scholarly journals Auxin and Target of Rapamycin Spatiotemporally Regulate Root Organogenesis

2021 ◽  
Vol 22 (21) ◽  
pp. 11357
Author(s):  
Xiulan Xie ◽  
Ying Wang ◽  
Raju Datla ◽  
Maozhi Ren
Keyword(s):  
Root Development ◽  
Lateral Roots ◽  
Target Of Rapamycin ◽  
Tor Signaling ◽  
Root Functions ◽  
Primary Roots ◽  
Functional Implications ◽  
Root Organogenesis ◽  
Root Morphogenesis ◽  
Photosynthetic Products

The programs associated with embryonic roots (ERs), primary roots (PRs), lateral roots (LRs), and adventitious roots (ARs) play crucial roles in the growth and development of roots in plants. The root functions are involved in diverse processes such as water and nutrient absorption and their utilization, the storage of photosynthetic products, and stress tolerance. Hormones and signaling pathways play regulatory roles during root development. Among these, auxin is the most important hormone regulating root development. The target of rapamycin (TOR) signaling pathway has also been shown to play a key role in root developmental programs. In this article, the milestones and influential progress of studying crosstalk between auxin and TOR during the development of ERs, PRs, LRs and ARs, as well as their functional implications in root morphogenesis, development, and architecture, are systematically summarized and discussed.

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.

Early Pinus caribaea var. hondurensis root development. 2. Influence of soil strength

1996 ◽  
Vol 36 (7) ◽  
pp. 847 ◽  
Author(s):  
A Costantini ◽  
D Doley ◽  
HB So
Keyword(s):  
Root Development ◽  
Soil Type ◽  
Root Elongation ◽  
Primary Root ◽  
High Strength ◽  
Soil Strength ◽  
Shoot Development ◽  
Pinus Caribaea ◽  
Primary Shoot ◽  
Primary Roots

The influence of penetration resistance (PR), an easily measured indicator of soil strength, on the growth of Pinus caribaea var. hondurensis radicles and seedlings was investigated. Negative exponential relationships between PR and both radicle and primary root elongation were observed. All root elongation ceased at PR levels of 3.25 MPa. Tip diameters of radicles and primary roots were positively correlated with PR values up to 2.4 MPa, whilst numbers of primary roots, total root lengths and lengths of longest roots were all negatively correlated with PR. Hypocotyl elongation was also reduced by increasing PR, although the reductions occurred at higher PRs than those which inhibited root development. In contrast, primary shoot development was unaffected by PR levels which were sufficient to stop root elongation, but was reduced in soil with a PR of 4.8 MPa. There were significant family x soil type and family x PR interactions for radicle, hypocotyl, primary root and primary shoot development. 1f these interactions are correlated with performance in the field, then they may serve as useful indicators of family suitability to both soil type and high strength soils.

Interaction of silicon and cadmium in Brassica juncea and Brassica napus

Biologia ◽  
2012 ◽  
Vol 67 (3) ◽  
Author(s):  
Zuzana Vatehová ◽  
Karin Kollárová ◽  
Ivan Zelko ◽  
Danica Richterová-Kučerová ◽  
Marek Bujdoš ◽  
...  
Keyword(s):  
Lateral Roots ◽  
Root Apex ◽  
Brassica Species ◽  
Inhibitory Effects ◽  
Cd Uptake ◽  
Primary Roots ◽  
Suberin Lamellae ◽  
Root And Shoot Growth ◽  
The Impact ◽  
Si Addition

AbstractThe objective of this study was to determine the effect of silicon (Si) and cadmium (Cd) on root and shoot growth and Cd uptake in two hydroponically cultivated Brassica species (B. juncea (L.) Czern. cv. Vitasso and B. napus L. cv. Atlantic). Both species are potentially usable for phytoextraction. Inhibitory effects of Cd on root elongation were diminished by the impact of Si. Primary roots elongation in the presence of Cd + Si compared with Cd was stronger and the number of lateral roots was lower in B. juncea than in B. napus. Cd content per plant was higher in B. napus roots and shoots compared with B. juncea. Suberin lamellae were formed closer to the root apex in Cd + Si than in Cd treated plants and this effect was stronger in B. napus than in B. juncea. Accelerated maturation of endodermis was associated with reduced Cd uptake. Cd decreased the content of chlorophylls and carotenoids in both species, but Si addition positively influenced the content of photosynthetic pigments which was higher in B. napus than in B. juncea. Si enhanced more substantially translocation of Cd into the shoot of B. napus than of B. juncea. Based on our results B. napus seems to be more suitable for Cd phytoextraction than B. juncea because these plants produce more biomass and accumulate higher amount of Cd. The protective effect of Si on Cd treated Brassica plants could be attributed to more extensive development of suberin lamellae in endodermis.

