Benzyladenine Effects on Cell Division and Cell Size during Apple Fruit Thinning

Benzyladenine (BA), carbaryl (CB), daminozide (DM), and naphthaleneacetic acid (NAA) were applied postbloom, as fruitlet thinning agents, to mature `Empire' apple trees. Although fruit set and yield were similar for BA, NAA, and CB, BA-treated fruit were larger, indicating BA increased fruit size beyond the effect attributable to thinning. BA applied at 100 mg·liter–1 increased the rate of cell layer formation in the fruit cortex, indicating that BA stimulated cortical cell division. The maximum rate of cell division occurred 10 to 14 days after full bloom (DAFB) when fruit relative growth rate and density reached a maximum and percent dry weight reached a minimum. Cell size in BA-treated fruit was similar to the control. Cell division ended by 35 DAFB in the control and BA-treated fruit when percent dry weight and dry weight began to increase rapidly and fruit density changed from a rapid to a slower rate of decreased density. These data support the hypothesis that BA-induced fruit size increases in `Empire' apple result largely from greater numbers of cells in the fruit cortex, whereas the fruit size increase due to NAA or CB is a consequence of larger cell size.

Download Full-text

Benzyladenine Affects Cell Division and Cell Size during Apple Fruit Thinning

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.120.5.802 ◽

1995 ◽

Vol 120 (5) ◽

pp. 802-807 ◽

Cited By ~ 42

Author(s):

Paul T. Wismer ◽

J.T.A. Proctor ◽

D.C. Elfving

Keyword(s):

Cell Division ◽

Cell Size ◽

Fruit Set ◽

Fruit Size ◽

Cortical Cell ◽

Size Increase ◽

Cell Diameter ◽

Naphthaleneacetic Acid ◽

Division Rate ◽

Return Bloom

Benzyladenine (BA), carbaryl (CB), daminozide (DM), and naphthaleneacetic acid (NAA) were applied postbloom as fruitlet thinning agents to mature `Empire' apple (Malus domestica Borkh.) trees. BA, NAA, and CB reduced fruit set and yield per tree, and increased fruit size, percent dry weight, soluble solidscontent and return bloom. Fruit size was reduced, return bloom, length: diameter ratio and flesh firmness were increased, and fruit set and yield unaltered by DM. Although fruit set and yield were similar for BA, NAA, and CB, BA treated fruit were larger, indicating that BA increased fruit size beyond the effect attributable to chemical thinning alone. BA increased the rate of cell layer formation in the fruit cortex, indicating that BA stimulated cortical cell division. NAA, CB and DM had no effect on cell division rate. Mean cortical cell diameter at harvest was increased by NAA and CB and reduced by DM. Cell diameter at harvest in BA-treated fruit was similar to the control. These data support the hypothesis that BA-induced fruit size increase in `Empire' apple results from greater numbers of cells in the fruit cortex, whereas the fruit size increase due to NAA or CB is a consequence of larger cell size. Chemical names used: N-(phenylmethyl)-1H-purine-6-amine [benzyladenine (BA)]; 1-napthaleneacetic acid (NM); 1-naphthalenyl methylcarbamate [carbaryl (CB)]; butanedioic acid mono (2,2dimethyl hydrazide) [daminozide (DM)].

Download Full-text

682 New Perspectives on the Influence of Mid-season Environment on Apple Fruit Characteristics

HortScience ◽

10.21273/hortsci.35.3.516c ◽

2000 ◽

Vol 35 (3) ◽

pp. 516C-516

Author(s):

D.S. Tustin ◽

T. Fulton ◽

H. Brown

Keyword(s):

