Understanding the root sink.

2022 ◽  
pp. 59-66
Author(s):  
T. M. DeJong
Keyword(s):  
Root Growth ◽  
Root Development ◽  
Apical Meristem ◽  
Shoot Growth ◽  
Lateral Roots ◽  
Fruit Trees ◽  
Extension Growth ◽  
Factors Affecting ◽  
And Function ◽  
Shoot Meristems

Abstract Root development and growth is similar to shoot growth in that extension growth is initiated by an apical meristem and girth growth of mature roots is carried out by the vascular cambium. However, the initiation of lateral roots is entirely different than the initiation of lateral leaves or shoot meristems. This chapter deals with understanding the root sink in fruit trees by studying root growth, including the initiation of lateral roots, root classification according to size and function, factors affecting their growth, and rootstocks.

scholarly journals Root and Shoot Growth Periodicity of Green Ash, Scarlet Oak, Turkish Hazelnut, and Tree Lilac

1995 ◽  
Vol 120 (2) ◽  
pp. 211-216 ◽  
Author(s):  
J. Roger Harris ◽  
Nina L. Bassuk ◽  
Richard W. Zobel ◽  
Thomas H. Whitlow
Keyword(s):  
Root Growth ◽  
Root Length ◽  
Shoot Growth ◽  
Lateral Roots ◽  
Growth Patterns ◽  
Extension Rate ◽  
Green Ash ◽  
Growth Measurement ◽  
Root And Shoot Growth ◽  
Growth Periodicity

The objectives of this study were to determine root and shoot growth periodicity for established Fraxinus pennsylvanica Marsh. (green ash), Quercus coccinea Muenchh. (scarlet oak), Corylus colurna L. (Turkish hazelnut), and Syringa reticulata (Blume) Hara `Ivory Silk' (tree lilac) trees and to evaluate three methods of root growth periodicity measurement. Two methods were evaluated using a rhizotron. One method measured the extension rate (RE) ofindividual roots, and the second method measured change in root length (RL) against an observation grid. A third method, using periodic counts of new roots present on minirhizotrons (MR), was also evaluated. RE showed the least variability among individual trees. Shoot growth began before or simultaneously with the beginning of root growth for all species with all root growth measurement methods. All species had concurrent shoot and root growth, and no distinct alternating growth patterns were evident when root growth was measured by RE. Alternating root and shoot growth was evident, however, when root growth was measured by RL and MR. RE measured extension rate of larger diameter lateral roots, RL measured increase in root length of all diameter lateral roots and MR measured new root count of all sizes of lateral and vertical roots. Root growth periodicity patterns differed with the measurement method and the types of roots measured.

Characterisation of three shoot apical meristem mutants of Arabidopsis thaliana

Development ◽  
1992 ◽  
Vol 116 (2) ◽  
pp. 397-403 ◽  
Author(s):  
H. M. Ottoline Leyser ◽  
I. J. Furner
Keyword(s):  
Arabidopsis Thaliana ◽  
Root Growth ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Floral Development ◽  
Wild Type ◽  
Recessive Mutations ◽  
Phenotypic Characterisation ◽  
Dicotyledonous Plants ◽  
And Function

The shoot apical meristem of dicotyledonous plants is highly regulated both structurally and functionally, but little is known about the mechanisms involved in this regulation. Here we describe the genetic and phenotypic characterisation of recessive mutations at three loci of Arabidopsis thaliana in which meristem structure and function are disrupted. The loci are Clavata1 (Clv1), Fasciata1 (Fas1) and Fasciata2 (Fas2). Plants mutant at these loci are fasciated having broad, flat stems and disrupted phyllotaxy. In all cases, the fasciations are associated with shoot apical meristem enlargement and altered floral development. While all the mutants share some phenotypic features they can be divided into two classes. The pleiotropic fas1 and fas2 mutants are unable to initiate wild- type organs, show major alterations in meristem structure and have reduced root growth. In contrast, clv1 mutant plants show near wild-type organ phenotypes, more subtle changes in shoot apical meristem structure and wild-type root growth.

