Rhizobium-induced elevation in xylem cytokinin delivery in pigeonpea induces changes in shoot development and leaf physiology

2014 ◽  
Vol 41 (12) ◽  
pp. 1323 ◽  
Author(s):  
Jean W. H. Yong ◽  
D. Stuart Letham ◽  
S. Chin Wong ◽  
Graham D. Farquhar
Keyword(s):  
Xylem Sap ◽  
Shoot Development ◽  
Leaf Thickness ◽  
High Nitrogen ◽  
N Nutrition ◽  
Leaf Physiology ◽  
Lateral Buds ◽  
Curled Leaves ◽  
Leaf Curl

Inoculation with Rhizobium strain IC3342 induces in pigeonpea (Cajanus cajan (L) Millsp.) a leaf curl syndrome and elevated cytokinin levels in the xylem sap. High nitrogen (N) nutrition was found to inhibit onset of the syndrome which could then be induced by N-free nutrient after development of seven trifoliate leaves. This provided a new system to study the role of xylem cytokinin in shoot development and yielded plants suitable for determining the rate of delivery of xylem cytokinin to the shoot which for IC3342-inoculated plants was found to be three times that of control plants. Relative to leaves of control plants, the non-curled leaves of these IC3342 plants exhibited higher nitrogen and chlorophyll content and greater photosynthetic rate and stomatal conductance. Induction of the syndrome increased leaf thickness in developing leaves but not in expanded leaves already formed. Diameter of stems and number of laterals were also increased markedly by IC3342 inoculation which in addition induced leaf hyponasty. Exogenous cytokinins when applied directly to control leaves induced leaf curl and increased leaf thickness. The present studies are discussed in relation to the role of xylem cytokinins in plant development and especially the release of lateral buds from apical dominance.

scholarly journals Shoot–root carbon allocation, sugar signalling and their coupling with nitrogen uptake and assimilation

2016 ◽  
Vol 43 (2) ◽  
pp. 105 ◽  
Author(s):  
Lu Wang ◽  
Yong-Ling Ruan
Keyword(s):  
Growth And Development ◽  
Carbon Allocation ◽  
Dynamic Balance ◽  
Shoot Development ◽  
Long Distance ◽  
Root Carbon ◽  
Organ Systems ◽  
New Findings ◽  
Sugar Signalling

Roots and shoots are distantly located but functionally interdependent. The growth and development of these two organ systems compete for energy and nutrient resource, and yet, they keep a dynamic balance with each other for growth and development. The success of such a relationship depends on efficient root-shoot communication. Aside from the well-known signalling processes mediated by hormones such as auxin and cytokinin, sugars have recently been shown to act as a rapid signal to co-ordinate root and shoot development in response to endogenous and exogenous clues, in parallel to their function as carbon and energy resources for biomass production. New findings from studies on vascular fluids have provided molecular insights into the role of sugars in long-distance communications between shoot and root. In this review, we discussed phloem- and xylem- translocation of sugars and the impacts of sugar allocation and signalling on balancing root–shoot development. Also, we have taken the shoot–root carbon–nitrogen allocation as an example to illustrate the communication between the two organs through multi-layer root–shoot–root signalling circuits, comprising sugar, nitrogen, cytokinin, auxin and vascular small peptide signals.

scholarly journals Correction: Genetic Mapping Reveals Broader Role of Vrn-H3 Gene in Root and Shoot Development beyond Heading in Barley

PLoS ONE ◽  
2017 ◽  
Vol 12 (5) ◽  
pp. e0177612 ◽  
Author(s):  
Md. Arifuzzaman ◽  
Süleyman Günal ◽  
Annemarie Bungartz ◽  
Shumaila Muzammil ◽  
Nazanin P. Afsharyan ◽  
...  
Keyword(s):  
Genetic Mapping ◽  
Shoot Development

An investigation of the role of solutes in the xylem sap and in the xylem parenchyma as the source of root pressure