TOR at the core of impaired regeneration

2018 ◽  
Vol 10 (422) ◽  
pp. eaar7508
Author(s):  
Christopher Hine
Keyword(s):  
Stem Cell ◽  
Tissue Regeneration ◽  
Target Of Rapamycin ◽  
Tor Signaling ◽  
Stem Cell Maintenance ◽  
The Core ◽  
Cell Maintenance

Repeated activation of target of rapamycin (TOR) signaling during tissue regeneration results in impaired stem cell maintenance and promotes aging.

scholarly journals Photoperiod and temperature separately regulate nymphal development through JH and insulin/TOR signaling pathways in an insect

2020 ◽  
Vol 117 (10) ◽  
pp. 5525-5531 ◽  
Author(s):  
Taiki Miki ◽  
Tsugumichi Shinohara ◽  
Silvia Chafino ◽  
Sumihare Noji ◽  
Kenji Tomioka
Keyword(s):  
Growth Rate ◽  
Juvenile Hormone ◽  
Signaling Pathway ◽  
Slow Growth ◽  
Physiological State ◽  
Target Of Rapamycin ◽  
Tor Signaling ◽  
Seasonal Adaptation ◽  
Nymphal Stage ◽  
Nymphal Development

Insects living in the temperate zone enter a physiological state of arrested or slowed development to overcome an adverse season, such as winter. Developmental arrest, called diapause, occurs at a species-specific developmental stage, and embryonic and pupal diapauses have been extensively studied in mostly holometabolous insects. Some other insects overwinter in the nymphal stage with slow growth for which the mechanism is poorly understood. Here, we show that this nymphal period of slow growth is regulated by temperature and photoperiod through separate pathways in the cricket Modicogryllus siamensis. The former regulates the growth rate, at least in part, through the insulin / target of rapamycin (TOR) signaling pathway. Lower temperature down-regulates the expression of insulin-like peptide (Ms’Ilp) and Target of rapamycin (Ms’Tor) genes to slow down the growth rate without affecting the number of molts. The latter regulates the number of molts independent of temperature. Short days increase the number of molts through activation of the juvenile hormone (JH) pathway and down-regulation of myoglianin (Ms’myo), a member of the TGFβ family, which induces adult metamorphosis. In contrast, long days regulate Ms’myo expression to increase during the fifth to sixth instar to initiate adult metamorphosis. When Ms’myo expression is suppressed, juvenile hormone O-methyl transferase (Ms’jhamt) was up-regulated and increased molts to prolong the nymphal period even under long-day conditions. The present findings suggested that the photoperiod regulated Ms’myo, and the JH signaling pathway and the temperature-controlled insulin/TOR pathway cooperated to regulate nymphal development for overwintering to achieve seasonal adaptation of the life cycle in M. siamensis.

scholarly journals The Plant Target of Rapamycin: A Conduc TOR of Nutrition and Metabolism in Photosynthetic Organisms

Genes ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1285
Author(s):  
Camille Ingargiola ◽  
Gustavo Turqueto Duarte ◽  
Christophe Robaglia ◽  
Anne-Sophie Leprince ◽  
Christian Meyer
Keyword(s):  
Target Of Rapamycin ◽  
Plant Responses ◽  
Tor Signaling ◽  
Biotic And Abiotic Stresses ◽  
Extrinsic Factors ◽  
Tor Pathway ◽  
Photosynthetic Organisms ◽  
Unicellular Algae ◽  
Living Organisms ◽  
Favorable Conditions

