Insights into the functional relationship between cytokinin-induced root system phenotypes and nitrate uptake in Brassica napus

2017 ◽  
Vol 44 (8) ◽  
pp. 832 ◽  
Author(s):  
Qianqian Guo ◽  
Jonathan Love ◽  
Jiancheng Song ◽  
Jessica Roche ◽  
Matthew H. Turnbull ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Root System ◽  
Culture Media ◽  
Root Traits ◽  
Spatial Arrangement ◽  
Shoot Biomass ◽  
N Availability ◽  
Root Proliferation ◽  
Brassica Napus L ◽  
15N Uptake

Root system architecture is the spatial arrangement of roots that impacts the capacity of plants to access nutrients and water. We employed pharmacologically generated morphological and molecular phenotypes and used in situ 15N isotope labelling, to investigate whether contrasting root traits are of functional interest in relation to nitrate acquisition. Brassica napus L. were grown in solidified phytogel culture media containing 1 mM KNO3 and treated with the cytokinin, 6-benzylaminopurine, the cytokinin antagonist, PI-55, or both in combination. The pharmacological treatments inhibited root elongation relative to the control. The contrasting root traits induced by PI-55 and 6-benzylaminopurine were strongly related to 15N uptake rate. Large root proliferation led to greater 15N cumulative uptake rather than greater 15N uptake efficiency per unit root length, due to a systemic response in the plant. This relationship was associated with changes in C and N resource distribution between the shoot and root, and in expression of BnNRT2.1, a nitrate transporter. The root : shoot biomass ratio was positively correlated with 15N cumulative uptake, suggesting the functional utility of root investment for nutrient acquisition. These results demonstrate that root proliferation in response to external nitrate is a behaviour which integrates local N availability and the systemic N status of the plant.

scholarly journals Morphological and Physiological Root Traits and Their Relationship with Nitrogen Uptake in Wheat Varieties Released from 1915 to 2013

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1149
Author(s):  
Guglielmo Puccio ◽  
Rosolino Ingraffia ◽  
Dario Giambalvo ◽  
Gaetano Amato ◽  
Alfonso S. Frenda
Keyword(s):  
Durum Wheat ◽  
Root System ◽  
N Uptake ◽  
Specific Root Length ◽  
Root Traits ◽  
Wheat Breeding ◽  
N Availability ◽  
Wheat Varieties ◽  
Uptake Efficiency ◽  
Positive Effects

Identifying genotypes with a greater ability to absorb nitrogen (N) may be important to reducing N loss in the environment and improving the sustainability of agricultural systems. This study extends the knowledge of variability among wheat genotypes in terms of morphological or physiological root traits, N uptake under conditions of low soil N availability, and in the amount and rapidity of the use of N supplied with fertilizer. Nine genotypes of durum wheat were chosen for their different morpho-phenological characteristics and year of their release. The isotopic tracer 15N was used to measure the fertilizer N uptake efficiency. The results show that durum wheat breeding did not have univocal effects on the characteristics of the root system (weight, length, specific root length, etc.) or N uptake capacity. The differences in N uptake among the studied genotypes when grown in conditions of low N availability appear to be related more to differences in uptake efficiency per unit of weight and length of the root system than to differences in the morphological root traits. The differences among the genotypes in the speed and the ability to take advantage of the greater N availability, determined by N fertilization, appear to a certain extent to be related to the development of the root system and the photosynthesizing area. This study highlights some variability within the species in terms of the development, distribution, and efficiency of the root system, which suggests that there may be sufficient grounds for improving these traits with positive effects in terms of adaptability to difficult environments and resilience to climate change.

scholarly journals Two Wheat Cultivars with Contrasting Post-Embryonic Root Biomass Differ in Shoot Re-Growth after Defoliation: Implications for Breeding Grazing Resilient Forages

Plants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 470
Author(s):  
Paez-Garcia ◽  
Liao ◽  
Blancaflor
Keyword(s):  
Winter Wheat ◽  
Root Growth ◽  
Root System ◽  
Aboveground Biomass ◽  
Root Traits ◽  
Shoot Biomass ◽  
Wheat Cultivars ◽  
Leaf Clipping ◽  
The Impact ◽  
Embryonic Root

