The role of calcium in alleviating aluminium toxicity

1986 ◽  
Vol 37 (4) ◽  
pp. 375 ◽  
Author(s):  
AK Alva ◽  
CJ Asher ◽  
DG Edwards
Keyword(s):  
Ionic Strength ◽  
Root Growth ◽  
Root Length ◽  
Protective Action ◽  
Primary Root ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Aluminium Toxicity ◽  
Solution Ionic Strength ◽  
Soybean Root

Effects of varying calcium (Ca) concentration at constant or varying solution ionic strength on root elongation of soybean (Glycine max (L.) Merr.) and subterranean clover (Trifolium subterraneum L.) were determined in aluminium (Al) free nutrient solution or solutions containing monomeric Al activities (+aAl mono) of 8-10 8M for subterranean clover and 20-22 8M for soybean. In Al-free solutions, the root length for subterranean clover was not significantly influenced by Ca or ionic strength. However, soybean root length was greater at 500 8M Ca than at higher Ca concentrations. Raising the ionic strength at 500 and 5000 8M Ca significantly decreased root length. In the presence of Al, maximum root length of both species occurred at 15 000 8M Ca. Soybean root length at 500 and 5000 8M Ca was 35% and 87% respectively of that at 15000 8M Ca. The corresponding values for subterranean clover were 53% and 81%. The positive effect of Ca concentration on root length, despite a nearly constant +aAL mono, confirms the existence of a protective action of Ca against Al toxicity. Raising the solution ionic strength at 500 8M Ca in the presence of Al improved the root growth of soybean by 86% and that of subterranean clover by 45%. At 5000 8M Ca, a small beneficial effect of increased ionic strength (14%) was found only in subterranean clover. Increasing Ca concentration in solution decreased water extractable and 0-1 M HNO3 extractable Al in roots of both plant species. Transfer of soybean seedlings to Al-free nutrient solutions containing 500, 1500 or 5000 pM Ca after 24, 48 or 96 h in a solution containing +aAL mono of 22 8M resulted in a substantial recovery in primary root growth. Relative root lengths were in each case significantly higher at 5000 8M Ca than at 1500 or 500 pM Ca. Roots transferred to 500 8M Ca after exposure to Al for 6 or 18 h underwent a period of accelerated elongation after a lag period of 30-40 h. By 138 h there were no significant differences in root length between the unstressed control plants and those subjected to 6 or 18 h Al-stress.

Copper nutrition of subterranean clover (Trifolium subterraneum L. cv. Seaton Park). I. Effects of copper supply on growth and development

1981 ◽  
Vol 32 (2) ◽  
pp. 257 ◽  
Author(s):  
DJ Reuter ◽  
AD Robson ◽  
JF Loneragan ◽  
DJ Tranthim-Fryer
Keyword(s):  
Root Growth ◽  
Growth And Development ◽  
Copper Deficiency ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dry Weight ◽  
Growing Season ◽  
Internode Elongation ◽  
Plant Parts ◽  
Lateral Branches

Effects of severe and moderate copper deficiency on the development of leaves and lateral branches, on the distribution of dry weight within the plant, and on seed yield of Seaton Park subterranean clover were assessed as part of three glasshouse experiments. Copper deficiency markedly depressed top and root growth without producing any distinctive symptoms. It retarded phasic development by delaying development of leaves and lateral branches, senescence of plant parts, and flowering: it also depressed the proportion of stem plus petiole in plant tops and decreased internode elongation, pollen fertility and the number of burrs and seeds formed. As a result of its effect in delaying flowering, copper deficiency would depress seed production particularly strongly when low soil water supply shortens the growing season. The need for suitable procedures for diagnosing copper deficiency is emphasized by the lack of specific plant symptoms in this species.

