EcoMeristem, a model of morphogenesis and competition among sinks in rice. 2. Simulating genotype responses to phosphorus deficiency

2006 ◽  
Vol 33 (4) ◽  
pp. 325 ◽  
Author(s):  
Michael Dingkuhn ◽  
Delphine Luquet ◽  
HaeKoo Kim ◽  
Ludovic Tambour ◽  
Anne Clement-Vidal
Keyword(s):  
Phenotypic Plasticity ◽  
Root Growth ◽  
Phosphorus Deficiency ◽  
Functional Model ◽  
Weight Ratio ◽  
Growth Stimulation ◽  
P Deficiency ◽  
Physiological Feedback ◽  
Controlled Environments ◽  
Shoot Weight

Phenotypic plasticity enables plants to adjust their morphology and phenology to variable environments. Although potentially important for crop breeding and management, the physiology and genetics of plasticity traits are poorly understood, and few models exist for their study. In the previous paper of this series, the structural–functional model EcoMeristem was described and field validated for vegetative-stage rice. This study applies the model to an experimental study on phosphorus deficiency effects on two morphologically contrasting rice cultivars, IR64 and Azucena, grown in controlled environments under hydroponics culture. Phosphorus deficiency caused severe biomass growth reductions in the shoot but not in the root, thus increasing the root / shoot weight ratio. It also inhibited tiller formation and leaf elongation, prolonged the phyllochron, and increased carbohydrate reserve pools in the plant. Analysis aided by the model identified inhibition of leaf extension and tillering as primary effects of the stress. Physiological feedback probably led to longer phyllochron, greater reserve accumulation and root growth stimulation. The main effect of P deficiency appeared to be a reduction in demand for assimilates in the shoot while photosynthetic radiation use efficiency remained nearly constant, resulting in spill-over of excess assimilates into reserve compartments and root growth. The results are discussed in the light of future applications of EcoMeristem for phenotyping and genetic analyses of phenotypic plasticity.

scholarly journals Fertilizer, Irrigation and Root Ball Slicing Affects Burford Holly Growth after Planting

1996 ◽  
Vol 14 (3) ◽  
pp. 105-110 ◽  
Author(s):  
Edward F. Gilman ◽  
Thomas H. Yeager ◽  
Diane Weigle
Keyword(s):  
Root Growth ◽  
Weight Ratio ◽  
Dry Weight ◽  
Total Weight ◽  
Root Weight ◽  
Irrigation Frequency ◽  
Shoot Dry Weight ◽  
Shoot Number ◽  
Ilex Cornuta ◽  
Shoot Weight

Abstract Dwarf burford holly (Ilex cornuta ‘Burfordii Nana’) fertilized with 22.1 g N/container/yr of nitrogen during production in the nursery generated more new shoot weight but less root weight after transplanting to a landscape than those receiving 14.8 g N/container/yr. Slicing the root ball at planting, compared to not slicing, resulted in comparable regenerated root weight but reduced new shoot number, new shoot dry weight and new shoot:regenerated root dry weight ratio when irrigation was not applied daily after transplanting. Although irrigation frequency did not impact total weight of regenerated roots into landscape soil, more roots grew from the bottom half of the root ball when plants were irrigated periodically after planting than when plants received daily irrigation. Plants irrigated other than daily produced fewer shoots and less shoot weight than those receiving irrigation daily after transplanting. When plants were without irrigation for 4 or 6 days in the first week after transplanting, those planted without the nursery container on the root ball were more stressed (more negative xylem potential) than those planted with the container still on the root ball. However, two weeks later, plants without the nursery container were less stressed due to root growth into landscape soil.