The ability of forages to quickly resume aboveground growth after grazing is a trait that enables farmers to better manage their livestock for maximum profitability. Leaf removal impairs root growth. As a consequence of a deficient root system, shoot re-growth is inhibited leading to poor pasture performance. Despite the importance of roots for forage productivity, they have not been considered as breeding targets for improving grazing resilience due in large part to the lack of knowledge on the relationship between roots and aboveground biomass re-growth. Winter wheat (Triticum aestivum) is extensively used as forage source in temperate climates worldwide. Here, we investigated the impact of leaf clipping on specific root traits, and how these influence shoot re-growth in two winter wheat cultivars (i.e., Duster and Cheyenne) with contrasting root and shoot biomass. We found that root growth angle and post-embryonic root growth in both cultivars are strongly influenced by defoliation. We discovered that Duster, which had less post-embryonic roots before defoliation, reestablished its root system faster after leaf cutting compared with Cheyenne, which had a more extensive pre-defoliation post-embryonic root system. Rapid resumption of root growth in Duster after leaf clipping was associated with faster aboveground biomass re-growth even after shoot overcutting. Taken together, our results suggest that lower investments in the production of post-embryonic roots presents an important ideotype to consider when breeding for shoot re-growth vigor in dual purpose wheat.

scholarly journals Assessment of the Capacity of Beneficial Bacterial Inoculants to Enhance Canola (Brassica napus L.) Growth under Low Water Activity

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1449
Author(s):  
Dasun Premachandra ◽  
Lee Hudek ◽  
Aydin Enez ◽  
Ross Ballard ◽  
Steve Barnett ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Plant Growth ◽  
Water Activity ◽  
Production Costs ◽  
Annual Rainfall ◽  
Shoot Biomass ◽  
Brassica Napus L ◽  
Environmentally Sustainable ◽  
Plant Growth Promoting ◽  
Growth Promoting

Canola (Brassica napus L.) is the third largest crop produced in Australia after wheat and barley. For such crops, the variability of water access, reduced long-term annual rainfall and increasing water prices, higher overall production costs, and variability in production quantity and quality are driving the exploration of new tools to maintain production in an economical and environmentally sustainable way. Microorganisms associated with the rhizosphere have been shown to enhance plant growth and offer a potential way to maintain or even increase crop production quality and yield in an environmentally sustainable way. Here, seven bacterial isolates from canola rhizosphere samples are shown to enhance canola growth, particularly in low water activity systems. The seven strains all possessed commonly described plant growth promoting traits, including the ability to produce indole-3-acetic acid and 1-aminocyclopropane-1-carboxylate deaminase, and the capacity to solubilise nutrients (Fe2+/3+ and PO43−). When the isolates were inoculated at the time of sowing in pot-based systems with either sand or clay loam media, and in field trials, a significant increase in dry root and shoot biomass was recorded compared to uninoculated controls. It is likely that the strains’ plant growth promoting capacity under water stress is due to the combined effects of the bacterial phenotypes examined here.

YIELD AND NITROGEN RECOVERY OF RAPE (BRASSICA NAPUS L.) IN RESPONSE TO APPLICATION OF LEGUMINOUS LEAF LITTER AND SUPPLEMENTAL INORGANIC NITROGEN

2015 ◽  
Vol 52 (4) ◽  
pp. 518-536 ◽  
Author(s):  
FIONA MUCHECHETI ◽  
IGNACIO C. MADAKADZE
Keyword(s):  
Brassica Napus ◽  
Leaf Litter ◽  
Inorganic Nitrogen ◽  
Calliandra Calothyrsus ◽  
N Recovery ◽  
Total Biomass ◽  
N Availability ◽  
Vegetable Production ◽  
Brassica Napus L ◽  
Mineral N

SUMMARYThe short term nutrient supply of Leucaena leucocephala, Calliandra calothyrsus, Acacia angustissima and Acacia karoo prunings with or without supplemental inorganic nitrogen were tested using rape (Brassica napus L.) in a field trial. Prunings were applied at a rate of 5 t ha−1 to soil, alone or with supplemental N at 37.5 kg N ha−1 (¼ of recommended N). The respective decomposition and N release constants of the prunings were 9.15 and 9.70% for L. leucocephala; 6.15 and 6.40 for A. angustissima; 4.50 and 4.90 for C. calothyrsus; and 2.20 and 2.10 for A. karoo. These constants were best described by the (lignin+polyphenol)-to-nitrogen ratio of the prunings. Total biomass over the two seasons ranged from 1.40 to 17.28 t DM ha−1 and total growth rates ranged from 2.34–26.70 g plant−1 week−1. The cumulative N recovery at week 9 ranged from 21.1–66.1 %. Legume tree leaves can be used as a source of N for vegetable production. Farmers who use high tannin leaf litter are recommended to supplement with mineral N in order to assure adequate N availability during plant growth.