Root distribution in space and time in Trifolium subterraneum

1985 ◽  
Vol 36 (4) ◽  
pp. 601 ◽  
Author(s):  
CJ Pearson ◽  
BC Jacobs
Keyword(s):  
Leaf Area ◽  
Root Length ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Coarse Sand ◽  
Horizontal Distribution ◽  
Dry Matter Partitioning ◽  
Rooting Zone ◽  
Root Death ◽  
Vertical And Horizontal Distribution

Distribution of length and weight of roots of subterranean clover cultivars Northarn and Nungarin were measured in the field throughout a growing season. Plants were grown at seven populations from 2 to 1510 plants per m2 in coarse sand which had a bulk density of 1.4 g cm-3. Root growth was described by its vertical and horizontal distribution as functions of population and time after emergence. Differences in growth between cultivars were small. Root depth, which reached a maximum (plateau) at about 90 days, did not vary with plant population. Root density (length per volume of soil) increased faster at high population due to a higher density of' roots beneath the mainstream and an attenuation with distance away from the mainstem which did not appear to be affected by population. Root densities were 10 cm cm-3 in the uppermost core (0-10 cm depth) and 1.6 -3.5 cm cm-3 throughout the rooting zone (0-50 cm) at 119 days after emergence. Root death, estimated from dichlorotrianzinyl staining, was negligible. Leaf area per plant declined with population above 16 plants per m2; leaf area per unit root length (in cores beneath the mainstream) declined 90-fold with increase in population. Top weight and burr yield per plant at final harvest also declined with increasing population; burr yield per m2 also fell significantly at the highest population. It is concluded that the amount of root per unit area increases with population and that plants appear to adjust conservatively in some respects (to much lower leaf area per root length) while being unable to sustain dry matter partitioning (reducing burr/top yields) at the highest population studied.

scholarly journals Mechanical touch responses of Arabidopsis TCH1-3 mutant roots on inclined hard-agar surface

2016 ◽  
Vol 30 (1) ◽  
pp. 105-111 ◽  
Author(s):  
Guodong Zha ◽  
Bochu Wang ◽  
Junyu Liu ◽  
Jie Yan ◽  
Liqing Zhu ◽  
...  
Keyword(s):  
Root Growth ◽  
Root Length ◽  
Lateral Root ◽  
Plant Root ◽  
Primary Root ◽  
Agar Plate ◽  
Touch Response ◽  
Agar Surface ◽  
Root Growth And Development ◽  
Touch Stimulus

Abstract The gravity-induced mechanical touch stimulus can affect plant root architecture. Mechanical touch responses of plant roots are an important aspect of plant root growth and development. Previous studies have reported that Arabidopsis TCH1-3 genes are involved in mechano-related events, how-ever, the physiological functions of TCH1-3 genes in Arabidopsis root mechanoresponses remain unclear. In the present study, we applied an inclined hard agar plate method to produce mechanical touch stimulus, and provided evidence that altered mechanical environment could influence root growth. Furthermore, tch1-3 Arabidopsis mutants were investigated on inclined agar surfaces to explore the functions of TCH1-3 genes on Arabidopsis root mechanoresponses. The results showed that two tch2 mutants, cml24-2 and cml24-4, exhibited significantly reduced root length, biased skewing, and decreased density of lateral root. In addition, primary root length and density of lateral root of tch3 (cml12-2) was significantly decreased on inclined agar surfaces. This study indicates that the tch2 and tch3 mutants are hypersensitive to mechanical touch stimulus, and TCH2 (CML24-2 and CML24-4) and TCH3 (CML12-2) genes may participate in the mechanical touch response of Arabidopsis roots.

Understanding subsoil acidification: effect of nitrogen transformation and nitrate leaching

Soil Research ◽  
2000 ◽  
Vol 38 (4) ◽  
pp. 837 ◽  
Author(s):  
Z. Rengel ◽  
C. Tang ◽  
C. Raphael ◽  
J. W. Bowden
Keyword(s):  
Soil Ph ◽  
Nitrate Leaching ◽  
Root Length ◽  
Root Length Density ◽  
Soil Column ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Nitrogen Transformation ◽  
Column Experiments ◽  
Excess Water