Effect of Undercutting on Loblolly Pine Seedling Size and Its Relation to Root Growth Potential

1986 ◽  
Vol 10 (1) ◽  
pp. 24-27 ◽  
Author(s):  
Peter P. Feret ◽  
Richard E. Kreh
Keyword(s):  
Root Growth ◽  
Loblolly Pine ◽  
Weight Ratio ◽  
Growth Potential ◽  
Shoot Biomass ◽  
Root Weight ◽  
Root Growth Potential ◽  
Seedling Size ◽  
Seedling Physiology ◽  
Shoot Weight

Abstract Loblolly pine seedlings undercut using five different treatments extending from July to September exhibited significant alteration of shoot and root biomass. Root growth potential (RGP) (measured by number of new elongating roots) was not significantly altered by undercutting. Undercutting did significantly alter the RGP/root weight ratio and the RGP/shoot weight ratio because of both concomitant changes in root and shoot biomass and changes in seedling physiology. Root growth potential and efficiency of existing old roots to produce new roots were not well correlated with seedling size.

scholarly journals Fertilizer, Irrigation, and Root Ball Slicing Affects Shrub Growth after Planting

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 605e-605
Author(s):  
Edward F. Gilman ◽  
Thomas H. Yeager ◽  
Diane Weigle
Keyword(s):  
Root Growth ◽  
Weight Ratio ◽  
Dry Weight ◽  
Total Weight ◽  
Root Weight ◽  
Irrigation Frequency ◽  
Shoot Dry Weight ◽  
Shoot Number ◽  
Ilex Cornuta ◽  
Shoot Weight

Dwarf burford holly (Ilex cornuta `Burfordii Nana') fertilized with N at 22.1 g per container yearly during production in the nursery generated more new shoot weight but less root weight after transplanting to a landscape than those receiving N at 14.8 g per container yearly. Slicing the root ball at planting, compared to not slicing, resulted in comparable regenerated root weight but reduced new shoot number, new shoot dry weight, and new shoot:regenerated root dry-weight ratio when irrigation was not applied daily after transplanting. Although irrigation frequency did not impact total weight of regenerated roots into landscape soil, more roots grew from the bottom half of the root ball when plants were irrigated periodically after planting than when plants received daily irrigation. Plants irrigated other than daily produced fewer shoots and less shoot weight than those receiving irrigation daily after transplanting. When plants were without irrigation for 4 or 6 days in the first week after transplanting, those planted without the nursery container on the root ball were more stressed (more negative xylem potential) than those planted with the container still on the root ball. However, 2 weeks later, plants without the nursery container were less stressed due to root growth into landscape soil.

scholarly journals Physiological responses and transcriptomic changes reveal the mechanisms underlying adaptation of Stylosanthes guianensis to phosphorus deficiency

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Zhijian Chen ◽  
Jianling Song ◽  
Xinyong Li ◽  
Jacobo Arango ◽  
Juan Andres Cardoso ◽  
...  
Keyword(s):  
Root Growth ◽  
Phosphorus Deficiency ◽  
Utilization Efficiency ◽  
Differentially Expressed ◽  
Purple Acid Phosphatase ◽  
Growth And Yield ◽  
P Deficiency ◽  
Stylosanthes Guianensis ◽  
Pi Homeostasis ◽  
Pi Starvation

Abstract Background Phosphorus (P) is an essential macronutrient for plant growth that participates in a series of biological processes. Thus, P deficiency limits crop growth and yield. Although Stylosanthes guianensis (stylo) is an important tropical legume that displays adaptation to low phosphate (Pi) availability, its adaptive mechanisms remain largely unknown. Results In this study, differences in low-P stress tolerance were investigated using two stylo cultivars (‘RY2’ and ‘RY5’) that were grown in hydroponics. Results showed that cultivar RY2 was better adapted to Pi starvation than RY5, as reflected by lower values of relative decrease rates of growth parameters than RY5 at low-P stress, especially for the reduction of shoot and root dry weight. Furthermore, RY2 exhibited higher P acquisition efficiency than RY5 under the same P treatment, although P utilization efficiency was similar between the two cultivars. In addition, better root growth performance and higher leaf and root APase activities were observed with RY2 compared to RY5. Subsequent RNA-seq analysis revealed 8,348 genes that were differentially expressed under P deficient and sufficient conditions in RY2 roots, with many Pi starvation regulated genes associated with P metabolic process, protein modification process, transport and other metabolic processes. A group of differentially expressed genes (DEGs) involved in Pi uptake and Pi homeostasis were identified, such as genes encoding Pi transporter (PT), purple acid phosphatase (PAP), and multidrug and toxin extrusion (MATE). Furthermore, a variety of genes related to transcription factors and regulators involved in Pi signaling, including genes belonging to the PHOSPHATE STARVATION RESPONSE 1-like (PHR1), WRKY and the SYG1/PHO81/XPR1 (SPX) domain, were also regulated by P deficiency in stylo roots. Conclusions This study reveals the possible mechanisms underlying the adaptation of stylo to P deficiency. The low-P tolerance in stylo is probably manifested through regulation of root growth, Pi acquisition and cellular Pi homeostasis as well as Pi signaling pathway. The identified genes involved in low-P tolerance can be potentially used to design the breeding strategy for developing P-efficient stylo cultivars to grow on acid soils in the tropics.

