Cyclin B1;1 activity is observed in lateral roots but not in the primary root during lethal salinity and salt stress recovery

The AT-HOOK MOTIF NUCLEAR LOCALIZED PROTEIN (AHL) gene family encodes embryophyte-specific nuclear proteins with DNA binding activity. They modulate gene expression and affect various developmental processes in plants. We identify AHL18 (At3G60870) as a developmental modulator of root system architecture and growth. AHL18 regulates the length of the proliferation domain and number of dividing cells in the root apical meristem and thereby, cell production. Both primary root growth and lateral root development respond according to AHL18 transcription level. The ahl18 knock-out plants show reduced root systems due to a shorter primary root and a lower number of lateral roots. This change results from a higher number of arrested and non-developing lateral root primordia (LRP) rather than from decreased initiation. Overexpression of AHL18 results in a more extensive root system, longer primary roots, and increased density of lateral root initiation events. Formation of lateral roots is affected during the initiation of LRP and later development. AHL18 regulate root apical meristem activity, lateral root initiation and emergence, which is in accord with localization of its expression.

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Bare Root Liner Production Can Alter Tree Root Architecture

Journal of Environmental Horticulture ◽

10.24266/0738-2898-27.2.99 ◽

2009 ◽

Vol 27 (2) ◽

pp. 99-104 ◽

Cited By ~ 3

Author(s):

Angela Hewitt ◽

Gary Watson

Keyword(s):

Acer Saccharum ◽

Root Architecture ◽

Lateral Roots ◽

Primary Root ◽

Root Pruning ◽

Rooted Cuttings ◽

Nursery Production ◽

Structural Roots ◽

Production Practices ◽

Bare Root

Abstract Typical nursery production practices, such as root pruning and transplanting, can alter tree root architecture and contribute to root systems that are too deep. In a study of field-grown liner production, root architecture was examined at each stage of the production process, from first year seedlings or rooted cuttings, through 4 to 5 year old branched liners. Depth and diameter of structural roots were recorded on ten replications each of Acer saccharum, Gleditsia triancanthos, Pyrus calleryana, and apple seedling rootstocks; Platanus ‘Columbia’ clonal rooted cuttings; and apple EMLA 111 clonal rootstock produced by mound propagation. By the time the liners reached marketable size, most natural lateral roots emerging from the primary root were lost. Simultaneously, adventitious roots were produced deeper on the root shank at the pruned end of the primary root. These changes in architecture result in the formation of an ‘adventitious root flare’ that is deeper in the soil than a natural root flare. The depth of this new root flare is dependent upon nursery production practices and may influence the ultimate depth of structural roots in the landscape.

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DEVELOPMENTAL STUDIES ON EUPHORBIA ESULA L.: MORPHOLOGY OF THE ROOT SYSTEM

Canadian Journal of Botany ◽

10.1139/b63-049 ◽

1963 ◽

Vol 41 (5) ◽

pp. 579-589 ◽

Cited By ~ 20

Author(s):

M. V. S. Raju ◽

T. A. Steeves ◽

R. T. Coupland

Keyword(s):