Nitrification and nitrate leaching have been suggested to be major causes of soil acidification. However, it is unknown whether these processes cause subsoil acidification. Soil column experiments examined the effect of the addition of Ca(NO3)2 or (NH4)2SO4 to the topsoil horizon on subsoil acidification under nodulated lupins (Lupinus angustifolius L.) and subterranean clover (Trifolium subterraneum L.). Nitrate leaching was achieved by adding excess water to the surface of the columns. Where basal nutrients were applied only to the top 10-cm layer, about 60–70% of the total root length of lupin and over 50% of subterranean clover were distributed in that layer. Plants grown without added nitrate for 105 days decreased soil pH at all layers but more significantly in the top 20 cm (by up to 0.7 units); the decrease in pH correlated well with increased root length density of both species (r 2 = 0 .9 8 , n = 9). The addition of Ca(NO3)2 to the top 10-cm layer caused less acidification by about 0.1 pH units at all depths than the treatment without Ca(NO3)2 . Where basal nutrients were applied uniformly throughout the column, root length density of lupin and subterranean clover tended to increase with depth. The addition of (NH4)2SO4 in the top 10 cm significantly increased NO3– concentration in all layers but NH4+ was mainly retained in the top 30-cm layer. Lupin and subterranean clover grown without added NH4+ for 82 days decreased soil pH by 0.3 units at all depths. Compared with the plants receiving no (NH4)2SO 4 , lupin grown with (NH4)2SO4 at 0–10 cm depth in the column caused more acidification by 0.05–0.2 pH units in the top 10 cm but less acidification by 0.15–0.17 units at 10–40 cm depth in the column; subterranean clover grown with (NH4)2SO4 caused more acidification by 0.35–0.46 units in the top 10 cm and less acidification by 0.14–0.19 units in the 20–50 cm layer. The results suggest that the leaching of nitrate from topsoil is unlikely to cause subsoil acidification. In contrast, the uptake of nitrate by the roots reduces net acid production in subsoil layers.

Soil acidity and growth of a legume. I. Interactions of lime with nitrogen and phosphate on growth of Medicago sativa L. and Trifolium subterraneum L.

1965 ◽  
Vol 16 (5) ◽  
pp. 733 ◽  
Author(s):  
DN Munns
Keyword(s):  
Medicago Sativa ◽  
Ammonium Nitrate ◽  
Potassium Carbonate ◽  
Soil Acidity ◽  
Acid Soils ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Aluminium Toxicity ◽  
Practical Advantage ◽  
Medicago Sativa L

Lucerne grew poorly without lime on several acid soils on which subterranean clover grew normally. On the moderately acid soils, of pH 5.5–6.0, most of the lime response by lucerne could be attributed to improvement in nodulation and could be eliminated by supplying ammonium nitrate. Strains of medic Rhizobium differed in ability to nodulate lucerne plants in acid soils sufficiently to suggest practical advantage in selecting strains for superiority in this respect. On the more acid soils, of pH 5.0–5.5, lucerne responded to lime or potassium carbonate even when not nitrogen-deficient. This lime response was eliminated by large applications of phosphate. The interaction between lime and phosphate could indicate aluminium toxicity.

Osmotic stress induced root growth and regulation of root development related genes in progenitors of wheat

2020 ◽  
Vol 80 (03) ◽  
Author(s):  
Monika Dalal ◽  
Sneha Tiwari ◽  
Vinod .
Keyword(s):  
Osmotic Stress ◽  
Root Growth ◽  
Root Length ◽  
Molecular Genetic ◽  
Aegilops Tauschii ◽  
Primary Root ◽  
Root Traits ◽  
Aegilops Speltoides ◽  
Good Resource ◽  
Primary Root Length

Maintenance of root growth during water deficit can significantly contribute to yield stability. In this study, total nine accessions, three each of Triticum monococcum, Aegilops speltoides and Aegilops tauschii were analysed for root traits under two levels of osmotic stress at seedling stage. T. monococcum accession (A2) showed highest increase in total root growth while 17% and 34% increase in primary root length was recorded in T. monococcum (A2) and Ae. speltoides (B3) under osmotic stress. Expression of BREVIS RADIX (BRX) and NAM/ATAF/CUC 1(NAC1) was analysed in three diploid accessions with contrasting root phenotype. BREVIS RADIX, a transcription factor modulating root length was up regulated in T. monococcum A2 accession while NAC1 expression was up regulated in three of the accessions under osmotic stress. The accessions and genes analysed in the study can be good resource to explore the molecular-genetic mechanism of root growth under stress.