scholarly journals Roles of Phosphate Solubilizing Microorganisms from Managing Soil Phosphorus Deficiency to Mediating Biogeochemical P Cycle

Biology ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 158
Author(s):  
Jiang Tian ◽  
Fei Ge ◽  
Dayi Zhang ◽  
Songqiang Deng ◽  
Xingwang Liu
Keyword(s):  
Phosphorus Deficiency ◽  
Soil Phosphorus ◽  
Biological Molecules ◽  
P Deficiency ◽  
Soil P ◽  
Soil Systems ◽  
Intensively Managed ◽  
Phosphate Solubilizing ◽  
P Fertilizers ◽  
P Cycle

Phosphorus (P) is a vital element in biological molecules, and one of the main limiting elements for biomass production as plant-available P represents only a small fraction of total soil P. Increasing global food demand and modern agricultural consumption of P fertilizers could lead to excessive inputs of inorganic P in intensively managed croplands, consequently rising P losses and ongoing eutrophication of surface waters. Despite phosphate solubilizing microorganisms (PSMs) are widely accepted as eco-friendly P fertilizers for increasing agricultural productivity, a comprehensive and deeper understanding of the role of PSMs in P geochemical processes for managing P deficiency has received inadequate attention. In this review, we summarize the basic P forms and their geochemical and biological cycles in soil systems, how PSMs mediate soil P biogeochemical cycles, and the metabolic and enzymatic mechanisms behind these processes. We also highlight the important roles of PSMs in the biogeochemical P cycle and provide perspectives on several environmental issues to prioritize in future PSM applications.

Dynamics of root growth stimulation in Nicotiana tabacum in increasing light intensity

2006 ◽  
Vol 29 (10) ◽  
pp. 1936-1945 ◽  
Author(s):  
KERSTIN A. NAGEL ◽  
ULRICH SCHURR ◽  
ACHIM WALTER
Keyword(s):  
Nicotiana Tabacum ◽  
Light Intensity ◽  
Root Growth ◽  
Growth Stimulation

Assessment of tolerance for reducing yield losses in field pea caused by Aphanomyces root rot

2013 ◽  
Vol 93 (3) ◽  
pp. 473-482 ◽  
Author(s):  
R. L. Conner ◽  
K. F. Chang ◽  
S. F. Hwang ◽  
T. D. Warkentin ◽  
K. B. McRae
Keyword(s):  
Disease Severity ◽  
Root Rot ◽  
Weight Ratio ◽  
Field Pea ◽  
Control Measures ◽  
Effective Control ◽  
Yield Losses ◽  
Plant Vigour ◽  
Shoot Weight ◽  
High Yields

Conner, R. L., Chang, K. F., Hwang, S. F., Warkentin, T. D. and McRae, K. B. 2013. Assessment of tolerance for reducing yield losses in field pea caused by Aphanomyces root rot. Can. J. Plant Sci. 93: 473–482. Aphanomyces root rot, caused by Aphanomyces euteiches Drechs., is a serious disease of peas (Pisum sativum) that can severely reduce seed yield, and few effective control measures are available. The development of pea cultivars with tolerance or partial resistance to Aphanomyces root rot is generally considered to be one of the best options to reduce yield loss. A 4-yr field study was conducted at disease-free sites and at an Aphanomyces root rot site to compare the responses of cultivars and lines in the presence and absence of Aphanomyces root rot, identify breeding lines with tolerance and to evaluate the effects of tolerance on plant growth, disease severity and yield. At the Aphanomyces root rot site, a second test was established in which the phosphite fungicide Phostrol™ was applied as a soil drench treatment to the pea cultivars and lines. Aphanomyces root rot reduced seedling emergence, biomass production and yield in the susceptible pea genotypes. However, line 00-2067 consistently produced relatively high yields at all the field sites. At the Aphanomyces root rot site, yield was closely associated with plant vigour and shoot weight. Small, but significant, differences (P<0.05) in disease severity were observed between susceptible cultivars and tolerant lines indicating that the lines producing high yields at the Aphanomyces root rot site are tolerant rather than partially resistant. The root/shoot weight ratio was very low in the tolerant lines, indicating that even though their root systems were reduced and severely damaged by root rot, they were still able to produce high yields under favourable conditions for the disease. Drench application of the fungicide Phostrol™ did not significantly reduce root rot severity or improve the performance of any of the pea cultivars or lines.