Cell Division ◽

Fruit Development ◽

Climatic Variability ◽

Fruit Size ◽

Cortical Cell ◽

Dry Weight ◽

Apple Fruit ◽

Major Influence ◽

Controlled Environment ◽

Crop Load

Growth of apple fruit can be described as an initial exponential phase lasting the 40+ days of fruit cell division followed by a more-or-less linear phase where growth is by cell expansion. Temperature is a major influence on fruit growth rate during the cell division phase, thereby affecting fruit size at maturity. However it is generally thought that temperature has less-direct impact on fruit development during the fruit expansion phase. Our observations of apple growth among regions and seasons of considerable climatic variability led us to speculate that temperature may impact directly on fruit development during fruit expansion but that responses may be interactive with carbon balance (crop load) influences. Controlled environment studies are being used to examine this hypothesis. Potted `Royal Gala' trees set to three levels of crop (one fruit per 250, 500, or 1000 cm2 leaf area) were grown from 56 to 112 DAFB in day/night temperature regimes of 18/6, 24/12, and 30/18 °C. All trees grew in field conditions prior to and following the controlled environment treatments. Treatments were harvested when 20% to 25% of fruit on trees showed the visual indicators used commercially to indicate harvest maturity. Fruit were evaluated using attributes that determine quality and that may have implications for fruit post harvest behaviour. Temperature and crop load influences on time to maturity, fruit fresh and dry weight, fruit DM content, fruit firmness, fruit airspace content and estimated fruit cortical cell size will be presented and implications discussed.

Download Full-text

DEVELOPMENTAL STUDIES OF THE APPLE FRUIT IN THE VARIETIES McINTOSH RED AND WAGENER: II. AN ANALYSIS OF DEVELOPMENT

Canadian Journal of Research ◽

10.1139/cjr41c-037 ◽

1941 ◽

Vol 19c (10) ◽

pp. 371-382 ◽

Cited By ~ 6

Author(s):

Mary MacArthur ◽

R. H. Wetmore

Keyword(s):

Cell Division ◽

Cell Size ◽

Fruit Size ◽

Apple Fruit ◽

Vascular Bundles ◽

Developmental Studies ◽

Cell Enlargement ◽

Ground Tissue ◽

Fundamental Pattern

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.

Download Full-text

CDK control pathways integrate cell size and ploidy information to control cell division

eLife ◽

10.7554/elife.64592 ◽

2021 ◽

Vol 10 ◽

Author(s):

James Oliver Patterson ◽

Souradeep Basu ◽

Paul Rees ◽

Paul Nurse

Keyword(s):

Cell Cycle ◽

Cell Division ◽

Cell Size ◽

Control Cell ◽

Size Information ◽

Inhibitory Tyrosine Phosphorylation ◽

Dependent Inhibition ◽

Control Cell Division ◽

Diploid Cells

Maintenance of cell size homeostasis is a property that is conserved throughout eukaryotes. Cell size homeostasis is brought about by the co-ordination of cell division with cell growth, and requires restriction of smaller cells from undergoing mitosis and cell division, whilst allowing larger cells to do so. Cyclin-CDK is the fundamental driver of mitosis and therefore ultimately ensures size homeostasis. Here we dissect determinants of CDK activity in vivo to investigate how cell size information is processed by the cell cycle network in fission yeast. We develop a high-throughput single-cell assay system of CDK activity in vivo and show that inhibitory tyrosine phosphorylation of CDK encodes cell size information, with the phosphatase PP2A aiding to set a size threshold for division. CDK inhibitory phosphorylation works synergistically with PP2A to prevent mitosis in smaller cells. Finally, we find that diploid cells of equivalent size to haploid cells exhibit lower CDK activity in response to equal cyclin-CDK enzyme concentrations, suggesting that CDK activity is reduced by increased DNA levels. Therefore, scaling of cyclin-CDK levels with cell size, CDK inhibitory phosphorylation, PP2A, and DNA-dependent inhibition of CDK activity, all inform the cell cycle network of cell size, thus contributing to cell-size homeostasis.

