Auxin stimulates lateral root formation of container-grown interior Douglas-fir seedlings

1986 ◽  
Vol 16 (5) ◽  
pp. 1135-1139 ◽  
Author(s):  
David G. Simpson
Keyword(s):  
Lateral Root ◽  
Root Formation ◽  
Lateral Roots ◽  
Dry Weight ◽  
Douglas Fir ◽  
Lateral Root Formation ◽  
Indolebutyric Acid ◽  
Shoot Height ◽  
First Order ◽  
Napthaleneacetic Acid

The effects of 1-napthaleneacetic acid (NAA) and 3-indolebutyric acid (IBA) soil drenches on lateral root formation and growth of interior Douglas-fir (Pseudotsugamenziesii var. glauca (Beissn.) Franco) seedlings were studied. At rates between 10−3 and 10−5 M, NAA was more effective than IBA in stimulating first-order lateral root formation. Seedling age influenced the degree of NAA-induced lateral root formation. At three different nurseries the greatest number of lateral roots was produced by seedlings receiving 10−4 M (18.62 mgL−1) NAA 30 days after sowing. Shoot height and dry weight were reduced, although not at the expense of root growth in some cases.

Lateral root formation and nutrients: nitrogen in the spotlight

2021 ◽  
Author(s):  
Pierre-Mathieu Pélissier ◽  
Hans Motte ◽  
Tom Beeckman
Keyword(s):  
Signaling Pathways ◽  
Root System ◽  
Root Development ◽  
Lateral Root ◽  
Molecular Mechanisms ◽  
Root Formation ◽  
Lateral Roots ◽  
Nutrient Use Efficiency ◽  
Lateral Root Formation ◽  
Lateral Root Development

Abstract Lateral roots are important to forage for nutrients due to their ability to increase the uptake area of a root system. Hence, it comes as no surprise that lateral root formation is affected by nutrients or nutrient starvation, and as such contributes to the root system plasticity. Understanding the molecular mechanisms regulating root adaptation dynamics towards nutrient availability is useful to optimize plant nutrient use efficiency. There is at present a profound, though still evolving, knowledge on lateral root pathways. Here, we aimed to review the intersection with nutrient signaling pathways to give an update on the regulation of lateral root development by nutrients, with a particular focus on nitrogen. Remarkably, it is for most nutrients not clear how lateral root formation is controlled. Only for nitrogen, one of the most dominant nutrients in the control of lateral root formation, the crosstalk with multiple key signals determining lateral root development is clearly shown. In this update, we first present a general overview of the current knowledge of how nutrients affect lateral root formation, followed by a deeper discussion on how nitrogen signaling pathways act on different lateral root-mediating mechanisms for which multiple recent studies yield insights.

scholarly journals The Rhizobium leguminosarum biovar trifolii ANU794 Induces Novel Developmental Responses on the Subterranean Clover Cultivar Woogenellup

2006 ◽  
Vol 19 (5) ◽  
pp. 471-479 ◽  
Author(s):  
Angela Carmen Morris ◽  
Michael Anthony Djordjevic
Keyword(s):  
Lateral Root ◽  
Rhizobium Leguminosarum ◽  
Root Formation ◽  
Fluorescent Protein ◽  
Lateral Roots ◽  
Hybrid Structures ◽  
Nodule Development ◽  
Lateral Root Formation ◽  
Low Efficiency ◽  
Developmental Responses

