scholarly journals Gibberellin and the Growth of Peach and Apricot Fruits

1968 ◽  
Vol 21 (2) ◽  
pp. 209 ◽  
Author(s):  
D I Jackson
Keyword(s):  
Cell Division ◽  
Growth Phase ◽  
Cell Expansion ◽  
Full Bloom ◽  
Gibberellin Level ◽  
Gibberellin Activity

Levels of gibberellin in purified extracts from developing peach fruits were compared with rates of cell division and cell expansion in the fruit tissues. No gibberellin was found in the ovary before full bloom. Immediately after full bloom gibberellin activity was found in the seed, and later in the mesocarp and endocarp as well. Gibberellin concentration was closely correlated with the rate of cell expansion in each tissue, but not with cell division. Until the final growth phase, when activity was found only in the mesocarp, the highest gibberellin level was always found in the seed.

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

2004 ◽  
Vol 129 (1) ◽  
pp. 37-41 ◽  
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).

scholarly journals Physiology regulates the relationship between coccosphere geometry and growth phase in coccolithophores

2017 ◽  
Vol 14 (6) ◽  
pp. 1493-1509 ◽  
Author(s):  
Rosie M. Sheward ◽  
Alex J. Poulton ◽  
Samantha J. Gibbs ◽  
Chris J. Daniels ◽  
Paul R. Bown
Keyword(s):  
Cell Division ◽  
Environmental Change ◽  
Growth Phase ◽  
Fossil Record ◽  
Phase Shifts ◽  
Cell Physiology ◽  
Nutrient Depletion ◽  
Growth Responses ◽  
Growth Phases ◽  
Phytoplankton Group

Abstract. Coccolithophores are an abundant phytoplankton group that exhibit remarkable diversity in their biology, ecology and calcitic exoskeletons (coccospheres). Their extensive fossil record is a testament to their important biogeochemical role and is a valuable archive of biotic responses to environmental change stretching back over 200 million years. However, to realise the full potential of this archive for (palaeo-)biology and biogeochemistry requires an understanding of the physiological processes that underpin coccosphere architecture. Using culturing experiments on four modern coccolithophore species (Calcidiscus leptoporus, Calcidiscus quadriperforatus, Helicosphaera carteri and Coccolithus braarudii) from three long-lived families, we investigate how coccosphere architecture responds to shifts from exponential (rapid cell division) to stationary (slowed cell division) growth phases as cell physiology reacts to nutrient depletion. These experiments reveal statistical differences in coccosphere size and the number of coccoliths per cell between these two growth phases, specifically that cells in exponential-phase growth are typically smaller with fewer coccoliths, whereas cells experiencing growth-limiting nutrient depletion have larger coccosphere sizes and greater numbers of coccoliths per cell. Although the exact numbers are species-specific, these growth-phase shifts in coccosphere geometry demonstrate that the core physiological responses of cells to nutrient depletion result in increased coccosphere sizes and coccoliths per cell across four different coccolithophore families (Calcidiscaceae, Coccolithaceae, Isochrysidaceae and Helicosphaeraceae), a representative diversity of this phytoplankton group. Building on this, the direct comparison of coccosphere geometries in modern and fossil coccolithophores enables a proxy for growth phase to be developed that can be used to investigate growth responses to environmental change throughout their long evolutionary history. Our data also show that changes in growth rate and coccoliths per cell associated with growth-phase shifts can substantially alter cellular calcite production. Coccosphere geometry is therefore a valuable tool for accessing growth information in the fossil record, providing unprecedented insights into the response of species to environmental change and the potential biogeochemical consequences.

Could the extent of cell division, cell expansion and endoreduplication in a leaf be controlled by leaf expansion itself?

2009 ◽  
Vol 153 (2) ◽  
pp. S175
Author(s):  
Christine Granier ◽  
Sébastien Tisné ◽  
Catherine Massonnet ◽  
Juliette Fabre ◽  
Nathalie Wuyts ◽  
...  
Keyword(s):  
Cell Division ◽  
Cell Expansion ◽  
Leaf Expansion ◽  
Division Cell

scholarly journals Spatial differences in stoichiometry of EGR phosphatase and Microtubule-Associated Stress Protein 1 control root meristem activity during drought stress.

2021 ◽  
Author(s):  
Toshisagba Longkumer ◽  
Chih-Yun Chen ◽  
Marco Biancucci ◽  
Bhaskara Govinal Badiger ◽  
Paul E. Verslues
Keyword(s):  
Cell Division ◽  
Cell Size ◽  
Cell Expansion ◽  
Growth Regulation ◽  
Root Meristem ◽  
Stress Protein ◽  
Root Cell ◽  
Root Cortex ◽  
Meristem Cell ◽  
Meristem Size

During moderate severity drought and low water potential (Ψw) stress, poorly understood signaling mechanisms restrict both meristem cell division and subsequent cell expansion. We found that the Clade E Growth-Regulating 2 (EGR2) protein phosphatase and Microtubule Associated Stress Protein 1 (MASP1) differed in their stoichiometry of expression across the root meristem and had opposing effects on root meristem activity at low Ψw. Ectopic MASP1 or EGR expression increased or decreased, respectively, root meristem size and root elongation during low Ψw stress. This, along with the ability of phosphomimic MASP1 to overcome EGR suppression of root meristem size and observation that ectopic EGR expression had no effect on unstressed plants, indicated that during low Ψw EGR activation and attenuation of MASP1 phosphorylation in their overlapping zone of expression determines root meristem size and activity. Ectopic EGR expression also decreased root cell size at low Ψw. Conversely, both the egr1-1egr2-1 and egr1-1egr2-1masp1-1 mutants had similarly increased root cell size; but, only egr1-1egr2-1 had increased cell division. These observations demonstrated that EGRs affect meristem activity via MASP1 but affect cell expansion via other mechanisms. Interestingly, EGR2 was highly expressed in the root cortex, a cell type important for growth regulation and environmental response.

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