The Role of Root Apices in Shoot Growth Regulation: Support for Neurobiology at the Whole Plant Level?

Communication in Plants ◽

10.1007/3-540-28516-4_5 ◽

2006 ◽

pp. 65-73

Author(s):

Peter M. Neumann

Keyword(s):

Growth Regulation ◽

Shoot Growth ◽

Whole Plant ◽

Plant Level ◽

Root Apices

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Autophagy Controls Sulphur Metabolism in the Rosette Leaves of Arabidopsis and Facilitates S Remobilization to the Seeds

Cells ◽

10.3390/cells9020332 ◽

2020 ◽

Vol 9 (2) ◽

pp. 332 ◽

Cited By ~ 5

Author(s):

Aurélia Lornac ◽

Marien Havé ◽

Fabien Chardon ◽

Fabienne Soulay ◽

Gilles Clément ◽

...

Keyword(s):

Nutrient Recycling ◽

Industrial Plants ◽

Sulphur Nutrition ◽

Whole Plant ◽

Acid Accumulation ◽

Salicylic Acid Accumulation ◽

Plant Level ◽

And Control ◽

S Deposition

Sulphur deficiency in crops became an agricultural concern several decades ago, due to the decrease of S deposition and the atmospheric sulphur dioxide emissions released by industrial plants. Autophagy, which is a conserved mechanism for nutrient recycling in eukaryotes, is involved in nitrogen, iron, zinc and manganese remobilizations from the rosette to the seeds in Arabidopsis thaliana. Here, we have compared the role of autophagy in sulphur and nitrogen management at the whole plant level, performing concurrent labelling with 34S and 15N isotopes on atg5 mutants and control lines. We show that both 34S and 15N remobilizations from the rosette to the seeds are impaired in the atg5 mutants irrespective of salicylic acid accumulation and of sulphur nutrition. The comparison in each genotype of the partitions of 15N and 34S in the seeds (as % of the whole plant) indicates that the remobilization of 34S to the seeds was twice more efficient than that of 15N in both autophagy mutants and control lines under high S conditions, and also in control lines under low S conditions. This was different in the autophagy mutants grown under low S conditions. Under low S, the partition of 34S to their seeds was indeed not twice as high but similar to that of 15N. Such discrepancy shows that when sulphate availability is scarce, autophagy mutants display stronger defects for 34S remobilization relative to 15N remobilization than under high S conditions. It suggests, moreover, that autophagy mainly affects the transport of N-poor S-containing molecules and possibly sulphate.

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Gossypium Herbaceum Ghcyp1 Regulates Water-Use Efficiency and Drought Tolerance by Modulating Stomatal Activity and Photosynthesis in Transgenic Tobacco

Biosciences Biotechnology Research Asia ◽

10.13005/bbra/2520 ◽

2017 ◽

Vol 14 (3) ◽

pp. 869-880 ◽

Cited By ~ 1

Author(s):

Alok Ranjan ◽

Kumari Archana ◽

Sanjay Ranjan

Keyword(s):

Water Use ◽

Abiotic Stress Tolerance ◽

Leaf Disc ◽

Proline Content ◽

Whole Plant ◽

Drought And Salt Stress ◽

Rate Of Photosynthesis ◽

Physiological Homeostasis ◽

Plant Level

ABSTRACT: The cyclophilins genes are induced by abiotic stresses, yet their detailed function in drought and salinity remain largely unclear and need to be elaborately validated.Expression of cyclophilin was drastically induced under droughtconditions in Gossypiumherbaceum L. suggesting its stress-responsive function. In an attempt to characterize the role of G.herbacuemcyclophilingene GhCYP1, we overexpressed the GhCYP1 in tobaccousing Agrobacteriummediated transformationand explored its possible involvement in drought and salt stress tolerance.The transgenic plantsover expressing GhCYP1 exhibited tolerance against drought stress as evidenced by leaf disc assay, estimation of chlorophylland proline content along with various physiological parameters such as stomatal conductance, rate of photosynthesis and water use efficiency.The drought stressed transgenic tobaccoplants exhibited higher proline content in leaf ( 1.84 µ mol-g fw) and root (2.02µ mol-g fw ),while a reverse trend was observed in the drought stressed wild type plants, implicating the involvement of GhCYP1 in the maintenance of physiological homeostasis. Thedetail physiological, biochemical and molecular analysis results demonstrate the implicit role of GhCYP1 in conferring multiple abiotic stress tolerance at whole-plant level.

