scholarly journals Root Growth of Avocado is More Sensitive to Salinity than Shoot Growth

2004 ◽  
Vol 129 (2) ◽  
pp. 188-192 ◽  
Author(s):  
N. Bernstein ◽  
A. Meiri ◽  
M. Zilberstaine
Keyword(s):  
Salt Stress ◽  
Root Growth ◽  
Biomass Production ◽  
Root Elongation ◽  
Shoot Growth ◽  
Elongation Rate ◽  
Persea Americana ◽  
Root Growth Inhibition ◽  
Leaf Biomass ◽  
Volumetric Growth

In most crop species, growth of the shoot is more sensitive to salt stress than root growth. Avocado [Persea americana Mill.] is very sensitive to NaCl stress. Even low concentrations of salt (15 mm) inhibit tree growth and decrease productivity. Observations in experimental orchards have suggested that root growth in avocado might be more restricted by salinity than shoot growth. In the present study, we evaluated quantitatively the inhibitory effects of salt stress on growth of the avocado root in comparison to the shoot. Seedling plants of the West-Indian rootstock `Degania 117' were grown in complete nutrient solution containing 1, 5, 15, or 25 mm NaCl. The threshold NaCl concentration causing root and shoot growth reduction occurred between 5 and 15 mm. At all concentrations, root growth was much more sensitive to salinity than shoot growth. A concentration of 15 mm NaCl, which did not affect the rate of leaf emergence on the plant and decreased leaf biomass production only 10%, induced a 43% reduction in the rate of root elongation and decreased root volumetric growth rate by 33%. Under 25 mm NaCl, leaf biomass production, leaf initiation rate and leaf elongation rate were reduced 19.5%, 12%, and 5%, respectively, while root volumetric growth and root elongation rate were reduced 65% and 75%, respectively. This strong root growth inhibition is expected to influence the whole plant and therefore root growth under salinity should be considered as an important criterion for rootstocks' tolerance to NaCl.

Genetic variation in the root growth response of barley genotypes to salinity stress

2013 ◽  
Vol 40 (5) ◽  
pp. 516 ◽  
Author(s):  
Megan C. Shelden ◽  
Ute Roessner ◽  
Robert E. Sharp ◽  
Mark Tester ◽  
Antony Bacic
Keyword(s):  
Genetic Variation ◽  
Salt Stress ◽  
Root Growth ◽  
Salinity Stress ◽  
Early Phase ◽  
Root Elongation ◽  
Wild Barley ◽  
Seminal Root ◽  
Biochemical Characterisation ◽  
Barley Genotypes

We aimed to identify genetic variation in root growth in the cereal crop barley (Hordeum vulgare L.) in response to the early phase of salinity stress. Seminal root elongation was examined at various concentrations of salinity in seedlings of eight barley genotypes consisting of a landrace, wild barley and cultivars. Salinity inhibited seminal root elongation in all genotypes, with considerable variation observed between genotypes. Relative root elongation rates were 60–90% and 30–70% of the control rates at 100 and 150 mM NaCl, respectively. The screen identified the wild barley genotype CPI71284–48 as the most tolerant, maintaining root elongation and biomass in response to salinity. Root elongation was most significantly inhibited in the landrace Sahara. Root and shoot Na+ concentrations increased and K+ concentrations decreased in all genotypes in response to salinity. However, the root and shoot ion concentrations did not correlate with root elongation rates, suggesting that the Na+ and K+ concentrations were not directly influencing root growth, at least during the early phase of salt stress. The identification of genetic diversity in root growth responses to salt stress in barley provides important information for future genetic, physiological and biochemical characterisation of mechanisms of salinity tolerance.

A method to identify lupin species tolerant of alkaline soils

1996 ◽  
Vol 36 (5) ◽  
pp. 595 ◽  
Author(s):  
C Tang ◽  
H Adams ◽  
NE Longnecker ◽  
AD Robson
Keyword(s):  
Root Elongation ◽  
Shoot Growth ◽  
Culture Method ◽  
Solution Culture ◽  
Elongation Rate ◽  
Iron Chlorosis ◽  
Alkaline Soil ◽  
Alkaline Soils ◽  
Root Elongation Rate ◽  
Shoot Weight

Narrow-leafed lupins (Lupinus angustifolius L.) grow poorly on alkaline soils. In contrast, L. pilosus Murr. and L. atlanticus Glad. grow well on such soils. This study aimed to develop a solution culture method to screen lupin species for their ability to grow well on alkaline soils. Sixteen lupin genotypes from 6 species, including introduced cultivars and wild types, were grown in high pH solutions with varying concentrations of buffers and bicarbonate. Relative taproot elongation, shoot growth and iron chlorosis were compared with iron chlorosis, relative shoot growth and seed yield for the same genotypes on an alkaline soil in the field. The results suggested that root elongation rate at pH 7 in solution buffered with a mixture of 1 mmol MES/L and 1 mmol TESL (plus 10 mmol CaCl2/L), and shoot weight at 5 mmol bicarbonate/L at pH 8.7 are good indicators of tolerance to an alkaline soil among the lupin species.