Root System ◽

Lateral Roots ◽

Primary Root ◽

Cambial Activity ◽

Euphorbia Esula ◽

Developmental Studies ◽

Limited Growth ◽

Mode Of Reproduction ◽

Shoot Buds ◽

Adverse Conditions

The significance of Euphorbia esula L. as a weed is related to its capacity to persist under adverse conditions and to its mode of reproduction. In both these properties, the root system plays an important role. The root system is initially established by seedlings. The seedling has a vigorous primary root with extensive longitudinal growth and considerable cambial activity. Such a root has been designated a "long" root. By contrast, the first lateral roots produced on the primary root have limited growth and no cambial activity. These roots have been termed "short" roots. Thus, the seedling exhibits a "heterorhizic" pattern. Lateral long roots also arise on the primary root of seedlings but their origin is delayed until cambial activity has begun. Such lateral long roots arise much earlier on seedlings growing in denuded areas than on those growing in areas covered by dense vegetation. The mature root system is described in terms of horizontal and vertical long roots, which make up the conspicuous framework of the system, and of the short roots which they produce. Long roots produce shoot-buds and the origin of these structures is delayed until cambial activity has started. Short roots do not give rise to shoot-buds. Cambial activity in long roots appears to be connected with bud production and its absence in short roots probably underlies their inability to produce buds.L'importance de Euphorbia esula L. comme mauvaise herbe est connexé a son capacité de persister dans les situations hostiles et à sa methode de reproduction. Dans ces deux caractéristiques, le système des racines a une signification profunde. Initialement le système des racines s'établit dans le semis. Le semis a une racine primaire très forte avec beaucoup de croissance longitudinale et avec une activité considérable du cambium. Une racine de cette espèce s'appelle une "longue" racine (long root). Par contre, les premières racines latérales que poussent sur la racine primaire ont croissance limité et aucun activité du cambium. Ces racines s'appellent les "courtes" racines (short roots). De cette façon, le semis montre un dessin "heterorhizique" (heterorhizic). Les longues racines latérales ont aussi leur origine sur la racine primaire du semis, mais l'origine est retardé jusqu'au commencement de l'activité du cambium. Les racines de cette espèce apparaissent beaucoup plus tôt sur les semis qui sont situés en terre sans autre végétation, que sur ceux qui sont situés au milieu des autres plantes. Le système adulte des racines se décrit sous forme des longues racines de l'espèce horizontale et verticale, lesquelles constituent la charpente bien visible du système, et des courtes racines que sont produites par les longues racines. Les longues racines produisent les bourgeons, mais l'origine des bourgeons est retardé jusqu'au commencement de l'activité du cambium dans les racines. Les courtes racines ne produisent pas les bourgeons. Il paraît que l'activité du cambium dans les longues racines soit corrélative avec l'initiation des bourgeons et l'absence du cambium dans les courtes racines explique probablement leur incapacité à produire les bourgeons.

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LOP1: a gene involved in auxin transport and vascular patterning in Arabidopsis

Development ◽

10.1242/dev.122.6.1811 ◽

1996 ◽

Vol 122 (6) ◽

pp. 1811-1819 ◽

Cited By ~ 12

Author(s):

F.M. Carland ◽

N.A. McHale

Keyword(s):

Cell Expansion ◽

Higher Plants ◽

Lateral Roots ◽

Primary Root ◽

Vascular Patterning ◽

Basipetal Transport ◽

Leaf Mutant ◽

Identification And Characterization ◽

Axial Growth

We have taken a genetic approach to understanding the mechanisms that control vascular patterning in the leaves of higher plants. Here we present the identification and characterization of the lop1 mutant of Arabidopsis which is defective in basipetal transport of IAA. Mutant leaf midveins show disoriented axial growth, and bifurcation into twin veins that are frequently rotated out of the normal dorsal/ventral axis of the leaf. Mutant plants also display abnormal patterns of cell expansion in the midrib cortex and in the epidermis of the elongation zone of lateral roots. Lateral roots show abnormal curvature during initiation, sometimes encircling the primary root prior to growth in a normal downward direction. Mutant seedlings have normal levels of free IAA, and appear normal in auxin perception, suggesting that transport is the primary lesion. The abnormalities in vascular development, lateral root initiation and patterns of cell expansion observed in the lop] mutant are consistent with a basic disruption in basipetal transport of IAA.

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Effects of Phosphate Shortage on Root Growth and Hormone Content of Barley Depend on Capacity of the Roots to Accumulate ABA

Plants ◽

10.3390/plants9121722 ◽

2020 ◽

Vol 9 (12) ◽

pp. 1722

Author(s):

Lidiya Vysotskaya ◽

Guzel Akhiyarova ◽

Arina Feoktistova ◽

Zarina Akhtyamova ◽

Alla Korobova ◽

...

