Spelling suggestions: "subject:"roots (botany)devevelopment."" "subject:"roots (botany)agentdevelopment.""
1 |
Molecular and genetic studies into the formation of lateral roots in Eucalyptus and ArabidopsisPelosi, Assunta, 1969- January 2002 (has links)
Abstract not available
|
2 |
Identification, isolation, expression analysis and molecular characterization of nine genes key to late embryogenesis in Loblolly pineJones, Brande 22 January 2011 (has links)
A basic understanding of the molecular events occurring during zygotic embryogenesis is required to fully understand how and why only a very small percentage of somatic embryos develop past the late embryogeny phase of embryogenesis. In this work, we have identified genes that have been demonstrated to be required for late embryonic development in the model plant system Arabidopsis thaliana.
These genes were subsequently isolated and cloned from Loblolly pine embryos. These isolated clones were sequenced and analyzed to reveal significant homology to the known Arabidopsis ABA responsive genes ABI3, ABI4, and ABI5. Expression analyses of all three genes were completed, and compared to reported data of ABA accumulation, as well as, expression of other ABA responsive genes during the same stages of embryogenesis.
Six putative root development genes were isolated and cloned from Loblolly pine embryos. These isolated clones were sequenced and analyzed to reveal significant homology to the known Arabidopsis root development genes WOODENLEG, SHORT ROOT, SCARECROW, HOBBIT, BODENLOS, and MONOPTEROS. Full-length cDNAs were isolated and cloned for WOODENLEG, SHORT ROOT, SCARECROW and BODENLOS. Expression analyses of all six genes were completed throughout mid to late embryogenesis in Loblolly pine.
|
3 |
The development of a wall-less plug for planting stock of forest trees.Schuermans, Jean. 14 November 2013 (has links)
High output commercial nurseries that cater for the forestry industry are continuously
challenged to efficiently and cost effectively produce good quality planting stock to establish
large plantations. Currently, South African commercial nurseries produce planting stock in
solid compartmentalized trays. One of the major drawbacks of these containers is the
susceptibility of trees to root deformation following outplanting, combined with the need for
the return of empty containers to the nursery. A potential solution to these challenges is the
introduction of wall-less plugs for the production of planting stock. Wall-less plugs are
volumes of growing medium, usually cylindrical in shape, devoid of an impenetrable wall in
which a plant can grow and establish itself. Such plugs may enable the production of planting
stock with improved root systems, without the need for the return of empty containers after
outplanting. In this research four prototypes of wall-less plugs were developed, produced on a
small scale and tested. These were: 1) Paper-maché plugs made using the original WRIBLOK
protocol whereby composted pine bark was bound together with repulped newspaper, 2)
Sponge blocks, 3) Hessian bags and 4) Covetan bags. The performance of these prototype
wall-less plugs was compared with the performance of four tray types used commercially by
the forestry industry: 1) Poly 128 shallow, 2) Poly 98 deep, 3) Unigro 128 and 4) Sappi 49.
These are polystyrene and polypropylene-based containers. Of these containers the Unigro
128 and Sappi 49 containers were of similar performance. Performance in terms of height and
root collar diameter increase over ten weeks from the time of sowing of the paper-maché
plugs was similar to that of the Unigro and Sappi 49 containers. The sponge block, Hessian
bags and Covetan bags produced inferior quality planting stock compared to the other
treatments tested.
Although little progress was made in the ability to describe how one root system differs from
another in terms of their branching patterns, a technique was developed to determine root
surface area by image analysis software that is freely available. This method may prove useful
for further research and for determining seedling quality in commercial nurseries. / Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.
|
4 |
A Lateral Root Defect in the wag1-1/wag2-1 Double Mutant of ArabidopsisRowland, Steven D. 07 August 2012 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The root system architecture of higher plants plays an essential role in the uptake of water and nutrients as well as the production of hormones. These root systems are highly branched with the formation of post-embryonic organs such as lateral roots. The initiation and development of lateral roots has been well defined. WAG1 and WAG2 are protein-serine/threonine kinases from Arabidopsis that are closely related to PINOID and suppress root waving. The wag1;wag2 double mutants exhibit a strong root waving phenotype on vertical hard agar plates only seen in wild-type roots when the seedlings are grown on inclined plates. Here an additional root phenotype in the wag1;wag2 mutant is reported. The wag1;wag2 double mutant displays both an increased total number and density of emerged lateral roots (approximately 1.5-fold). An increased LRP density of 1.5-fold over wild-type is observed. To ascertain the role of WAG1 and WAG2 in lateral root development we examined promoter activity in the WAG1::GUS and WAG2::GUS lines. The WAG1 promoter showed no detectable activity at any stage of development. The WAG2 promoter was active in stage IV onward,
however there was no detectable activity in the cell types associated with initiation events. The lateral root density and spatial patterning in wild-type, when grown on inclined hard agar plates, was similar to wag1;wag2 on vertical plates. Seedlings of both genotypes were treated with hormones such as auxin and MeJA, and inhibitors. Auxin response in wag1;wag2 was normal with a similar number of LR as the wild-type after treatment. Treatment with MeJA resulted in a similar induction of LRP in both genotypes, however the percent lateral root emergence in wag1;wag2 was reduced while Col-0 was increased compared to controls. Treatment with the calcium blocker tetracaine resulted in wag1;wag2 displaying a wild-type level of LR but had no significant effect on wild-type. Genetic analysis of the wag1;wag2 LR pathway revealed that WAG1 and WAG2 are acting in the same pathway as AUX1, AXR1and PGM1. pgm1-1 was not previously reported to have a LR defect but showed decreased LR formation here, while pgm1;wag1;wag2 had a similar LR density to wag1;wag2. TIR7 and ARG1 were both deduced to operate in separate pathways from WAG1 and WAG2. The data presented here shows that the wag1;wag2 double mutant has an increased number of LR compared to Col-0. This defect appears to be caused by increased pre-initiation events and seems to be tied to the root waving phenotype. However, the treatment with MeJA revealed a possible role for WAG1 or WAG2 in LRP development, potentially under stress conditions. Calcium also seems to play a significant role in the wag1;wag2 LR phenotype, possibly independent of the root waving phenotype.
|
5 |
An investigation into the use of ROL genes to alter root formation and growth in transgenic plantsChow, Elaine Kiaw Fui, 1972- January 2001 (has links)
Abstract not available
|
Page generated in 0.0913 seconds