Root Growth Inhibition and Lignification Induced by Salt Stress in Soybean

2010 ◽  
Vol 196 (6) ◽  
pp. 467-473 ◽  
Author(s):  
G. Y. S. Neves ◽  
R. Marchiosi ◽  
M. L. L. Ferrarese ◽  
R. C. Siqueira-Soares ◽  
O. Ferrarese-Filho
Keyword(s):  
Salt Stress ◽  
Root Growth ◽  
Growth Inhibition ◽  
Root Growth Inhibition

Root growth and root growth capacity of white spruce (Piceaglauca (Moench) Voss) seedlings

1985 ◽  
Vol 15 (4) ◽  
pp. 625-630 ◽  
Author(s):  
Anne M. Johnson-Flanagan ◽  
John N. Owens
Keyword(s):  
Root Growth ◽  
Root Elongation ◽  
Shoot Growth ◽  
Lateral Roots ◽  
White Spruce ◽  
Shoot Elongation ◽  
Growth Capacity ◽  
Root Growth Capacity ◽  
Root And Shoot Growth

Root growth in the root systems of Styroplug-grown white spruce (Piceaglauca (Moench) Voss) seedlings increases in the spring before shoot elongation and again in the fall after bud development is complete. This is followed by root dormancy and quiescence, which are distinguished on the basis of ability to elongate under root growth capacity (RGC) conditions. The number of white long lateral roots produced during RGC tests correlated significantly with the number of white long lateral roots under lathhouse conditions. Increased mitotic activity is required for root elongation. However, mitotic frequencies could not be used to assess RGC because of the confounding effects of independent growth cycles in individual roots. Cell expansion and transformation of insoluble carbohydrates are important controls of root elongation. The relationship between root and shoot growth under RGC conditions may not support the role of shoot elongation in decreasing root elongation. Conversely, this may indicate that RGC tests alter the endogenous controls of root and shoot growth.

scholarly journals SWO1 modulates cell wall integrity under salt stress by interacting with importin ɑ in Arabidopsis

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Zhidan Wang ◽  
Mugui Wang ◽  
Changhong Yang ◽  
Lun Zhao ◽  
Guochen Qin ◽  
...  
Keyword(s):  
Cell Wall ◽  
Salt Stress ◽  
Double Mutant ◽  
Root Elongation ◽  
High Salinity ◽  
Cell Wall Integrity ◽  
Root Growth Inhibition ◽  
Rna Seq ◽  
Plant Growth And Development ◽  
Root Tips

AbstractMaintenance of cell wall integrity is of great importance not only for plant growth and development, but also for the adaptation of plants to adverse environments. However, how the cell wall integrity is modulated under salt stress is still poorly understood. Here, we report that a nuclear-localized Agenet domain-containing protein SWO1 (SWOLLEN 1) is required for the maintenance of cell wall integrity in Arabidopsis under salt stress. Mutation in SWO1 gene results in swollen root tips, disordered root cell morphology, and root elongation inhibition under salt stress. The swo1 mutant accumulates less cellulose and pectin but more lignin under high salinity. RNA-seq and ChIP-seq assays reveal that SWO1 binds to the promoter of several cell wall-related genes and regulates their expression under saline conditions. Further study indicates that SWO1 interacts with importin ɑ IMPA1 and IMPA2, which are required for the import of nuclear-localized proteins. The impa1 impa2 double mutant also exhibits root growth inhibition under salt stress and mutations of these two genes aggravate the salt-hypersensitive phenotype of the swo1 mutant. Taken together, our data suggest that SWO1 functions together with importin ɑ to regulate the expression of cell wall-related genes, which enables plants to maintain cell wall integrity under high salinity.

scholarly journals Boron deficiency-induced root growth inhibition is mediated by brassinosteroid signalling regulation in Arabidopsis

2019 ◽  
Author(s):  
Cheng Zhang ◽  
Mingliang He ◽  
Sheliang Wang ◽  
Liuyang Chu ◽  
Chuang Wang ◽  
...  
Keyword(s):  
Root Growth ◽  
Growth Inhibition ◽  
Root Elongation ◽  
Mrna Level ◽  
Root Growth Inhibition ◽  
Boron Deficiency ◽  
Sequencing Analysis ◽  
Nuclear Signal ◽  
Condition B