The clover-nodulating Rhizobium leguminosarum bv. trifolii ANU794 initiates normal root-nodule development with abnormally low efficiency on the Trifolium subterraneum cv. Woogenellup. The cellular and developmental responses of Woogenellup roots to the site- and dose-defined inoculation of green fluorescent protein (gfp)-labeled cells of ANU843 (nodulation proficient) and ANU794 was investigated using light, fluorescence, and confocal microscopy. Strain ANU794-gfp induced three primordia types and four developmental responses at the inoculation site: true or aberrant nodules (on 5 and 25% of plants, respectively), hybrid structures (20% of plants), or lateral roots (50% of plants). The novel hybrid structures possessed nodule and lateral root-like features and unusual vascular patterning. Strain ANU794-gfp induces lateral root formation by stimulating pericycle cell divisions at all nearby protoxylem poles. Only true nodules induced by ANU794-gfp contained intracellular bacteria. In contrast, strain ANU843-gfp induced nodules only and lateral root formation was suppressed at spot inoculation sites. Primordium types were distinguishable by the emission spectrum characteristics of phenolic UV-absorbing and fluorescent compounds that accumulate in primordium cells. Hybrid primordia contained (at least) two fluorescent cell populations, suggesting that they are chimeric. The results suggest that ANU794 may produce both nodule- and lateral root-generating signals simultaneously.

Differences among Populas species in ability to form adventitious shoots and roots

1976 ◽  
Vol 6 (3) ◽  
pp. 253-261 ◽  
Author(s):  
George A. Schier ◽  
Robert B. Campbell
Keyword(s):  
Lateral Root ◽  
Root Formation ◽  
Lateral Roots ◽  
Adventitious Shoots ◽  
Root Segment ◽  
Lateral Root Formation ◽  
Root Segments ◽  
Rooting Capacity

Differences in suckering from root segments and in rooting from sucker cuttings were studied among four species of Populus, including three poplars, P. angustifolia James, P. deltoides Bartr., and P. balsamifera L., and an aspen, P. tremuloides Michx. Places where suckers originated on root segments were more variable in the poplars than in the aspen. Whereas suckers developed in the aspen only from the periderm, suckers developed in the poplars from the periderm and from cambium exposed at the cut ends of segments and lateral roots. Poplar suckers arising from the periderm originated from preexisting suppressed buds embedded in the periderm. Suckers developed in the aspen from preexisting primordia. Lateral root formation from preexisting and newly initiated meristems on root segments was common in the poplars but rare in the aspen. The presence of lateral roots increased sucker growth, and the development of suckers and lateral roots responded to the inherent polarity of the root segment. Sucker cuttings from the poplars were generally superior in rooting capacity to those from the aspen.

EFFECT OF METAL NANOPARTICLES ON THE GROWTH OF NGOC LINH GINSENG (PANAX VIETNAMENSIS) LATERAL ROOTS CULTURED IN VITRO

2017 ◽  
Vol 126 (1C) ◽  
Author(s):  
Duong Tan Nhut ◽  
Nguyen Thi Nhat Linh ◽  
Nguyen Hoang Loc ◽  
Hoang Thanh Tung ◽  
Vu Thi Hien ◽  
...  
Keyword(s):  
Root Growth ◽  
Metal Nanoparticles ◽  
Lateral Root ◽  
Root Formation ◽  
Lateral Roots ◽  
Metal Nanoparticle ◽  
Ginseng Root ◽  
Lateral Root Formation ◽  
Triterpenoid Saponins

<p><em>Panax vietnamensis</em> (Ngoc Linh ginseng) plays critical roles in pharmaceutical industry because triterpenoid saponins from its roots produce medicine for improving health and treating many diseases. Metal nanoparticles reveal completely new or improved properties based on specific characteristics such as size, distribution and morphology compare to metal ion or salt; and their potential for <em>in vitro </em>plant cultures. Present study investigated the effects of metal nanoparticles including nZnO (0.5-2.5 mg/l), nAg (1-3 mg/l), and nCu (1-3 mg/l) supplemented in free-hormone-MS medium to <em>in vitro Panax vietnamensis </em>lateral root growth. Our results showed that metal nanoparticles have the positive effect on the growth of<em> in vitro P. vietnamensis </em>lateral<em> </em>roots with nAg, nCu, and nZnO. At different concentrations, <em>in vitro P. vietnamensis </em>lateral root growth also has various effects on the growth of lateral roots. In supplemented metal nanoparticle treatments, nCu is the most optimum for <em>in vitro P. vietnamensis</em> lateral root growth; the highest increase was obtained at 1.5 mg/l nCu treatment (99.3% lateral root formation and all root growth indexes are the highest). Besides, 2.5 mg/l nAg is also significantly noticed in ginseng root growth. However, the negative impact on the growth of the <em>in vitro P. vietnamensis</em> lateral roots showed when culture medium contained the highest concentration; such as the root growing inhibition of nCu and nAg above 2.5 mg/l. Especially, this decrease was higher with the application of nZnO0.5-2.5 mg/l (decrease the lateral root number) and 2.5 mg/l (decrease percent of lateral root formation).</p>