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Molecular Dialog between Root and Shoot via Regulatory Peptides and Its Role in Systemic Control of Plant Development

Russian Journal of Plant Physiology ◽

10.1134/s1021443720060114 ◽

2020 ◽

Vol 67 (6) ◽

pp. 985-1002 ◽

Cited By ~ 1

Author(s):

M. A. Lebedeva ◽

Ya. S. Yashenkova ◽

I. E. Dodueva ◽

L. A. Lutova

Keyword(s):

Regulatory Peptides ◽

Water Deficiency ◽

Nitrogen And Phosphorus ◽

Systemic Control ◽

Arbuscular Mycorrhiza Fungi ◽

Whole Plant ◽

Specific Receptors ◽

Plant Level ◽

Soil Influence

Abstract Plant developmental processes are very flexible and highly depend on environmental factors. This is largely due to the existence of regulatory mechanisms that systemically control development on the whole plant level. In plants, regulatory peptides produced in the roots have been identified that are activated in response to different factors influencing root system, such as variation in the level of macronutrients (first of all, nitrogen and phosphorus) in the soil, influence of symbiotic microorganisms (soil rhizobial bacteria and arbuscular mycorrhiza fungi), and water deficiency. Among the systemically acting peptides, the most thoroughly investigated are CLE (CLAVATA3/EMBRYO SURROUNDING REGION-related) and CEP (C-TERMINALLY ENCODED PEPTIDES) peptides that are capable of travelling through the xylem from the roots to the shoot and triggering responses via binding to specific receptors operating in the phloem of the leaf. This review focuses on the role of these two groups of peptides in molecular dialog between the root and shoot.

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Cut and paste – Efficient cotyledon micrografting for Arabidopsis thaliana seedlings

10.1101/751677 ◽

2019 ◽

Author(s):

Kai Bartusch ◽

Jana Trenner ◽

Marcel Quint

Keyword(s):

Arabidopsis Thaliana ◽

Success Rates ◽

Long Distance ◽

Long Distance Transport ◽

Light Intensities ◽

Whole Plant ◽

Plant Level ◽

Distance Transport ◽

Plant Seedlings

AbstractCotyledon micrografting represents a very useful tool for studying the central role of cotyledons during early plant development, especially their interplay with other plant organs with regard to long distance transport. While hypocotyl grafting methods are established, cotyledon grafting is still inefficient. By optimizing cotyledon micrografting, we aim for higher success rates and increased throughput in the model species Arabidopsis thaliana. We established a cut and paste cotyledon surgery procedure on a flat solid but moist surface which improved handling of small plant seedlings. Applying a specific cutting and joining pattern throughput was increased up to 40 seedlings per hour. The combination of short day conditions and low light intensities for germination and long day plus high light intensities and vertical plate positioning after grafting significantly increased ‘ligation’ efficiency. Together, we achieved up to 46 % grafting success in A. thaliana. Reconnection of vasculature was shown by successful transport of a vasculature-specific dye across the grafting site. On a whole plant level, plants with grafted cotyledons match plants with intact cotyledons in biomass production and rosette development. This cut and paste cotyledon-to-petiole grafting protocol simplifies the handling of plant seedlings in surgery, increases the number of grafted plants per hour and produces higher success rates for A. thaliana seedlings. The developed cotyledon micrografting method is also suitable for other plant species of comparable size.

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RNAs 1 and 2 of Alfalfa mosaic virus, expressed in transgenic plants, start to replicate only after infection of the plants with RNA 3

Journal of General Virology ◽

10.1099/0022-1317-82-1-25 ◽

2001 ◽

Vol 82 (1) ◽

pp. 25-28 ◽

Cited By ~ 6

Author(s):

Vera Thole ◽

Maria-Laura Garcia ◽

Clemens M. A. van Rossum ◽

Lyda Neeleman ◽

Frans T. Brederode ◽

...

Keyword(s):

Mosaic Virus ◽

Rna Synthesis ◽

Alfalfa Mosaic Virus ◽

Transgenic Expression ◽

Whole Plant ◽

Transgenic Lines ◽

Viral Replicase ◽

Plant Level ◽

First Time

RNAs 1 and 2 of the tripartite genome of Alfalfa mosaic virus (AMV) encode the two viral replicase subunits. Full-length DNA copies of RNAs 1 and 2 were used to transform tobacco plants (R12 lines). None of the transgenic lines showed resistance to AMV infection. In healthy R12 plants, the transcripts of the viral cDNAs were copied by the transgenic viral replicase into minus-strand RNAs but subsequent steps in replication were blocked. When the R12 plants were inoculated with AMV RNA 3, this block was lifted and the transgenic RNAs 1 and 2 were amplified by the transgenic replicase together with RNA 3. The transgenic expression of RNAs 1 and 2 largely circumvented the role of coat protein (CP) in the inoculum that is required for infection of nontransgenic plants. The results for the first time demonstrate the role of CP in AMV plus-strand RNA synthesis at the whole plant level.