ABSTRACTBrassinosteroid (BR) is a pivotal phytohormone involved in regulating root development. Boron (B) is an essential micronutrient for plant growth and development, and root growth of plants is rapidly inhibited under B deficiency condition, but the mechanisms are still elusive. Here, we demonstrate that BR plays crucial roles in these processes. We identify BR-related processes underlying B deficiency at the physiological, genetic, molecular/cell biological and transcriptome levels, and provide strong evidences that B deficiency can affect BR signalling, thereby altering root growth. RNA-sequencing analysis reveals a high co-regulation between BR-regulated genes and B deficiency-responsive genes. We found that low B negatively regulates BR signalling to control BR signalling-dependent root elongation, bes1-D exhibits insensitivity to low B stress, and bri1-301 mutants fails to respond to B depletion. Exogenous eBL application can rescue the inhibition of root growth under B deficiency condition, and application of BR biosynthesis inhibitor BRZ aggravates root growth inhibition of wild-type under B deficiency condition. B deficiency reduces the nuclear signal of BES1. We further found that B deficiency reduces the accumulation of brassinolide (BL) by reducing BR6ox1 and BR6ox2 mRNA level to down-regulate BR signalling and modulate root elongation. Altogether, our results uncover a role of BR signalling in root elongation under B deficiency.One-sentence summaryB deficiency reduces the accumulation of brassinolide by reducing BR6ox1 and BR6ox2 mRNA level to down-regulate BR signalling and modulate root elongation.

scholarly journals SALINITY STRESS RESPONSES OF MINIATURE DWARF TOMATO IN A WHOLE PLANT MICROCULTURE EVALUATION SYSTEM

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1149c-1149
Author(s):  
M. A. L. Smith ◽  
S. L. Knight ◽  
M. J. Bass
Keyword(s):  
Root Growth ◽  
Stress Responses ◽  
Evaluation System ◽  
Time Course ◽  
Shoot Growth ◽  
Root Growth Inhibition ◽  
Plant Responses ◽  
Tissue Quality ◽  
Osmotic Concentration ◽  
Whole Plant

A whole plant microculture (WPMC) screening system facilitated rapid, quantitative appraisal of salt stress effects on `Micro-Tom' miniature dwarf tomato. Axillary bud explants were micropropagated on a hormone-free control medium (conductivity = 3.3 dS m-1), gradually introduced to treatments with increasing NaCl or Na2SO4 concentrations via biweekly subculture to fresh media (7,6, 12.8, or 18 dS m-1), and monitored over a subsequent 5 week culture period. Non-intrusive video image analysis techniques were adapted to quantify morphometric (shoot growth rate, area, and length; root length and area) and photometric (ruler and tissue quality) plant responses. Shoot growth was only slightly inhibited at 7.6 and 12.8 dS m-1, but was severely stunted and distorted on high salt (18 dS m-1) media. Root growth inhibition (significantly shorter and thinner primary rants) was first evident at 12.8 dS m-1 after 3 weeks of treatment. At 18 dS m-1, conspicuous retardation of root growth relative to controls could be gauged after only one week. Shoot tip chlorosis was observed in the lowest salt-supplemented treatment after three to four weeks of culture, but overall shoot yellowing at the two highest conductivities was marked after only a few days. Chlorosis symptoms were not uniform within treatments. Cell osmotic concentration showed a linear increase with increasing medium salinity. The WPMC system expedited time course observations of stress symptom development, paralleled stress response trends observed in solution culture tests, and provided an excellent vehicle to investigate plant adaptation to saline conditions.

scholarly journals ROOT AND SHOOT GROWTH AS INFLUENCED BY OVERHEAD AND FLOATATION IRRIGATION IN JALAPENO PEPPER TRANSPLANTS

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 592c-592
Author(s):  
Daniel I. Leskovar ◽  
Ronald R. Heineman
Keyword(s):  
Root Growth ◽  
Lateral Root ◽  
Root Elongation ◽  
Shoot Growth ◽  
Irrigation Systems ◽  
Growth Compensation ◽  
Length Increase ◽  
Root And Shoot Growth ◽  
Basal Roots ◽  
Water Holding

This study was conducted to investigate how irrigation systems alter root elongation, root morphology, shoot growth characteristics and yield of `TAM-M' jalapeno pepper seedlings. Transplants were grown in containerized trays (18 cm3/cell) for 6 weeks in a greenhouse in Spring 1991. Irrigation systems were: a) floatation (FI), b) 4-week floatation plus 2-week overhead (FI+OI); c) alternate floatation and overhead (FI/OI), and d) overhead (OI). The growing media was maintained between 50 and 20% of its water holding capacity. Between 20 and 41 days after seeding (DAS), FI and FI/OI transplants maintained a constant lateral root length increase. In both FI+OI and OI transplants, lateral root elongation response tended to a `plateau' at ≈ 31 DAS. However, between 31 and 41 DAS, OI transplants had a root growth compensation, increasing the number and length (33%) of basal roots. In FI+OI transplants, basal root growth compensation occurred later in the field. At planting, OI transplants had higher shoot/root ratio (S:R=5) and maintained a higher shoot water potential (ψ= -0.58 MPa) than FI transplants (S:R=3; ψ= -0.69 MPa), respectively. Overhead-irrigated transplants had higher early fruit yields than floatation-irrigated transplants, but total yields were unaffected.

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