Effects of controlled-release fertilizers on shoot and root development of outplanted western hemlock (Tsugaheterophylla Raf. Sarg.) seedlings

1981 ◽  
Vol 11 (4) ◽  
pp. 752-757 ◽  
Author(s):  
William C. Carlson
Keyword(s):  
Controlled Release ◽  
Root Growth ◽  
Root Development ◽  
Root Zone ◽  
Lateral Roots ◽  
Total Weight ◽  
Western Hemlock ◽  
Seedling Size ◽  
Growing Seasons ◽  
Controlled Release Fertilizers

Controlled-release fertilizers applied to the root zone of 1-0 plug western hemlock (Tsugaheterophylla Raf. Sarg.) at planting stimulated shoot and root growth in the following two growing seasons. The number and diameter of lateral roots was increased by fertilizing, but fertilizing did not alter the shoot–root ratio. The shoot–root ratio did not increase with an increase in seedling size, height, or total weight.

scholarly journals The quiescent centre and root apical meristem: organization and function

2021 ◽  
Author(s):  
Joseph G Dubrovsky ◽  
Kris Vissenberg
Keyword(s):  
Root Growth ◽  
Apical Meristem ◽  
100Th Anniversary ◽  
Root Apical Meristem ◽  
Quiescent Centre ◽  
Special Issue ◽  
Future Directions ◽  
Cell Production ◽  
And Function

Abstract This special issue is dedicated to the 100th anniversary of the birth of Frederick Albert Lionel Clowes, who discovered the quiescent centre (QC) of the root apical meristem (RAM). His discovery was a foundation for contemporary studies of the QC and RAM function, maintenance, and organization. RAM function is fundamental for cell production and root growth. This special issue bundles reviews on the main tendencies, hypotheses, and future directions, and identifies unknowns in the field.

scholarly journals Conserved LBL1-ta-siRNA and miR165/166-RLD1/2 modules regulate root development in maize

Development ◽  
2020 ◽  
Vol 148 (1) ◽  
pp. dev190033
Author(s):  
Vibhav Gautam ◽  
Archita Singh ◽  
Sandeep Yadav ◽  
Sharmila Singh ◽  
Pramod Kumar ◽  
...  
Keyword(s):  
Root Growth ◽  
Root Development ◽  
Lateral Roots ◽  
Root System Architecture ◽  
Maize Root ◽  
Altered Expression ◽  
Auxin Distribution ◽  
Seminal Roots ◽  
Crown Roots

ABSTRACTRoot system architecture and anatomy of monocotyledonous maize is significantly different from dicotyledonous model Arabidopsis. The molecular role of non-coding RNA (ncRNA) is poorly understood in maize root development. Here, we address the role of LEAFBLADELESS1 (LBL1), a component of maize trans-acting short-interfering RNA (ta-siRNA), in maize root development. We report that root growth, anatomical patterning, and the number of lateral roots (LRs), monocot-specific crown roots (CRs) and seminal roots (SRs) are significantly affected in lbl1-rgd1 mutant, which is defective in production of ta-siRNA, including tasiR-ARF that targets AUXIN RESPONSE FACTOR3 (ARF3) in maize. Altered accumulation and distribution of auxin, due to differential expression of auxin biosynthesis and transporter genes, created an imbalance in auxin signalling. Altered expression of microRNA165/166 (miR165/166) and its targets, ROLLED1 and ROLLED2 (RLD1/2), contributed to the changes in lbl1-rgd1 root growth and vascular patterning, as was evident by the altered root phenotype of Rld1-O semi-dominant mutant. Thus, LBL1/ta-siRNA module regulates root development, possibly by affecting auxin distribution and signalling, in crosstalk with miR165/166-RLD1/2 module. We further show that ZmLBL1 and its Arabidopsis homologue AtSGS3 proteins are functionally conserved.

scholarly journals Tree Root Growth and Development. I. Form, Spread, Depth and Periodicity

1990 ◽  
Vol 8 (4) ◽  
pp. 215-220 ◽  
Author(s):  
Edward F. Gilman
Keyword(s):  
Moisture Content ◽  
Root Growth ◽  
Fine Roots ◽  
Growth And Development ◽  
Shoot Growth ◽  
Lateral Roots ◽  
Soil Characteristics ◽  
Soil Conditions ◽  
Urban Landscapes ◽  
Root Growth And Development

Abstract Root form is governed by seedling genetics and soil characteristics including texture, compaction, depth to the water table, fertility, moisture content and other factors. Trees develop lateral roots growing parallel to the surface of the soil. These are generally located in the top 30 cm (12 in) of soil. Fine roots emerge from lateral roots and grow into the soil close to the surface. If soil conditions permit, some trees grow tap and other vertically oriented roots capable of penetrating several feet into the soil. Many trees, particularly those planted in urban landscapes, do not generate tap roots. Lateral roots spread to well beyond the edge of the branches. Their growth in governed by competition from other plants, available water, soil temperature, fertility, stage of shoot growth and other factors.

scholarly journals Response of 13 Species of Landscape Plants to Altered Photoperiods

1987 ◽  
Vol 5 (4) ◽  
pp. 152-154
Author(s):  
Gary J. Keever ◽  
Gary S. Cobb
Keyword(s):  
Root Growth ◽  
Root Development ◽  
Shoot Growth ◽  
Growth Patterns ◽  
Landscape Plants ◽  
Long Day ◽  
Winter Temperatures ◽  
Landscape Trees ◽  
Trees And Shrubs