Living organisms possess many mechanisms to sense nutrients and favorable conditions, which allow them to grow and develop. Photosynthetic organisms are very diverse, from green unicellular algae to multicellular flowering plants, but most of them are sessile and thus unable to escape from the biotic and abiotic stresses they experience. The Target of Rapamycin (TOR) signaling pathway is conserved in all eukaryotes and acts as a central regulatory hub between growth and extrinsic factors, such as nutrients or stress. However, relatively little is known about the regulations and roles of this pathway in plants and algae. Although some features of the TOR pathway seem to have been highly conserved throughout evolution, others clearly differ in plants, perhaps reflecting adaptations to different lifestyles and the rewiring of this primordial signaling module to adapt to specific requirements. Indeed, TOR is involved in plant responses to a vast array of signals including nutrients, hormones, light, stresses or pathogens. In this review, we will summarize recent studies that address the regulations of TOR by nutrients in photosynthetic organisms, and the roles of TOR in controlling important metabolic pathways, highlighting similarities and differences with the other eukaryotes.

scholarly journals 10-Hydroxy-2-decenoic Acid, the Major Lipid Component of Royal Jelly, Extends the Lifespan ofCaenorhabditis elegansthrough Dietary Restriction and Target of Rapamycin Signaling

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Yoko Honda ◽  
Yoko Araki ◽  
Taketoshi Hata ◽  
Kenji Ichihara ◽  
Masafumi Ito ◽  
...  
Keyword(s):  
Dietary Restriction ◽  
Royal Jelly ◽  
Target Of Rapamycin ◽  
Control Mechanisms ◽  
Tor Signaling ◽  
Decenoic Acid ◽  
C Elegans ◽  
Lipid Component ◽  
Extended Lifespan ◽  
And Oxidative Stress

Royal jelly (RJ) produced by honeybees has been reported to possess diverse health-beneficial properties and has been implicated to have a function in longevity across diverse species as well as honeybees. 10-Hydroxy-2-decenoic acid (10-HDA), the major lipid component of RJ produced by honeybees, was previously shown to increase the lifespan ofCaenorhabditis elegans.The objective of this study is to elucidate signaling pathways that are involved in the lifespan extension by 10-HDA. 10-HDA further extended the lifespan of thedaf-2mutants, which exhibit long lifespan through reducing insulin-like signaling (ILS), indicating that 10-HDA extended lifespan independently of ILS. On the other hand, 10-HDA did not extend the lifespan of theeat-2mutants, which show long lifespan through dietary restriction caused by a food-intake defect. This finding indicates that 10-HDA extends lifespan through dietary restriction signaling. We further found that 10-HDA did not extend the lifespan of the long-lived mutants indaf-15, which encodes Raptor, a target of rapamycin (TOR) components, indicating that 10-HDA shared some longevity control mechanisms with TOR signaling. Additionally, 10-HDA was found to confer tolerance against thermal and oxidative stress. 10-HDA increases longevity not through ILS but through dietary restriction and TOR signaling inC. elegans.

scholarly journals Expression Studies on AUX1-like Genes in Medicago truncatula Suggest That Auxin Is Required at Two Steps in Early Nodule Development

2001 ◽  
Vol 14 (3) ◽  
pp. 267-277 ◽  
Author(s):  
Françoise de Billy ◽  
Cathy Grosjean ◽  
Sean May ◽  
Malcolm Bennett ◽  
Julie V. Cullimore
Keyword(s):  
Medicago Truncatula ◽  
Lateral Root ◽  
Sequence Similarity ◽  
Lateral Roots ◽  
Peripheral Region ◽  
Nodule Development ◽  
Central Position ◽  
Root Tips ◽  
High Sequence Similarity ◽  
Primary Roots

Medicago truncatula contains a family of at least five genes related to AUX1 of Arabidopsis thaliana (termed MtLAX genes for Medicago truncatula-like AUX1 genes). The high sequence similarity between the encoded proteins and AUX1 implies that the MtLAX genes encode auxin import carriers. The MtLAX genes are expressed in roots and other organs, suggesting that they play pleiotropic roles related to auxin uptake. In primary roots, the MtLAX genes are expressed preferentially in the root tips, particularly in the provascular bundles and root caps. During lateral root and nodule development, the genes are expressed in the primordia, particularly in cells that were probably derived from the pericycle. At slightly later stages, the genes are expressed in the regions of the developing organs where the vasculature arises (central position for lateral roots and peripheral region for nodules). These results are consistent with MtLAX being involved in local auxin transport and suggest that auxin is required at two common stages of lateral root and nodule development: development of the primordia and differentiation of the vasculature.

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