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Gene Networks Involved in Hormonal Control of Root Development in Arabidopsis thaliana: A Framework for Studying Its Disturbance by Metal Stress.

De Smet S, Cuypers A, Vangronsveld J, Remans T - Int J Mol Sci (2015)

Bottom Line: Furthermore, cytokinins, gibberellins, abscisic acid, ethylene, jasmonic acid, strigolactones, brassinosteroids and salicylic acid are discussed.Interactions between hormones that are of potential importance for root growth are described.This creates a framework that can be used for investigating the impact of abiotic stress factors on molecular mechanisms related to plant hormones, with the limited knowledge of the effects of the metals cadmium, copper and zinc on plant hormones and root development included as case example.

View Article: PubMed Central - PubMed

Affiliation: Centre for Environmental Sciences, Environmental Biology, Hasselt University, Agoralaan Gebouw D, 3590 Diepenbeek, Belgium. stefanie.desmet@uhasselt.be.

ABSTRACT
Plant survival under abiotic stress conditions requires morphological and physiological adaptations. Adverse soil conditions directly affect root development, although the underlying mechanisms remain largely to be discovered. Plant hormones regulate normal root growth and mediate root morphological responses to abiotic stress. Hormone synthesis, signal transduction, perception and cross-talk create a complex network in which metal stress can interfere, resulting in root growth alterations. We focus on Arabidopsis thaliana, for which gene networks in root development have been intensively studied, and supply essential terminology of anatomy and growth of roots. Knowledge of gene networks, mechanisms and interactions related to the role of plant hormones is reviewed. Most knowledge has been generated for auxin, the best-studied hormone with a pronounced primary role in root development. Furthermore, cytokinins, gibberellins, abscisic acid, ethylene, jasmonic acid, strigolactones, brassinosteroids and salicylic acid are discussed. Interactions between hormones that are of potential importance for root growth are described. This creates a framework that can be used for investigating the impact of abiotic stress factors on molecular mechanisms related to plant hormones, with the limited knowledge of the effects of the metals cadmium, copper and zinc on plant hormones and root development included as case example.

No MeSH data available.


Related in: MedlinePlus

Lateral root development. (I) Lateral root initiation—Anticlinal division of lateral root founder cells in the pericycle; (II) Outer and inner cell layers are formed by periclinal divisions; (III) Periclinal divisions of the outer layer makes dome shape of the LRP is apparent (three-layered); (IV) As a result of periclinal divisions the primordium becomes four-layered; (V) After anticlinal divisions, the primordium begins to push through the cortex of the primary root; (VI) Different cell types are being formed; (VII) Lateral root meristem is established and primordium enlarges; and (VIII) Primordium is about to emerge after which the lateral root meristem will be activated (Based on Malamy and Benfey, 1997 [7]).
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ijms-16-19195-f002: Lateral root development. (I) Lateral root initiation—Anticlinal division of lateral root founder cells in the pericycle; (II) Outer and inner cell layers are formed by periclinal divisions; (III) Periclinal divisions of the outer layer makes dome shape of the LRP is apparent (three-layered); (IV) As a result of periclinal divisions the primordium becomes four-layered; (V) After anticlinal divisions, the primordium begins to push through the cortex of the primary root; (VI) Different cell types are being formed; (VII) Lateral root meristem is established and primordium enlarges; and (VIII) Primordium is about to emerge after which the lateral root meristem will be activated (Based on Malamy and Benfey, 1997 [7]).

Mentions: Lateral roots originate from mature pericycle cells positioned at either one of the xylem poles, but never at the phloem pool. Not all pericycle cells can form lateral roots, only those that have been primed before in the basal meristem. Primed cells are called lateral root founder cells and can become activated once a minimal threshold distance between the founder cell and the root tip is reached. Lateral root initiation (LRI), defined as the first division of the founder cells, occurs in the DZ [5,6]. A series of orchestrated periclinal and anticlinal cell divisions forms a lateral root primordium (LRP) in eight stages, described by Malamy and Benfey [7] (Figure 2). The emergence of the primordium through the parent root epidermis occurs mostly through cell expansion and involves cell wall remodelling enzymes that facilitate the separation of parental root cells. The LRP themselves are not affected by the enzymes because of differences in cell wall composition: the pectins in the primordia are largely methylated, while those of the parental cell wall are demethylated. Once the lateral root has emerged, its meristem is activated, and further growth results in a similar radial and an apical-basal polarity as described above [2,8].