Keyword(s):

Root Growth ◽

Lateral Roots ◽

Primary Root ◽

Growth Responses ◽

Root Tips ◽

P Deficiency ◽

Root Branching ◽

Auxin Concentration ◽

Shoot Mass ◽

Primary Root Length

Although changes in root architecture in response to the environment can optimize mineral and water nutrient uptake, mechanisms regulating these changes are not well-understood. We investigated whether P deprivation effects on root development are mediated by abscisic acid (ABA) and its interactions with other hormones. The ABA-deficient barley mutant Az34 and its wild-type (WT) were grown in P-deprived and P-replete conditions, and hormones were measured in whole roots and root tips. Although P deprivation decreased growth in shoot mass similarly in both genotypes, only the WT increased primary root length and number of lateral roots. The effect was accompanied by ABA accumulation in root tips, a response not seen in Az34. Increased ABA in P-deprived WT was accompanied by decreased concentrations of cytokinin, an inhibitor of root extension. Furthermore, P-deficiency in the WT increased auxin concentration in whole root systems in association with increased root branching. In the ABA-deficient mutant, P-starvation failed to stimulate root elongation or promote branching, and there was no decline in cytokinin and no increase in auxin. The results demonstrate ABA’s ability to mediate in root growth responses to P starvation in barley, an effect linked to its effects on cytokinin and auxin concentrations.

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Rice OsDOF15 contributes to ethylene‐inhibited primary root elongation under salt stress

New Phytologist ◽

10.1111/nph.15824 ◽

2019 ◽

Vol 223 (2) ◽

pp. 798-813 ◽

Cited By ~ 10

Author(s):

Hua Qin ◽

Juan Wang ◽

Xinbing Chen ◽

Fangfang Wang ◽

Peng Peng ◽

...

Keyword(s):

Salt Stress ◽

Root Elongation ◽

Primary Root

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Overexpression of a Novel Component Induces HAK5 and Enhances Growth in Arabidopsis

ISRN Botany ◽

10.1155/2014/490252 ◽

2014 ◽

Vol 2014 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Eri Adams ◽

Celine Diaz ◽

Minami Matsui ◽

Ryoung Shin

Keyword(s):

Arabidopsis Thaliana ◽

Salt Stress ◽

Adaptive Response ◽

Screening Method ◽

Primary Root ◽

Nutrient Deficiency ◽

Potassium Deficiency ◽

Low Potassium ◽

Primary Root Growth ◽

Gene Hunting

Plants have developed mechanisms to adapt to the potassium deficient conditions over the years. In Arabidopsis thaliana, expression of a potassium transporter HAK5 is induced in low potassium conditions as an adaptive response to nutrient deficiency. In order to understand the mechanism in which HAK5 is regulated, the full-length cDNA overexpressor gene hunting system was employed as a screening method. Of 40 genes recovered, At4g18280 was found to be dramatically induced in response to potassium-deficiency and salt stress. Plants overexpressing this gene showed higher HAK5 expression and enhanced growth. These plants were also less sensitive to potassium-deficiency in terms of primary root growth. Taken together, these data suggest that this novel component, At4g18280, contributes to regulation of HAK5 and, consequently, tolerance to potassium-deficiency in plants.

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Corrigendum - Factors which affects the growth of grain legumes on a solonized brown soil. I. Genotypic responses to soil physical factors

Australian Journal of Agricultural Research ◽

10.1071/ar9910095c ◽

1991 ◽

Vol 42 (1) ◽

pp. 95

Author(s):

BJ Atwell

Keyword(s):

Root Growth ◽

Water Status ◽

Lateral Roots ◽

Primary Root ◽

Grain Legumes ◽

Root Tip ◽

Physical Factors ◽

Brown Soil ◽

Penetrometer Resistance ◽

System L

Lupins (Lupinus angustifolius cvv. Yandee and 75A-258 and L. pilosus cv. P. 20957) and pea (Pisum sativum cv. Dundale) were grown in the field for 43 days on a solonized brown soil. Shoots of L. pilosus and peas grew most rapidly, while L. angustifolius cv. 75A-258 developed a relatively large root system. L. angustifolius cv. Yandee, a commercial lupin cultivar, was poorly adapted; shoot growth was restricted and roots ceased growing 36 days after sowing. The soil factors responsible for these widely differing responses were investigated. Once primary roots of L. angustifolius were 20-30 cm deep, root extension was slow or arrested. Indeed, primary root apices of Yandee were often necrotic in the soil below 20 cm. In contrast, roots proliferated rapidly in the surface 20 cm of the soil, particularly in 7SA-258, suggesting that factors in the deeper soil layers restricted root growth most severely. The vigorous growth of lateral roots of 75A-258 was reflected in a 2.6 fold greater total root length than for Yandee 43 days after sowing. Soil physical properties were not considered a likely explanation for these observations; soil water status and porosity were always favourable for root growth and root sections indicated that no cortical degradation, typical of O2 deficient roots, had occurred. Penetrometer resistance and root tip osmotic pressures suggested that poor root growth could not be ascribed simply to soil mechanical properties. The results suggest, by inference, that soil chemical factors could underlie the phenotypic responses observed.