Thirteen species of temperate landscape trees and shrubs grown outdoors in Mobile, Alabama from March 26, 1985, until June 5, 1986, were exposed to natural (NP), night interrupted (NI), or extended (EP) photopenods from June 21 until November 15. Shoot growth measured in December varied among species but was either greater under long day conditions or similar to growth under NP, whereas root development was greater with NP or unaffected by photoperiod. By June 1986 shoot growth was either greater under NP or similar to growth under EP or NI. Root growth patterns were similar to those observed in December. Six species exposed to long day conditions exhibited extensive twig dieback, following subfreezing winter temperatures.

scholarly journals INFLUENCE OF CONTAINER SIZE AND TRANSPLANT SEQUENCE ON ROOT DEVELOPMENT OF TWO ILEX SPECIES

HortScience ◽  
1992 ◽  
Vol 27 (11) ◽  
pp. 1166a-1166
Author(s):  
Patricia R. Knight ◽  
D. Joseph Eakes ◽  
Kenneth M. Tilt ◽  
Charles H. Gilliam
Keyword(s):  
Root Growth ◽  
Root Development ◽  
Root Distribution ◽  
Shoot Growth ◽  
Dry Weight ◽  
Stem Cuttings ◽  
Root Dry Weight

Stem cuttings of Ilex cornuta `Burfordii Nana' and Ilex × `Nellie R. Stevens', were direct stuck into cell pack, rose pot, quart pot, and trade gallon containers on March 4, 1991. Ten weeks and again at twenty weeks after sticking, rooted liners from cell pack, rose pot, and quart pot containers were transplanted into trade gallon containers. Thirty weeks after sticking, Nellie R. Stevens holly had a greater total root dry weight compared to Dwarf Burford holly. There were no differences in total root dry weight for any transplant treatment, but root distribution was influenced. Cell pack and rose pot liners transplanted twenty weeks after sticking showed a reduction in root growth in the root sector between the radius of a quart pot and a trade gallon pot. Shoot growth was also reduced for cell pack and rose pot liners that were transplanted into trade gallon containers twenty weeks after sticking.

scholarly journals The influence of mechanical resistance and phosphate supply on morphology and function of maize roots.

1982 ◽  
Vol 30 (3) ◽  
pp. 179-192 ◽  
Author(s):  
F.R. Boone ◽  
B.W. Veen
Keyword(s):  
Root Growth ◽  
Shoot Growth ◽  
Sandy Loam ◽  
Specific Root Length ◽  
Mechanical Resistance ◽  
P Availability ◽  
Low Light ◽  
Maize Roots ◽  
And Function ◽  
Different Levels

In 3 pot experiments, maize cv. Avanti was grown on a marine sandy loam compacted to different pore vol. and supplied with different rates of P. Root wt. was not changed by different levels of mechanical resistance but root extension growth and cone resistance were curvilinearly related. At high mechanical resistance, root growth was more horizontal; vertical root growth was very limited at high cone resistances. Specific root length was also smaller, root diam. larger and fewer laterals/cm main root were developed although their av. length was not affected. The influence of mechanical resistance on root distribution and morphology reduced nutrient uptake and therefore shoot growth. With low P availability, P limited shoot growth more the higher the mechanical resistance. With sufficient P, K had the same effect. If an aboveground factor such as a low light intensity limited shoot growth, mechanical resistance had no effect on shoot growth. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Root mapping of three tropical pasture species using 32P

1969 ◽  
Vol 9 (39) ◽  
pp. 445 ◽  
Author(s):  
RA Bray ◽  
JB Hacker ◽  
DE Byth
Keyword(s):  
Root Growth ◽  
Root Development ◽  
Lateral Root ◽  
Sandy Loam ◽  
Lateral Roots ◽  
Root Systems ◽  
Growth Patterns ◽  
Constant Rate ◽  
Initial Root

Root growth patterns of Glycine javanica, Setaria anceps, and Medicago sativa were studied by uptake of 32P from a sandy loam. Placement of isotope was through permanently positioned PVC conduit on a grid over a 90� quadrant of the root system. Detection of radioactivity was in in situ plant material. Lucerne had strong initial root development but was slow to form lateral roots. Glycine and Setaria had quite similar root systems although Setaria had more rapid vertical root development than Glycine. Both these species had strong lateral root systems. When a regression of minimum root length against time was calculated, lateral root growth was shown to be independent of depth and distance from the plant, suggesting that roots behave as if growing from a point source in random directions at a constant rate. This rate was the same for all species. There were also indications of strong vertical root systems in lucerne and Setaria.

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