Cellular and molecular events in a newly organizing lateral root meristem

1995 ◽  
Vol 350 (1331) ◽  
pp. 39-43 ◽  
Keyword(s):  
Lateral Root ◽  
Root Formation ◽  
Developmental Process ◽  
Lateral Roots ◽  
Root Apical Meristem ◽  
Cdna Libraries ◽  
Lateral Root Formation ◽  
Ribosomal Protein Genes ◽  
Efficient System

Spontaneous or auxin-induced lateral root formation in radish and Arabidopsis provides an efficient system in which to examine molecular and cellular events associated with the initiation of a new meristem. Subtracted cDNA libraries made at different times in lateral root initiation were used as a source of genes that are expressed differentially during this developmental process, and expression studies on a small gene family of ribosomal protein genes were conducted. From analysis of cell division patterns in pericycle cells the number of founder cells for lateral roots was established. By the use of in vitro growth assays lateral root formation was determined to be a two-stage process. First a primordium is formed, and subsequently a subset of primordial cells begins to function as the lateral root apical meristem. This mode of root development has implications for pattern formation in newly organizing organs.

scholarly journals Interplay of Auxin and Cytokinin in Lateral Root Development

2019 ◽  
Vol 20 (3) ◽  
pp. 486 ◽  
Author(s):  
Hongwei Jing ◽  
Lucia Strader
Keyword(s):  
Lateral Root ◽  
Root Formation ◽  
Plant Root ◽  
Lateral Roots ◽  
Root System Architecture ◽  
Regulatory Mechanisms ◽  
Lateral Root Formation ◽  
Lateral Root Development ◽  
The Past ◽  
Plant Root System

The spacing and distribution of lateral roots are critical determinants of plant root system architecture. In addition to providing anchorage, lateral roots explore the soil to acquire water and nutrients. Over the past several decades, we have deepened our understanding of the regulatory mechanisms governing lateral root formation and development. In this review, we summarize these recent advances and provide an overview of how auxin and cytokinin coordinate the regulation of lateral root formation and development.

scholarly journals EFFECT OF METAL NANOPARTICLES ON THE GROWTH OF NGOC LINH GINSENG (PANAX VIETNAMENSIS) LATERAL ROOTS CULTURED IN VITRO

2017 ◽  
Vol 126 (1C) ◽  
pp. 47
Author(s):  
Nguyễn Thị Nhật Linh ◽  
Hoàng Thanh Tùng ◽  
Vũ Thị Hiền ◽  
Vũ Quốc Luận ◽  
Nguyễn Phúc Huy ◽  
...  
Keyword(s):  
Root Growth ◽  
Metal Nanoparticles ◽  
Lateral Root ◽  
Root Formation ◽  
Lateral Roots ◽  
Metal Nanoparticle ◽  
Ginseng Root ◽  
Lateral Root Formation ◽  
Triterpenoid Saponins