PROTOPLASMA ◽  
2000 ◽  
Vol 211 (3-4) ◽  
pp. 183-197 ◽  
Author(s):  
L. C. Enns ◽  
M. J. Canny ◽  
M. E. McCully
Keyword(s):  
Xylem Sap ◽  
Xylem Parenchyma ◽  
Root Pressure

Passivity of high-nitrogen stainless alloys: the role of metal oxyanions and salt films

1995 ◽  
Vol 198 (1-2) ◽  
pp. 135-144 ◽  
Author(s):  
Clive R. Clayton ◽  
Gary P. Halada ◽  
Jeffery R. Kearns
Keyword(s):  
High Nitrogen

scholarly journals Effects of Fire and Large Herbivores on Canopy Nitrogen in a Tallgrass Prairie

2019 ◽  
Vol 11 (11) ◽  
pp. 1364 ◽  
Author(s):  
Bohua Ling ◽  
Edward J. Raynor ◽  
Douglas G. Goodin ◽  
Anthony Joern
Keyword(s):  
Spatial Variability ◽  
Nitrogen Content ◽  
Tallgrass Prairie ◽  
High Nitrogen Content ◽  
High Nitrogen ◽  
Grazing History ◽  
One Year ◽  
Canopy Nitrogen

This study analyzed the spatial heterogeneity of grassland canopy nitrogen in a tallgrass prairie with different treatments of fire and ungulate grazing (long-term bison grazing vs. recent cattle grazing). Variogram analysis was applied to continuous remotely sensed canopy nitrogen images to examine the spatial variability in grassland canopies. Heterogeneity metrics (e.g., the interspersion/juxtaposition index) were calculated from the categorical canopy nitrogen maps and compared among fire and grazing treatments. Results showed that watersheds burned within one year had higher canopy nitrogen content and lower interspersions of high-nitrogen content patches than watersheds with longer fire intervals, suggesting an immediate and transient fire effect on grassland vegetation. In watersheds burned within one year, high-intensity grazing reduced vegetation density, but promoted grassland heterogeneity, as indicated by lower canopy nitrogen concentrations and greater interspersions of high-nitrogen content patches at the grazed sites than at the ungrazed sites. Variogram analyses across watersheds with different grazing histories showed that long-term bison grazing created greater spatial variability of canopy nitrogen than recent grazing by cattle. This comparison between bison and cattle is novel, as few field experiments have evaluated the role of grazing history in driving grassland heterogeneity. Our analyses extend previous research of effects from pyric herbivory on grassland heterogeneity by highlighting the role of grazing history in modulating the spatial and temporal distribution of aboveground nitrogen content in tallgrass prairie vegetation using a remote sensing approach. The comparison of canopy nitrogen properties and the variogram analysis of canopy nitrogen distribution provided by our study are useful for further mapping grassland canopy features and modeling grassland dynamics involving interplays among fire, large grazers, and vegetation communities.

Role of high nitrogen flux in InAlN growth by plasma-assisted molecular beam epitaxy

2020 ◽  
Vol 544 ◽  
pp. 125720
Author(s):  
Marta Sawicka ◽  
Natalia Fiuczek ◽  
Paweł Wolny ◽  
Anna Feduniewicz-Żmuda ◽  
Marcin Siekacz ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
High Nitrogen ◽  
Nitrogen Flux

Role of alkyl silatranes as plant growth regulators: comparative substitution effect on root and shoot development of wheat and maize

2018 ◽  
Vol 98 (13) ◽  
pp. 5129-5133
Author(s):  
Gurjaspreet Singh ◽  
Geetika Sharma ◽  
Sanchita ◽  
Pooja Kalra ◽  
Daizy R Batish ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Substitution Effect ◽  
Shoot Development

Occurrence of the Unusual Amino Compound S-Methyl Cysteine in Australian Members of the Restionaceae - Biological and Taxonomic Significance