scholarly journals Genetic Variability in Root and Shoot Growth Characteristics of Peanut1,2

1982 ◽  
Vol 9 (2) ◽  
pp. 68-72 ◽  
Author(s):  
D. L. Ketring ◽  
W. R. Jordan ◽  
O. D. Smith ◽  
C. E. Simpson
Keyword(s):  
Root Growth ◽  
Leaf Area ◽  
Root Length ◽  
Shoot Growth ◽  
Primary Root ◽  
Positive Association ◽  
Dry Weight ◽  
Root Parameters ◽  
Shoot Dry Weight ◽  
Highly Correlated

Abstract The shape and extent of root systems influence the rate and pattern of nutrient and water uptake from the soil. In dicotyledons such as peanut (Arachis hypogaea L.), the primary root and its laterals constitute the main root system. Rooting trait differences in some crops have been associated with drought tolerance. Our objective in this study was to determine if variation in root length and number occurs among peanut genotypes. In one test, shoot and root growth of 23 genotypes (12 spanish and 11 virginia types) were compared in the greenhouse at 55 days after planting using clear acrylic tubes 7.5 cm in diameter and 2.2 m in length. Shoot dry weight, leaf area, tap root length, and root number at 1 m depth ranged for spanish-type entries from 1.23 to 2.65 g, 214 to 409 cm2, 95.0 to 186.8 cm, and 1.0 to 3.1, respectively. Similarly, ranges for virginia-type entries were 1.35 to 3.23 g, 135 to 460 cm2, 122.4 to 192.6 cm, and 1.0 to 7.1. Correlations between shoot and root parameters indicated strong positive association between aerial and subterranean growth. However, the relationship of leaf area to root length was stronger for virginia- than for spanish-type entries. Root length and numbers were highly correlated for spanish, but not for virginia entries. In other tests that included two each of virginia-, spanish-, and valencia-type entries, similar results were found for plants at 34 and 47 days after planting. Significant differences in both root (length and numbers) and shoot growth (dry weight and leaf area) were found among the genotypes tested. Inherent differences in root growth rate were evident at early stages of seedling growth. The results from this sample of peanut germplasm indicate that there is considerable diversity in root growth and there is high shoot/root growth association.

A genome-wide association study reveals that the glucosyltransferase OsIAGLU regulates root growth in rice

2020 ◽  
Author(s):  
Jia Zhao ◽  
Bin Yang ◽  
Wenjun Li ◽  
Shan Sun ◽  
Liling Peng ◽  
...  
Keyword(s):  
Root Growth ◽  
Root Length ◽  
Crop Improvement ◽  
Primary Root ◽  
Genome Wide Association ◽  
Genome Wide Association Studies ◽  
Genome Wide ◽  
A Genome ◽  
Crown Roots ◽  
Primary Root Length

Abstract Good root growth in the early post-germination stages is an important trait for direct seeding in rice, but its genetic control is poorly understood. In this study, we examined the genetic architecture of variation in primary root length using a diverse panel of 178 accessions. Four QTLs for root length (qRL3, qRL6, qRL7, and qRL11) were identified using genome-wide association studies. One candidate gene was validated for the major QTL qRL11, namely the glucosyltransferase OsIAGLU. Disruption of this gene in Osiaglu mutants reduced the primary root length and the numbers of lateral and crown roots. The natural allelic variations of OsIAGLU contributing to root growth were identified. Functional analysis revealed that OsIAGLU regulates root growth mainly via modulating multiple hormones in the roots, including levels of auxin, jasmonic acid, abscisic acid, and cytokinin. OsIAGLU also influences the expression of multiple hormone-related genes associated with root growth. The regulation of root growth through multiple hormone pathways by OsIAGLU makes it a potential target for future rice breeding for crop improvement.