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Trehalose and trehalose-6-phosphate induce stomatal movements and interfere with ABA-induced stomatal closure in grapevine

OENO One ◽

10.20870/oeno-one.2015.49.3.84 ◽

2015 ◽

Vol 49 (3) ◽

pp. 165 ◽

Cited By ~ 3

Author(s):

Magdalena Gamm ◽

Marie-Claire Héloir ◽

Marielle Adrian

Keyword(s):

Stomatal Closure ◽

Guard Cells ◽

Oxygen Species ◽

Light Conditions ◽

Whole Plant ◽

Low Concentrations ◽

Stomatal Movements ◽

Plant Level ◽

First Time

Aims: The effects of trehalose and trehalose-6-phosphate (T6P), among other sugars, were assessed on grapevine stomatal movements.Methods and results: Epidermal peels were used to assess the effects of sugars. Low concentrations of trehalose and T6P (1 µM) induced an osmotic-independent reduction of the stomatal aperture in light conditions. Furthermore, ABA-induced stomatal closure was reduced by sugar application in association with lower accumulation of reactive oxygen species in guard cells. Similar effects, although weaker, were observed in response to the disaccharides sucrose and maltose, but not in response to the monosaccharides fructose and glucose.Conclusion: This study clearly highlights the effects of sugars, especially trehalose and T6P, on grapevine stomatal movements.Significance and impact of the study: This is the first time that such effects are described in grapevine and the results obtained provide new insights about the role of sugars on stomatal regulation at the whole plant level.

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Medicago truncatula response to water-deficit stress: whole plant perspectives

10.48035/tesis/2454/41129 ◽

2021 ◽

Author(s):

◽

Verónica Castañeda Presa

Keyword(s):

Water Deficit ◽

Medicago Truncatula ◽

Water Status ◽

Water Deficit Stress ◽

World Population ◽

Fibrous Root ◽

Model Plant ◽

Whole Plant ◽

Plant Level

Medicago truncatula is a forage legume with agricultural but also scientifical interest, being used as a model plant for the study of legumes’ biology. Within a climate change context, it is of great importance to maintain/increase plant yield in stressful growth conditions to meet the requirements of the increasing world population. In order to achieve this, it is mandatory to further understand the adaptive response of plants to water-deficit stress, for which the use of this model plant results of great utility. In the present study, the simultaneous study of various plant organs with particular focus on the root system allows us a more integrative understanding of water-deficit response mechanisms from a whole-plant perspective. The root tissue was studied in Chapter 1, distinguishing between the thick taproot and the much thinner fibrous root. The different behaviour of both root types under well-watered as well as under water-deficit conditions was studied from a physiological and metabolic perspec-tive. This study highlighted the active role of the taproot rather than being considered a mere nutrient storage organ. The taproot showed a more resilient nature towards water-deficit stress than the fibrous root, while sucrose cleavage modulation, together with proline metabolism sug-gested a crucial role of these pathways in the root adaptation to water-deficit stress. In Chapter 2 we aimed to address different water-deficit conditions that can affect plant water status, using iso-osmotical conditions of salinity (NaCl and KCl), lack of irrigation and an osmoticum (PEG). This approach allows us to identify the similarities and differences in the mechanisms involved in the response to each stress at the whole-plant level. While PEG was dismissed as a reliable drought-stress mimicker, NaCl and KCl led to similar responses, with a slightly higher negative effect of KCl on plant metabolism. On the other hand, an emphasis on the shoot and root protection was observed for NaCl and no-irrigation stress, respectively. The study of the phloem sap allowed us to better understand the responses to the different water-deficit conditions at a whole-plant level. In summary, this study provides further insight into the response at the whole-plant level of M. truncatula to water-deficit conditions from a biochemical, metabolic and physiological point of view.

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Sirtuin 1 and Sirtuin 3 in Granulosa Cell Tumors

International Journal of Molecular Sciences ◽

10.3390/ijms22042047 ◽

2021 ◽

Vol 22 (4) ◽

pp. 2047

Author(s):

Nina Schmid ◽

Kim-Gwendolyn Dietrich ◽

Ignasi Forne ◽

Alexander Burges ◽

Magdalena Szymanska ◽

...

Keyword(s):

Cell Proliferation ◽

Granulosa Cell ◽

Granulosa Cells ◽

Drug Targets ◽

Growth Regulation ◽

Sirtuin 1 ◽

Ki 67 ◽

Granulosa Cell Tumors ◽

Novel Drug

Sirtuins (SIRTs) are NAD+-dependent deacetylases that regulate proliferation and cell death. In the human ovary, granulosa cells express sirtuin 1 (SIRT1), which has also been detected in human tumors derived from granulosa cells, i.e., granulosa cell tumors (GCTs), and in KGN cells. KGN cells are an established cellular model for the majority of GCTs and were used to explore the role of SIRT1. The SIRT1 activator SRT2104 increased cell proliferation. By contrast, the inhibitor EX527 reduced cell numbers, without inducing apoptosis. These results were supported by the outcome of siRNA-mediated silencing studies. A tissue microarray containing 92 GCTs revealed nuclear and/or cytoplasmic SIRT1 staining in the majority of the samples, and also, SIRT2-7 were detected in most samples. The expression of SIRT1–7 was not correlated with the survival of the patients; however, SIRT3 and SIRT7 expression was significantly correlated with the proliferation marker Ki-67, implying roles in tumor cell proliferation. SIRT3 was identified by a proteomic analysis as the most abundant SIRT in KGN. The results of the siRNA-silencing experiments indicate involvement of SIRT3 in proliferation. Thus, several SIRTs are expressed by GCTs, and SIRT1 and SIRT3 are involved in the growth regulation of KGN. If transferable to GCTs, these SIRTs may represent novel drug targets.

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