scholarly journals Complete root specimen of plants grown in soil-filled root box: sampling, measuring, and staining method

Plant Methods ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Takuya Koyama ◽  
Shun Murakami ◽  
Toshihiko Karasawa ◽  
Masato Ejiri ◽  
Katsuhiro Shiono
Keyword(s):  
Root System ◽  
Surface Area ◽  
Visual Information ◽  
Physiological Function ◽  
Physiological Activity ◽  
Root Traits ◽  
Arbuscular Mycorrhizal ◽  
Spatial Arrangement ◽  
Root Surface ◽  
Root Surface Area

Abstract Background Detailed datasets containing root system and its architecture in soil are required to improve understanding of resource capture by roots. However, most of the root study methods have paid little attention to make and preserve whole root specimens. This study introduces root system sampling equipment that makes the entire root specimen with minimum impairment and without displacement of the spatial arrangement of the root system in root boxes. The objectives are to assess: whether the equipment can rapidly sample the entire root system; whether root surface area is measurable from a scanned digital image of the root specimen; and whether staining of the entire root specimens would provide multidimensional visual information on the interaction between soil and physiological function of root system architecture (RSA). For validation, we examined the root response of two soybean cultivars to arbuscular mycorrhizal (AM) inoculation and the effect of waterlogging stress on the physiological activity of buckwheat RSA. Results The root boxes allowed soybean and buckwheat plants to grow uniformly across the replications. Both species showed significant differences between cultivars and/or among treatments in shoot and root traits. The equipment enabled to sample the whole-root specimens of soybean and buckwheat, where the tips of the fine roots were alive (diameter < 0.2 mm). Also, the whole root specimens of soybean were made in about 7 min. The root surface area calculated from the scanned soybean specimens showed a significant correlation with that calculated from the roots spread out in water (a common method). Staining of the soybean root specimens enabled us to observe the localized root proliferation induced by AM colonization. Moreover, staining of the buckwheat root specimens made it possible to examine the respiratory activity of each root at different depths. Conclusions The present method realized: fast and accurate production of the whole root specimen and precise calculation of the specimens’ root surface area. Moreover, staining of the root specimens enabled analyzing the interaction between soil and physiological function of RSA. The evaluation of root traits, using our methods, will contribute to developing agronomic management and breeding program for sustainable food production.

Autotoxicity in isolated microspore cultures of Brassica napus

1988 ◽  
Vol 66 (8) ◽  
pp. 1665-1670 ◽  
Author(s):  
L. S. Kott ◽  
L. Polsoni ◽  
B. Ellis ◽  
W. D. Beversdorf
Keyword(s):  
Brassica Napus ◽  
Embryo Development ◽  
Oilseed Rape ◽  
Culture Media ◽  
High Density ◽  
Normal Embryo ◽  
Embryo Morphology ◽  
Negative Effects ◽  
Embryogenic Cultures ◽  
Brassica Napus L

Effects of a suspected toxin in isolated microspore cultures of oilseed rape, Brassica napus L., were observed in the reduced levels of embryogenesis and in altered embryo morphology. The toxin appeared to be generated by the cultured spores themselves. Inclusion of binucleate microspores in the cultures, along with younger, potentially embryogenic spores, was correlated with these negative effects and could be simulated by inoculation of embryogenic cultures with media generated from high-density cultures of older spores. Replacement of culture media 24 h after microspore isolation effectively reduced the levels of the autotoxins in the medium and allowed normal embryo development.

scholarly journals Reorganization of Protein Tyrosine Nitration Pattern Indicates the Relative Tolerance of Brassica napus (L.) over Helianthus annuus (L.) to Combined Heavy Metal Treatment