Accelerating growth of silver fir seedlings under controlled environments

1987 ◽  
Vol 17 (8) ◽  
pp. 835-839
Author(s):  
Sunil Puri ◽  
M. A. Tak
Keyword(s):  
Positive Response ◽  
Maximum Growth ◽  
Day Length ◽  
Silver Fir ◽  
N Application ◽  
Nitrogen Levels ◽  
Shoot Ratio ◽  
Percent Increase ◽  
Controlled Environments ◽  
Shoot Weight

Studies on Abiespindrow seedlings were conducted to accelerate and attain maximum growth under controlled environmental conditions. Seedlings of age 7, 19, and 31 months collected from Manali, Shilaru, and Kashmir provenances were treated for 90 days with four photoperiods (natural day length and 12, 18, and 24 h light) and two nitrogen levels (1.0 and 1.5 g/seedling). A positive response to light and N application was observed. Initially, light had no effect on roots (up to 45 days) but later on a significant increase in length and weight of roots was observed. Root to shoot ratio decreased with light but increased with N applied to seedlings. The interaction among photoperiod, N, provenance, and age, calculated from analysis of variance, was significant for root length and root and shoot weight at 45 and 90 days. The maximum percent increase in growth and biomass was observed in the 1-0 age from the Kashmir provenance.

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

Plants ◽  
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.

scholarly journals Overexpression of OsPIN2 Regulates Root Growth and Formation in Response to Phosphate Deficiency in Rice

2019 ◽  
Vol 20 (20) ◽  
pp. 5144
Author(s):  
Huwei Sun ◽  
Xiaoli Guo ◽  
Fugui Xu ◽  
Daxia Wu ◽  
Xuhong Zhang ◽  
...  
Keyword(s):  
Root Growth ◽  
Growth And Development ◽  
Plant Root ◽  
Lateral Roots ◽  
Root Hairs ◽  
Phosphate Deficiency ◽  
P Deficiency ◽  
Auxin Distribution ◽  
Seminal Roots ◽  
Underlying Mechanisms

The response of root architecture to phosphate (P) deficiency is critical in plant growth and development. Auxin is a key regulator of plant root growth in response to P deficiency, but the underlying mechanisms are unclear. In this study, phenotypic and genetic analyses were undertaken to explore the role of OsPIN2, an auxin efflux transporter, in regulating the growth and development of rice roots under normal nutrition condition (control) and low-phosphate condition (LP). Higher expression of OsPIN2 was observed in rice plants under LP compared to the control. Meanwhile, the auxin levels of roots were increased under LP relative to control condition in wild-type (WT) plants. Compared to WT plants, two overexpression (OE) lines had higher auxin levels in the roots under control and LP. LP led to increased seminal roots (SRs) length and the root hairs (RHs) density, but decreased lateral roots (LRs) density in WT plants. However, overexpression of OsPIN2 caused a loss of sensitivity in the root response to P deficiency. The OE lines had a shorter SR length, lower LR density, and greater RH density than WT plants under control. However, the LR and RH densities in the OE lines were similar to those in WT plants under LP. Compared to WT plants, overexpression of OsPIN2 had a shorter root length through decreased root cell elongation under control and LP. Surprisingly, overexpression of OsPIN2 might increase auxin distribution in epidermis of root, resulting in greater RH formation but less LR development in OE plants than in WT plants in the control condition but levels similar of these under LP. These results suggest that higher OsPIN2 expression regulates rice root growth and development maybe by changing auxin distribution in roots under LP condition.

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