Download Full-text

Response of Several Apple Cultivars to Thinning Sprays of Benzyladenine, NAA, Carbaryl, and Combinations Thereof

HortScience ◽

10.21273/hortsci.30.4.765f ◽

1995 ◽

Vol 30 (4) ◽

pp. 765F-765

Author(s):

F.G. Dennis

Keyword(s):

Fruit Size ◽

Apple Fruit ◽

Naphthaleneacetic Acid ◽

Crop Load ◽

Fruit Thinning ◽

Apple Cultivars ◽

General Response

In 1994, benzyladenine (BA, formulated as Accel, containing 1.8% BA and 0.18% GA4+7) was evaluated as an apple fruit-thinning agent. Naphthaleneacetic acid (NAA, 10 ppm) and carbaryl (60 g·liter–1) were also used, as well as combinations of these chemicals with BA. Whole trees were treated with either an airblast sprayer or a hand gun, BA being used at 15–20 g/acre. Good responses to BA were obtained in one of two trials, with both `Empire' and `Gala', but `Jonagold' and `Jonathan' were not responsive (one trial each). In general, response to NAA and carbaryl was more consistent. In only one orchard (`Gala') did BA appear to increase fruit size without reducing crop load. Combinations of BA with NAA or carbaryl were generally no more effective than one chemical alone, but such combinations overthinned in one experiment with `Empire'.

Download Full-text

Rootstock Effects on Growth, Cell Number, and Cell Size of `Gala' Apples

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.129.1.0037 ◽

2004 ◽

Vol 129 (1) ◽

pp. 37-41 ◽

Cited By ~ 6

Author(s):

Yahya K. Al-Hinai ◽

Teryl R. Roper

Keyword(s):

Cell Division ◽

Cell Size ◽

Agricultural Research ◽

Fruit Size ◽

Cell Number ◽

Fruit Growth ◽

Research Station ◽

Full Bloom ◽

Final Size ◽

Load Effects

The effects of rootstock on growth of fruit cell number and size of `Gala' apple trees (Malus domestica Borkh) were investigated over three consecutive seasons (2000-02) growing on Malling 26 (M.26), Ottawa-3, Pajam-1, and Vineland (V)-605 rootstocks at the Peninsular Agricultural Research Station near Sturgeon Bay, WI. Fruit growth as a function of cell division and expansion was monitored from full bloom until harvest using scanning electron microscopy (SEM). Cell count and cell size measurements showed that rootstock had no affect on fruit growth and final size even when crop load effects were removed. Cell division ceased about 5 to 6 weeks after full bloom (WAFB) followed by cell expansion. Fruit size was positively correlated (r2 = 0.85) with cell size, suggesting that differences in fruit size were primarily a result of changes in cell size rather than cell number or intercellular space (IS).

Download Full-text

Partitioning of symbiotic Chlorella at host cell telophase in the green hydra symbiosis

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.1990.0148 ◽

1990 ◽

Vol 329 (1252) ◽

pp. 47-53 ◽

Cited By ~ 6

Keyword(s):

Cell Division ◽

Host Cell ◽

Daughter Cell ◽

Control Cell ◽

Culture Conditions ◽

Digestive Cells ◽

Density Dependent ◽

Green Hydra ◽

The Mean ◽

Control Cell Division

Although there is much evidence that green hydra digestive cells control cell division of their Chlorella symbionts, so that the symbionts divide only at host cell division, it is not clear how the population size of symbionts (numbers per cell) is regulated. In constant culture conditions the mean number of symbionts per cell also remains constant, but with a very large variance about the mean. The way in which symbionts are partitioned at host cell division appears to account for that variation. By counting numbers of Chlorella in daughter cells at late telophase it was found that partitioning of Chlorella symbionts was not symmetrical, but at random, closely following that predicted by the binomial distribution if it is assumed that each symbiont had an equal probability of entering either host daughter cell. A better fit to the predicted distribution was obtained from observations of partition in digestive cells from excised regenerating peduncles than in those from recently fed gastric regions, possibly because in the former, algae have completed their division before the host cell divides, while in the latter algal and host cell division takes place at the same time. There was only a small effect of differences in daughter cell volume on numbers of symbionts received, but comparison of variance and coefficient of variation of numbers of algae in mother (post-algal division, pre-partition) and daughter telophase digestive cells (pre-division, post-partition) suggested that algal division at host mitosis was density dependent. Random partitioning of algae at host cell telophase would account for the wide variation in numbers of algae per cell, and compensatory density-dependent algal division at the next host cell mitosis would ensure stability of the mean algal population.

Download Full-text