Plants ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 902
Author(s):  
Gábor Feigl ◽  
Ádám Czifra ◽  
Árpád Molnár ◽  
Attila Bodor ◽  
Etelka Kovács ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Root System ◽  
Helianthus Annuus ◽  
Municipal Sewage ◽  
Oxide Content ◽  
Tyrosine Nitration ◽  
Brassica Napus L ◽  
Protein Tyrosine ◽  
Protein Tyrosine Nitration ◽  
Helianthus Annuus L

Metal-polluted areas, especially where municipal sewage is used as fertilizer, often have high concentrations of more than one metal. The development of the root system is regulated by a complex signaling network, which includes reactive oxygen and nitrogen species. The delicate balance of the endogenous signal system can be affected by various environmental stimuli including heavy metals (HMs) in excess. Our goal was to analyze the microelement homeostasis, root architecture, and to determine the underlying changes in the nitro-oxidative status in the root system of rapeseed (Brassica napus L.) and sunflower (Helianthus annuus L.) subjected to combined HM treatments. The effect of model-sewage in two different layouts was simulated in rhizotron system by only supplementing the highest HM concentrations (Cd, Cr, Cu, Hg, Ni, Pb, and Zn) legally allowed. The two species reacted differently to combined HM treatment; compared to the relatively sensitive sunflower, rapeseed showed better metal translocation capability and root growth even at the more severe treatment, where the pattern of protein tyrosine nitration was reorganized. The obtained results, especially the increased nitric oxide content and changed pattern of tyrosine nitration in rapeseed, can indicate acclimation and species-specific nitro-oxidative responses to combined HM stress.

Genetic Analysis on Flowering Time and Root System in Brassica napus L

Crop Science ◽  
2013 ◽  
Vol 53 (1) ◽  
pp. 141-147 ◽  
Author(s):  
Mukhlesur Rahman ◽  
Phillip McClean
Keyword(s):  
Brassica Napus ◽  
Genetic Analysis ◽  
Root System ◽  
Flowering Time ◽  
Brassica Napus L

scholarly journals Anchorage Mechanics of the Tap Root System of Winter-sown Oilseed Rape (Brassica napus L.)

2001 ◽  
Vol 87 (3) ◽  
pp. 397-404 ◽  
Author(s):  
A Goodman
Keyword(s):  
Brassica Napus ◽  
Root System ◽  
Oilseed Rape ◽  
Brassica Napus L ◽  
Tap Root

scholarly journals Shovelomics root traits assessed on the EURoot maize panel are highly heritable across environments but show low genotype-by-nitrogen interaction

Euphytica ◽  
2019 ◽  
Vol 215 (10) ◽  
Author(s):  
Chantal A. Le Marié ◽  
Larry M. York ◽  
Alexandre Strigens ◽  
Marcos Malosetti ◽  
Karl-Heinz Camp ◽  
...  
Keyword(s):  
Root System ◽  
Root Traits ◽  
N Fertilization ◽  
N Availability ◽  
Stay Green ◽  
N Application ◽  
Growth Environment ◽  
Root Stock ◽  
Horizontal Expansion ◽  
The Impact

Abstract The need for sustainable intensification of agriculture in the coming decades requires a reduction in nitrogen (N) fertilization. One opportunity to reduce N application rates without major losses in yield is breeding for nutrient efficient crops. A key parameter that influences nutrient uptake efficiency is the root system architecture (RSA). To explore the impact of N availability on RSA and to investigate the impact of the growth environment, a diverse set of 36 inbred dent maize lines crossed to the inbred flint line UH007 as a tester was evaluated for N-response over 2 years on three different sites. RSA was investigated by excavating and imaging of the root crowns followed by image analysis with REST software. Despite strong site and year effects, trait heritability was generally high. Root traits showing the greatest heritability (> 0.7) were the width of the root stock, indicative of the horizontal expansion, and the fill factor, a measure of the density of the root system. Heritabilities were in a similar range under high or low N application. Under N deficiency the root stock size decreased, the horizontal expansion decreased and the root stock became less dense. However, there was little differential response of the genotypes to low N availability. Thus, the assessed root traits were more constitutively expressed rather than showing genotype-specific plasticity to low N. In contrast, strong differences were observed for ‘stay green’ and silage yield, indicating that these highly heritable traits are good indicators for responsiveness to low N.

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