at a threshold in lace plant leaf development. Hsp70 affects anthocyanin content and caspase-like protease activity, and helps regulate PCD during the remodelling of leaves of lace plant, Aponogeton madagascariensis.

The involvement of ethylene in programmed cell death and climacteric-like behaviour during the remodelling of lace plant (Aponogeton madagascariensis) leaves

Botany ◽  
2012 ◽  
Vol 90 (12) ◽  
pp. 1237-1244 ◽  
Author(s):  
A.N. Dauphinee ◽  
H. Wright ◽  
G. Rantong ◽  
A.H.L.A.N. Gunawardena
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Leaf Development ◽  
Inhibitory Effect ◽  
Ethylene Biosynthesis ◽  
Developmentally Regulated ◽  
Developmental Processes ◽  
Climacteric Fruit ◽  
Signalling Molecule ◽  
Whole Plants

Programmed cell death (PCD) plays an important role in several plant developmental processes. The phytohormone ethylene has been implicated in PCD signalling in many plant systems, but it is also important in developmental processes such as seed germination, flowering, and climacteric fruit ripening. Lace plant (Aponogeton madagascariensis (Mirbel) H. Bruggen) is an aquatic monocot that develops perforated leaves via the deletion of cells through developmentally regulated PCD. The plant is ideal for studying PCD; however, little is known about the regulation of cellular death involved in this system. The current study examines ethylene as a potential signalling molecule in lace plant PCD and investigates climacteric-like behaviour during lace plant leaf development. Whole plants were treated with the ethylene biosynthesis inhibitor aminoethoxyvinylglycine (AVG), the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC), or a combination of both. Subsequently, ethylene levels were monitored, and leaf development was analyzed. The results indicate that ethylene is involved in lace plant PCD signalling. AVG-treated plants had significantly lower ethylene outputs and a significant reduction in perforation formation. The inhibitory effect of AVG was recovered when AVG and ACC were applied simultaneously. The data presented here show for the first time, to our knowledge, climacteric-like behaviour during the remodelling of leaves.

Effects of carbamylcholine on chick embryo aggregate retina cell cultures

1988 ◽  
Vol 46 ◽  
pp. 350-351
Author(s):  
Glenn M. Cohen ◽  
Radharaman Ray
Keyword(s):  
Cell Cultures ◽  
Single Cells ◽  
Retinal Cell ◽  
Cell Aggregates ◽  
High Concentration ◽  
In Ovo ◽  
Sterile Culture ◽  
Retinal Tissue ◽  
Synaptic Junctions ◽  
And Control

Retinal,cell aggregates develop in culture in a pattern similar to the in ovo retina, forming neurites first and then synapses. In the present study, we continuously exposed chick retinal cell aggregates to a high concentration (1 mM) of carbamylcholine (carbachol), an acetylcholine (ACh) analog that resists hydrolysis by acetylcholinesterase (AChE). This situation is similar to organophosphorus anticholinesterase poisoning in which the ACh level is elevated at synaptic junctions due to inhibition of AChE, Our objective was to determine whether continuous carbachol exposure either damaged cholino- ceptive neurites, cell bodies, and synaptic elements of the aggregates or influenced (hastened or retarded) their development.The retinal tissue was isolated aseptically from 11 day embryonic White Leghorn chicks and then enzymatically (trypsin) and mechanically (trituration) dissociated into single cells. After washing the cells by repeated suspension and low (about 200 x G) centrifugation twice, aggregate cell cultures (about l0 cells/culture) were initiated in 1.5 ml medium (BME, GIBCO) in 35 mm sterile culture dishes and maintained as experimental (containing 10-3 M carbachol) and control specimens.

Freeze-Fracture Studies of Membranes in Developing Sieve Elements in a Plant Tissue Culture

1980 ◽  
Vol 38 ◽  
pp. 636-637
Author(s):  
R. D. Sjolund ◽  
C. Y. Shih
Keyword(s):  
Plant Tissue ◽  
Cultured Cells ◽  
Freeze Fracture ◽  
Tissue Cultures ◽  
Sieve Elements ◽  
Intact Plants ◽  
Plant Tissue Cultures ◽  
Whole Plants ◽  
Energy Dependent ◽  
Similar Elements

The differentiation of phloem in plant tissue cultures offers a unique opportunity to study the development and structure of sieve elements in a manner that avoids the injury responses associated with the processing of similar elements in intact plants. Short segments of sieve elements formed in tissue cultures can be fixed intact while the longer strands occuring in whole plants must be cut into shorter lengths before processing. While iyuch controversy surrounds the question of phloem function in tissue cultures , sieve elements formed in these cultured cells are structurally similar to those of Intact plants. We are particullarly Interested In the structure of the plasma membrane and the peripheral ER in these cells because of their possible role in the energy-dependent active transport of sucrose into the sieve elements.

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