Effects of root or shoot exposure before planting on the water relations, growth, and survival of Sitka spruce

1981 ◽  
Vol 11 (3) ◽  
pp. 703-709 ◽  
Author(s):  
M. P. Coutts
Keyword(s):  
Root System ◽  
Water Movement ◽  
Substantial Reduction ◽  
Sitka Spruce ◽  
Similar Reduction ◽  
Growth And Survival ◽  
Woody Root ◽  
Root Exposure ◽  
Increased Sensitivity ◽  
Drying Conditions

Sitka spruce (Piceasitchensis (Bong.) Carr.) seedlings were exposed either by the root or the shoot to drying conditions in a growthroom. Changes in leaf water potential (ψ1) and rate of water loss were determined and measurements were made on the moisture content (MC) of the shoot, woody root, and fine roots.Exposure of the root or shoot reduced the MC of all tissues measured and reduced ψ1. When the root was exposed, water moved from the shoot into the root system, but this water movement did not prevent a substantial reduction in the MC of the root system. The greatest reduction occurred in the fine roots. Exposure of the root caused a faster decrease in fine root MC than exposure of the shoot.Treated seedlings were planted in root observation boxes, and those which had been exposed by the roots to give ψ1 of −20 × 105 Pa were found to be under increased water stress when measured 12 days after planting indicating that water uptake had been impaired. Root exposure also reduced plant survival and the growth of roots and shoots of plants which survived. Although exposure of the shoot to give ψ1 of −20 × 105 Pa resulted in a similar reduction in total plant MC as exposure of the root, the treatment was not damaging in terms of growth or survival after planting. It is concluded that measurement of neither whole plant MC nor ψ1 prior to planting can show whether a plant has been subjected to damaging conditions. Root exposure of plants in different stages of growth indicated increased sensitivity to exposure the farther the plants were removed from dormancy.

Root System Fibrosity of Sitka Spruce Transplants: Relationship with Root Growth Potential

1990 ◽  
Vol 63 (1) ◽  
pp. 1-7 ◽  
Author(s):  
J. D. DEANS ◽  
C. LUNDBERG ◽  
M. G. R. CANNELL ◽  
M. B. MURRAY ◽  
L. J. SHEPPARD
Keyword(s):  
Root Growth ◽  
Root System ◽  
Sitka Spruce ◽  
Growth Potential ◽  
Root Growth Potential

The Effect of Salinity on Root Architecture in Forage Pea (Pisum sativum ssp. arvense L.)

2021 ◽  
Author(s):  
S. Acikbas ◽  
M.A. Ozyazici ◽  
H. Bektas
Keyword(s):  
Root System ◽  
Root Architecture ◽  
System Development ◽  
Shoot Biomass ◽  
Growth And Survival ◽  
Legume Crop ◽  
Root System Development ◽  
Randomized Design ◽  
Salinity Levels ◽  
Root And Shoot Biomass

Background: Plants face different abiotic stresses such as salinity that affect their normal development, growth and survival. Forage pea is an important legume crop for herbage production in ruminants. Its agronomy requires high levels of irrigation and fertilization. This study aimed to evaluate the effect of salinity on seedling root system development in forage pea under semi-hydroponics conditions.Methods: Different treatment of NaCl doses (0, 50, 100, 150, 200, 250 and 300 mM) on root architecture was investigated in two different forage pea cultivars (Livioletta and Ulubatlý) with contrasting root structures under controlled conditions. The experimental design was completely randomized design with three replications and nine plants per replication.Result: Salinity affects root and shoot development differently on these cultivars. Despite the salinity, Livioletta produced more shoot (0.71 g) and root biomass (0.30 g) compared to Ulubatlý (0.52 g and 0.25 g for Root and Shoot biomass, respectively) at 150 mM and all other salinity levels. Livioletta developed a better root system and tolerated salt to a higher dose than Ulubatlý. Understanding root system responses of forage pea cultivars may allow breeding and selecting salinity tolerant cultivars with better rooting potential.