1995 ◽  
Vol 43 (1) ◽  
pp. 73 ◽  
Author(s):  
JS Pate ◽  
E Rasins ◽  
PP Thumfort ◽  
CJ Mcchesney ◽  
KA Meney
Keyword(s):  
New Genus ◽  
Xylem Sap ◽  
Amino Compound ◽  
Taxonomic Significance ◽  
Protein Amino Acid ◽  
Total N ◽  
Australian Species ◽  
Ethanolic Extracts ◽  
Taxonomic Implications

The non-protein amino acid S-methyl cysteine (CH3-S-CH2> CH (NH2) COOH) was identified and assayed by HPLC and GC/MS analyses of ethanolic extracts of freshly-collected culms and rhizomes of Australian species of Restionaceae. Of 140 species examined, only 20 proved positive and two probably positive for the compound. Amounts in culms and rhizomes of these positive species varied from a trace to 74% of the ninhydrin-positive soluble amino N or from a trace to 33 mu mol per g fwt of tissue. Certain species showed substantial Variations in amounts of S-methyl cysteine between sites and seasons. Xylem bleeding sap was collected and analysed from 32 species. The nine species whose xylem sap was positive for S-methyl cysteine (0.5-23.5% of xylem total amino N) also rated positive in culms and rhizomes. Investment of N in S-methyl cysteine ranged from 0.1 to 6.3% of culm total N or 0.2-6.7% of rhizome total N. A possible role of the compound in protection against herbivory was examined. Positive species came from only three of the 19 currently recognized genera, Lepyrodia (16 positive, two possibly positive), Restio (one positive species) Loxocarya, (one positive species) and a further three as yet unnamed species. Under a proposed revision (B. Briggs and L. Johnson, pers. comm.), the positive species of Restio and the three unnamed species would be ascribed to a redefined genus (Loxocarya sens. orig.), thus restricting all species containing S-methyl cysteine to this new genus and Lepyrodia. The latter genus is changed under the proposed classification by transfer of certain species to the genus Sporadanthus. All six species proposed for such transfer lack the compound. Taxonomic implications of the findings are discussed.

scholarly journals Virus Accumulation and Whitefly Performance Modulate the Role of Alternate Host Species as Inoculum Sources of Tomato Yellow Leaf Curl Virus

Plant Disease ◽  
2020 ◽  
Vol 104 (11) ◽  
pp. 2958-2966
Author(s):  
Saioa Legarrea ◽  
Apurba Barman ◽  
Stanley Diffie ◽  
Rajagopalbabu Srinivasan
Keyword(s):  
Plant Species ◽  
Tomato Yellow Leaf ◽  
Palmer Amaranth ◽  
Insect Vector ◽  
Yellow Leaf ◽  
Alternate Host ◽  
Inoculum Sources ◽  
Leaf Curl Virus ◽  
Leaf Curl

Evaluating alternate hosts that facilitate the persistence of a virus in the landscape is key to understanding virus epidemics. In this study, we explored the role of several plant species (eggplant, pepper, and Palmer amaranth) as inoculum sources of tomato yellow leaf curl virus (TYLCV) and as reservoirs for its insect vector, Bemisia tabaci (Gennadius). All inoculated species were infected with TYLCV, but whiteflies acquired fewer viral copies via feeding from pepper and eggplant than from tomato and Palmer amaranth. Further, back-transmission assays to recipient tomato resulted in TYLCV infection only when TYLCV was acquired from Palmer amaranth or tomato. Analysis suggested that the role of plant species as TYLCV inoculum sources may be determined by the accumulation of viral copies in the plant, and consequently in the insect vector. In addition, results showed that all three alternate species could sustain populations of B. tabaci, while differentially influencing fitness of whiteflies. Eggplant was a superior host for whiteflies, whereas whitefly survival was compromised on pepper. Together, we demonstrate that both plant-virus and plant-vector interactions could influence the role of an alternate host in TYLCV epidemics, and in our region of study we highlight the potential risk of hosts such as Palmer amaranth in the spread of TYLCV.

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