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Overexpression of the Auxin Receptor AFB3 in Arabidopsis Results in Salt Stress Resistance and the Modulation of NAC4 and SZF1

International Journal of Molecular Sciences ◽

10.3390/ijms21249528 ◽

2020 ◽

Vol 21 (24) ◽

pp. 9528

Author(s):

Fernanda Garrido-Vargas ◽

Tamara Godoy ◽

Ricardo Tejos ◽

José Antonio O’Brien

Keyword(s):

Salt Stress ◽

Stress Response ◽

Growth And Development ◽

Root Architecture ◽

Crop Production ◽

Lateral Roots ◽

Auxin Signaling ◽

Auxin Receptor ◽

Salt Stress Response ◽

Regulatory Pathways

Soil salinity is a key problem for crop production worldwide. High salt concentration in soil negatively modulates plant growth and development. In roots, salinity affects the growth and development of both primary and lateral roots. The phytohormone auxin regulates various developmental processes during the plant’s life cycle, including several aspects of root architecture. Auxin signaling involves the perception by specialized receptors which module several regulatory pathways. Despite their redundancy, previous studies have shown that their functions can also be context-specific depending on tissue, developmental or environmental cues. Here we show that the over-expression of Auxin Signaling F-Box 3 receptor results in an increased resistance to salinity in terms of root architecture and germination. We also studied possible downstream signaling components to further characterize the role of auxin in response to salt stress. We identify the transcription factor SZF1 as a key component in auxin-dependent salt stress response through the regulation of NAC4. These results give lights of an auxin-dependent mechanism that leads to the modulation of root system architecture in response to salt identifying a hormonal cascade important for stress response.

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Effect of organic pollutant treatment on the growth of pea and maize seedlings

Open Life Sciences ◽

10.2478/s11535-011-0081-1 ◽

2012 ◽

Vol 7 (1) ◽

pp. 159-166 ◽

Cited By ~ 7

Author(s):

Marie Kummerová ◽

Štěpán Zezulka ◽

Lucie Váňová ◽

Helena Fišerová

Keyword(s):

Zea Mays ◽

Seed Germination ◽

Lateral Roots ◽

Organic Pollutant ◽

Primary Root ◽

Dry Weight ◽

Considerable Effect ◽

Maize Seedlings ◽

Polycyclic Aromatic ◽

Primary And Lateral Roots

AbstractThis study confirmed the considerable effect of polycyclic aromatic hydrocarbon fluoranthene (FLT; 0.01, 0.1, 1, 4 and 7 mg/l) exposure on the germination of seeds, growth and root morphology of seedlings in Zea mays and Pisum sativum. Seed germination was significantly inhibited at FLT≥0.01 mg/l in maize and at ≥1 mg/l in pea. The amount of released ethylene after 3 days of germination was significantly increased in both species at FLT≥0.1 mg/l. After 7 days of seedling cultivation a significant decrease in the dry weight of roots and shoots occurred in maize at FLT≥0.1 mg/l while in pea similar effect was observed at ≥1 mg/l. The total length of primary and lateral roots was significantly reduced by FLT≥1 mg/l in maize and by 4 and 7 mg/l in pea. The length of the non-branched part of the primary root was significantly reduced by FLT≥0.1 mg/l in maize and ≥0.01 mg/l in pea. In both species the number of lateral roots was significantly increased at FLT≤1 mg/l and inhibited at concentrations of 4 and 7 mg/l. Fluoranthene content in roots and shoots of both species positively correlated with the FLT treatment.

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