The Growth of a Tree—A Metaphor for Reflecting on the Role of JRME

2014 ◽  
Vol 45 (4) ◽  
pp. 402-405
Author(s):  
Nerida F. Ellerton
Keyword(s):  
Education Research ◽  
Mathematics Education ◽  
Root System ◽  
Soil Nutrients ◽  
Tree Species ◽  
Natural World ◽  
Mathematics Education Research ◽  
Growth And Survival ◽  
Natural Landscapes

Research journals likeJRMEplay key roles through the publication of peerreviewed research, and it is through such publications that the field has the potential to grow. The metaphor of a growing tree is a useful one to explore in the context of mathematics education research. Growth in the natural world is generally multidimensional. A tree's growth is measured not only in terms of its height but also in terms of the girth of its trunk, the spread of its branches, and the development of a substantial root system, all of which are essential for the tree's continued growth and survival. Soil nutrients need to be replenished, and without sufficient moisture, growth is arrested, and the tree becomes stunted. Many of the most interesting natural landscapes include a range of tree species as well as supporting undergrowth.

scholarly journals Physiological Responses of Three Grapevine Cultivars to Partial Root Drying

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1011C-1011
Author(s):  
Said Ennahli ◽  
Sorkel Kadir
Keyword(s):  
Stomatal Conductance ◽  
Root System ◽  
Fruit Quality ◽  
Root Zone ◽  
Plant Root ◽  
Irrigation Management ◽  
Substantial Reduction ◽  
Growth Yield ◽  
Control Treatment ◽  
Plant Root System

Partial root-zone drying (PRD) irrigation management has been developed for grapevines as an efficient method to control excessive growth, improve fruit quality, and save water without compromising yield. PRD is based on knowledge of the mechanisms that control transpiration and requires slow dehydration of half of the plant root system, whereas the other half is irrigated. A study was conducted in the field to evaluate the effect of PRD on physiological characteristics, growth, yield, and fruit quality of three grape cultivars. The wetting and drying cycle of the PRD-vine root system is alternated on a 10–14 day schedule. Significant reduction in vigor was observed in treated plants compared with control plants. Root biomass was not affected, but fine roots significantly increased in PRD-treated plants, compared with that of the control. This contributed to the ability of PRD-treated plants to maintain leaf water potential similar to that of the control. Stomatal conductance of PRD plants was significantly reduced when compared with that of the control plants. Abscisic acid (ABA) concentration in leaves of PRD vines increased significantly when compared to the control vines. PRD treatment significantly increased yield and fruit quality when compared with the control treatment. PRD significantly increased water use efficiency (pruning weight per unit of water applied). This study shows that PRD stimulated ABA production in the drying roots, which caused reduction in stomatal conductance and transpiration rate, leading to a substantial reduction in vegetative growth without compromising yield and fruit quality.

scholarly journals Organization of the Electron Transfer Chain to Oxygen in the Obligate Human Pathogen Neisseria gonorrhoeae: Roles for Cytochromes c4 and c5, but Not Cytochrome c2, in Oxygen Reduction

2010 ◽  
Vol 192 (9) ◽  
pp. 2395-2406 ◽  
Author(s):  
Ying Li ◽  
Amanda Hopper ◽  
Tim Overton ◽  
Derrick J. P. Squire ◽  
Jeffrey Cole ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Neisseria Gonorrhoeae ◽  
Excess Oxygen ◽  
Growth And Survival ◽  
Electron Transfer Chain ◽  
Alternative Pathways ◽  
Cytochrome C2 ◽  
Increased Sensitivity ◽  
Electron Transfer Pathways ◽  
Transfer Chain

ABSTRACT Although Neisseria gonorrhoeae is a prolific source of eight c-type cytochromes, little is known about how its electron transfer pathways to oxygen are organized. In this study, the roles in the respiratory chain to oxygen of cytochromes c 2, c 4, and c 5, encoded by the genes cccA, cycA, and cycB, respectively, have been investigated. Single mutations in genes for either cytochrome c 4 or c 5 resulted in an increased sensitivity to growth inhibition by excess oxygen and small decreases in the respiratory capacity of the parent, which were complemented by the chromosomal integration of an ectopic, isopropyl-β-d-thiogalactopyranoside (IPTG)-inducible copy of the cycA or cycB gene. In contrast, a cccA mutant reduced oxygen slightly more rapidly than the parent, suggesting that cccA is expressed but cytochrome c 2 is not involved in electron transfer to cytochrome oxidase. The deletion of cccA increased the sensitivity of the cycB mutant to excess oxygen but decreased the sensitivity of the cycA mutant. Despite many attempts, a double mutant defective in both cytochromes c 4 and c 5 could not be isolated. However, a strain with the ectopically encoded, IPTG-inducible cycB gene with deletions in both cycA and cycB was constructed: the growth and survival of this strain were dependent upon the addition of IPTG, so gonococcal survival is dependent upon the synthesis of either cytochrome c 4 or c 5. These results define the gonococcal electron transfer chain to oxygen in which cytochromes c 4 and c 5, but not cytochrome c 2, provide alternative pathways for electron transfer from the cytochrome bc 1 complex to the terminal oxidase cytochrome cbb 3.