<p><em>Panax vietnamensis</em> (Ngoc Linh ginseng) plays critical roles in pharmaceutical industry because triterpenoid saponins from its roots produce medicine for improving health and treating many diseases. Metal nanoparticles reveal completely new or improved properties based on specific characteristics such as size, distribution and morphology compare to metal ion or salt; and their potential for <em>in vitro </em>plant cultures. Present study investigated the effects of metal nanoparticles including nZnO (0.5-2.5 mg/l), nAg (1-3 mg/l), and nCu (1-3 mg/l) supplemented in free-hormone-MS medium to <em>in vitro Panax vietnamensis </em>lateral root growth. Our results showed that metal nanoparticles have the positive effect on the growth of<em> in vitro P. vietnamensis </em>lateral<em> </em>roots with nAg, nCu, and nZnO. At different concentrations, <em>in vitro P. vietnamensis </em>lateral root growth also has various effects on the growth of lateral roots. In supplemented metal nanoparticle treatments, nCu is the most optimum for <em>in vitro P. vietnamensis</em> lateral root growth; the highest increase was obtained at 1.5 mg/l nCu treatment (99.3% lateral root formation and all root growth indexes are the highest). Besides, 2.5 mg/l nAg is also significantly noticed in ginseng root growth. However, the negative impact on the growth of the <em>in vitro P. vietnamensis</em> lateral roots showed when culture medium contained the highest concentration; such as the root growing inhibition of nCu and nAg above 2.5 mg/l. Especially, this decrease was higher with the application of nZnO0.5-2.5 mg/l (decrease the lateral root number) and 2.5 mg/l (decrease percent of lateral root formation).</p>

scholarly journals The expa1-1 mutant reveals a new biophysical lateral root organogenesis checkpoint

2018 ◽  
Author(s):  
Priya Ramakrishna ◽  
Graham A Rance ◽  
Lam Dai Vu ◽  
Evan Murphy ◽  
Kamal Swarup ◽  
...  
Keyword(s):  
Cell Division ◽  
Root System ◽  
Lateral Root ◽  
Root Formation ◽  
Lateral Roots ◽  
Lateral Root Formation ◽  
Asymmetric Cell Divisions ◽  
Cell Divisions ◽  
Root Organogenesis ◽  
Pericycle Cells

ABSTRACTIn plants, post-embryonic formation of new organs helps shape the adult organism. This requires the tight regulation of when and where a new organ is formed, and a coordination of the underlying cell divisions. To build a root system, new lateral roots are continuously developing, and this process requires asymmetric cell division in adjacent pericycle cells. Characterization of an expansin a1 (expa1) mutant has revealed a novel checkpoint during lateral root formation. Specifically, a minimal pericycle width was found to be necessary and sufficient to trigger asymmetric pericycle cell divisions during auxin-driven lateral root formation. We conclude that a localized radial expansion of adjacent pericycle cells is required to position the asymmetric cell divisions and generate a core of small daughter cells, which is a prerequisite for lateral root organogenesis.SIGNFICANCE STATEMENTOrgan formation is an essential process in plants and animals, driven by cell division and cell identity establishment. Root branching, where lateral roots form along the primary root axis, increases the root system and aids capture of water and nutrients. We have discovered that tight control of cell width is necessary to co-ordinate asymmetric cell divisions in cells that give rise to a new lateral root organ. While biomechanical processes have been shown to play a role in plant organogenesis, including lateral root formation, our data give new mechanistic insights into the cell size checkpoint during lateral root initiation.

scholarly journals Dynamic cytokinin signalling landscapes during lateral root formation in Arabidopsis

2021 ◽  
Vol 2 ◽  
Author(s):  
Milica Nenadić ◽  
Joop E. M. Vermeer
Keyword(s):  
Lateral Root ◽  
Root Formation ◽  
Developmental Process ◽  
Lateral Roots ◽  
Negative Regulator ◽  
Lateral Root Formation ◽  
Lateral Root Initiation ◽  
Open Questions ◽  
Root Organogenesis ◽  
Cell Layers

Abstract By forming lateral roots, plants expand their root systems to improve anchorage and absorb more water and nutrients from the soil. Each phase of this developmental process in Arabidopsis is tightly regulated by dynamic and continuous signalling of the phytohormones cytokinin and auxin. While the roles of auxin in lateral root organogenesis and spatial accommodation by overlying cell layers have been well studied, insights on the importance of cytokinin is still somewhat limited. Cytokinin is a negative regulator of lateral root formation with versatile modes of action being activated at different root developmental zones. Here, we review the latest progress made towards our understanding of these spatially separated mechanisms of cytokinin-mediated signalling that shape lateral root initiation, outgrowth and emergence and highlight some of the enticing open questions.

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