Gene Networks Involved in Hormonal Control of Root Development in Arabidopsis thaliana: A Framework for Studying Its Disturbance by Metal Stress.

De Smet S, Cuypers A, Vangronsveld J, Remans T - Int J Mol Sci (2015)

Lateral root development. (I) Lateral root initiation—Anticlinal division of lateral root founder cells in the pericycle; (II) Outer and inner cell layers are formed by periclinal divisions; (III) Periclinal divisions of the outer layer makes dome shape of the LRP is apparent (three-layered); (IV) As a result of periclinal divisions the primordium becomes four-layered; (V) After anticlinal divisions, the primordium begins to push through the cortex of the primary root; (VI) Different cell types are being formed; (VII) Lateral root meristem is established and primordium enlarges; and (VIII) Primordium is about to emerge after which the lateral root meristem will be activated (Based on Malamy and Benfey, 1997 [7]).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4581294&req=5

ijms-16-19195-f002: Lateral root development. (I) Lateral root initiation—Anticlinal division of lateral root founder cells in the pericycle; (II) Outer and inner cell layers are formed by periclinal divisions; (III) Periclinal divisions of the outer layer makes dome shape of the LRP is apparent (three-layered); (IV) As a result of periclinal divisions the primordium becomes four-layered; (V) After anticlinal divisions, the primordium begins to push through the cortex of the primary root; (VI) Different cell types are being formed; (VII) Lateral root meristem is established and primordium enlarges; and (VIII) Primordium is about to emerge after which the lateral root meristem will be activated (Based on Malamy and Benfey, 1997 [7]).
Mentions: Lateral roots originate from mature pericycle cells positioned at either one of the xylem poles, but never at the phloem pool. Not all pericycle cells can form lateral roots, only those that have been primed before in the basal meristem. Primed cells are called lateral root founder cells and can become activated once a minimal threshold distance between the founder cell and the root tip is reached. Lateral root initiation (LRI), defined as the first division of the founder cells, occurs in the DZ [5,6]. A series of orchestrated periclinal and anticlinal cell divisions forms a lateral root primordium (LRP) in eight stages, described by Malamy and Benfey [7] (Figure 2). The emergence of the primordium through the parent root epidermis occurs mostly through cell expansion and involves cell wall remodelling enzymes that facilitate the separation of parental root cells. The LRP themselves are not affected by the enzymes because of differences in cell wall composition: the pectins in the primordia are largely methylated, while those of the parental cell wall are demethylated. Once the lateral root has emerged, its meristem is activated, and further growth results in a similar radial and an apical-basal polarity as described above [2,8].

Bottom Line: Furthermore, cytokinins, gibberellins, abscisic acid, ethylene, jasmonic acid, strigolactones, brassinosteroids and salicylic acid are discussed.Interactions between hormones that are of potential importance for root growth are described.This creates a framework that can be used for investigating the impact of abiotic stress factors on molecular mechanisms related to plant hormones, with the limited knowledge of the effects of the metals cadmium, copper and zinc on plant hormones and root development included as case example.

View Article: PubMed Central - PubMed

Affiliation: Centre for Environmental Sciences, Environmental Biology, Hasselt University, Agoralaan Gebouw D, 3590 Diepenbeek, Belgium. stefanie.desmet@uhasselt.be.

ABSTRACT
Plant survival under abiotic stress conditions requires morphological and physiological adaptations. Adverse soil conditions directly affect root development, although the underlying mechanisms remain largely to be discovered. Plant hormones regulate normal root growth and mediate root morphological responses to abiotic stress. Hormone synthesis, signal transduction, perception and cross-talk create a complex network in which metal stress can interfere, resulting in root growth alterations. We focus on Arabidopsis thaliana, for which gene networks in root development have been intensively studied, and supply essential terminology of anatomy and growth of roots. Knowledge of gene networks, mechanisms and interactions related to the role of plant hormones is reviewed. Most knowledge has been generated for auxin, the best-studied hormone with a pronounced primary role in root development. Furthermore, cytokinins, gibberellins, abscisic acid, ethylene, jasmonic acid, strigolactones, brassinosteroids and salicylic acid are discussed. Interactions between hormones that are of potential importance for root growth are described. This creates a framework that can be used for investigating the impact of abiotic stress factors on molecular mechanisms related to plant hormones, with the limited knowledge of the effects of the metals cadmium, copper and zinc on plant hormones and root development included as case example.

No MeSH data available.


Related in: MedlinePlus