Effects of soil temperature on root growth and on phosphate uptake along Pinus radiata roots

Soil Research ◽  
1970 ◽  
Vol 8 (1) ◽  
pp. 31 ◽  
Author(s):  
GD Bowen
Keyword(s):  
Root Growth ◽  
Soil Temperature ◽  
Nutrient Solution ◽  
Pinus Radiata ◽  
Root Length ◽  
Phosphate Uptake ◽  
Lateral Roots ◽  
Primary Root ◽  
Ion Uptake ◽  
Scanning Method

At 3 weeks, uptake of phosphate along roots of seedlings grown in soil at 25�C was greatest in the apical centimetre and decreased sharply along the roots. By contrast uptake was markedly more sustained along the roots of seedlings grown in soil at 14�C and here the greatest uptake occurred several centimetres behind the apex. No one pattern of ion uptake along roots can be assumed to hold for all conditions of growth when constructing mathematical models of ion uptake from soil. Increasing soil temperature from 15�C to 25�C approximately doubled total root length of 3-week seedlings of Pinus radiata; primary root length was increased but the main effect was due toa marked increase in the number and length of lateral roots. Lateral root growth of the 3-week seedlings was almost completely suppressed in the soil at 11�C. Roots of 3-week sterile seedlings growing in phosphate-deficient nutrient solution were considerably smaller than those of pine grown in complete nutrient solution at 15�C but not at 25�C. This interaction of temperature and phosphate deficiency did not occur with soil grown seedlings. The sustained phosphate uptake along roots grown at the low soil temperature did not compensate for greater root growth (and therefore soil exploration) at higher temperatures, for P content of 3-week seedlings grown in soil at 25�C was considerably greater than that of seedlings grown in soil at 15�C. In phosphate poor soils low temperature depression of root growth will seriously restrict phosphate uptake. A modification of the scanning method for uptake sites along roots showed translocation to occur from all parts of the root with rather less translocation from the apical centimetre than from other parts.

Effect of waterlogging and soil pH on the micro-distribution of naturalised annual legumes

1997 ◽  
Vol 48 (2) ◽  
pp. 223 ◽  
Author(s):  
M. R. Gibberd ◽  
P. S. Cocks
Keyword(s):  
Root Growth ◽  
Soil Ph ◽  
Soil Seed Bank ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dry Weight ◽  
Waterlogging Tolerance ◽  
Patchy Distribution ◽  
Shoot Dry Weight ◽  
Waterlogging Treatment

Variation in the size and composition of the soil seed bank of 3 naturalised legumes, subterranean clover (Trifolium subterraneum L.), woolly clover (T. tomentosum L.), and cluster clover (T. glomeratum L.), was related to soil characteristics on a transect that ascended from a winter waterlogged area in a wheatbelt pasture. Growth of the 3 species was compared with other species from section Vesicaria (T. resupinatum and T. clusii) in waterlogged and freely drained pots for 34 days. Of the 3 naturalised legumes present in the transect, cluster clover was rare, and woolly and subterranean clovers were separated on the basis of their response to soil pH and the likelihood of winter waterlogging. Subterranean clover was absent from soil with pH > 7·0; these areas were dominated by woolly clover. Areas with pH < 7·0 were dominated by subterranean clover, except where winter waterlogging was likely, in which case they were once again dominated by woolly clover. The waterlogging tolerance of woolly clover, together with that of other species in section Vesicaria, was confirmed in the pot experiment. After 34 days, shoot dry weight of the waterlogged Vesicaria species was an average of 39% greater than the freely drained controls. Root length continued to increase for the duration of the waterlogging treatment with much of the new root growth as laterals. Conversely, shoot and root growth in subterranean and cluster clovers was severely reduced by waterlogging. The patchy distribution of woolly clover in many wheatbelt pastures can be explained by its response to high pH and winter waterlogging compared with subterranean clover.

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