scholarly journals MicroRNA-205-5p inhibits skin cancer cell proliferation and increase drug sensitivity by targeting TNFAIP8

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xinhong Ge ◽  
Suryakant Niture ◽  
Minghui Lin ◽  
Patrice Cagle ◽  
P. Andy Li ◽  
...  
Keyword(s):  
Skin Cancer ◽  
Cell Carcinoma ◽  
Kinase Inhibitor ◽  
Ectopic Expression ◽  
Cancer Cell Proliferation ◽  
Growth And Survival ◽  
Cellular Autophagy ◽  
Increased Sensitivity ◽  
Factor Α

AbstractTumor necrosis factor-α-induced protein 8 (TNFAIP8) is a member of the TIPE/TNFAIP8 family which regulates tumor growth and survival. Our goal is to delineate the detailed oncogenic role of TNFAIP8 in skin cancer development and progression. Here we demonstrated that higher expression of TNFAIP8 is associated with basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma development in patient tissues. Induction of TNFAIP8 expression by TNFα or by ectopic expression of TNFAIP8 in SCC or melanoma cell lines resulted in increased cell growth/proliferation. Conversely, silencing of TNFAIP8 decreased cell survival/cell migration in skin cancer cells. We also showed that miR-205-5p targets the 3′UTR of TNFAIP8 and inhibits TNFAIP8 expression. Moreover, miR-205-5p downregulates TNFAIP8 mediated cellular autophagy, increased sensitivity towards the B-RAFV600E mutant kinase inhibitor vemurafenib, and induced cell apoptosis in melanoma cells. Collectively our data indicate that miR-205-5p acts as a tumor suppressor in skin cancer by targeting TNFAIP8.

Soil and plant resistances to water absorption by plant root systems

1979 ◽  
Vol 30 (2) ◽  
pp. 279 ◽  
Author(s):  
GJ Burch
Keyword(s):  
Water Absorption ◽  
Root System ◽  
Soil Water ◽  
Water Movement ◽  
Plant Root ◽  
Unit Length ◽  
Water Flux ◽  
Soil Water Potential ◽  
Root Systems ◽  
Soil Resistance

A study of water absorption by root systems of two herbage species, white clover (Trifolium repens L.) and tall fescue (Festuca arundinacea Schreb.), was used to partition the resistances to water flux between the soil and plant. A large and almost constant plant resistance influenced the pattern of water absorption until the soil resistance reached about 1.5 x 103 MPa s cm-3. This corresponded to an extraction of almost 80% of the available soil water. Water absorption from progressively deeper soil layers showed no evidence of any substantial resistance to water flux through the root xylem. Therefore, in wet soils, water movement into and through a root system is predominantly influenced by a large resistance to the radial water flux through root tissues outside the xylem. The radial resistance values for unit (cm) length of root were 6.49 x 106 and 6.54 x 106 MPa s cm-2 for clover and fescue respectively. A model of water uptake has been described which introduces two modified parameters for integrating the soil water potential (ψ) and the soil-root conductance (κ), over an entire root system. This study, along with other evidence from the literature, would indicate that for unit length of root the radial resistance to water absorption is reasonably similar, not only for an entire root system but also for a number of different species. An underestimation of the radial soil resistance (Rsr) to water absorption suggests that a root contact resistance (Rc) exists which could be due to the shrinkage of the soil or root, or both, with drying of the soil. This effect caused an increase in resistance to water absorption of about 48 x Rsr for fescue and 71 x Rsr for clover. This difference in Rc between the two species was attributed to a contrast in root morphology, especially a difference in the average root diameters of the two species.

THE EFFECT OF SODIUM DIMETHYLDITHIOCARBAMATE ON WATER UPTAKE, TRANSPIRATION, AND STOMATAL OPENING

1964 ◽  
Vol 42 (10) ◽  
pp. 1405-1410 ◽  
Author(s):  
G. D. Thorn ◽  
W. H. Minshall
Keyword(s):  
Amino Acids ◽  
Root System ◽  
Water Uptake ◽  
Water Movement ◽  
Stomatal Opening ◽  
Large Reduction ◽  
Root Pressure ◽  
Bean Plants ◽  
Detached Leaves ◽  
Total Amino Acids

Sodium dimethyldithiocarbamate, applied to the roots of tomato and bean plants, markedly decreases the rate of transpiration and prevents stomatal opening. The chemical also causes a large reduction in water movement associated with metabolic root pressure. The concentration of total amino acids moving out of the root system is reduced by as much as 50% of normal. Transpiration and stomatal opening of detached leaves from untreated plants are not affected appreciably by solutions of sodium dimethyldithiocarbamate.

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