PEG-Induced Osmotic Stress Alters Root Morphology and Root Hair Traits in Wheat Genotypes

Wheat crop in drought-prone regions of Bangladesh suffers from osmotic stress. The objective of this study was to investigate the response of wheat genotypes with respect to root morphology and root hair traits under polyethylene glycol (PEG)-induced osmotic stress. A total of 22 genotypes of wheat were grown hydroponically and two treatments—0% and 10% PEG—were imposed at 14 days after germination. Plant growth was reduced in terms of plant height, number of live leaves per tiller, shoot dry weight, number of root-bearing phytomers, and roots per tiller. Notably, PEG-induced osmotic stress increased root dry weight per tiller by increasing length of the main axis and lateral roots, as well as the diameter and density of both lateral roots and root hairs of the individual roots. A biplot was drawn after a principal component analysis, taking three less-affected (high-yielding genotypes) and three highly affected (low-yielding genotypes and landrace) genotypes under 10% PEG stress, compared to control. Principal component 1 separated PEG-treated wheat genotypes from control-treated genotypes, with a high and positive coefficient for the density of lateral roots and root hairs, length and diameter of the main axis, and first-order lateral roots and leaf injury scores, indicating that these traits are associated with osmotic stress tolerance. Principal component 2 separated high-yielding and tolerant wheat genotypes from low-yielding and susceptible genotypes, with a high coefficient for root dry weight, density of root hairs and second-order lateral roots, length of the main axis, and first-order lateral roots. An increase in root dry weight in PEG-stress-tolerant wheat genotypes was achieved through an increase in length and diameter of the main axis and lateral roots. The information derived from this research could be exploited for identifying osmotic stress-tolerant QTL and for developing abiotic-tolerant cultivars of wheat.

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Selection of drought tolerant wheat genotypes by osmotic stress imposed at germination and early seedling stage

SAARC Journal of Agriculture ◽

10.3329/sja.v15i2.35147 ◽

2018 ◽

Vol 15 (2) ◽

pp. 177-192

Author(s):

RR Saha ◽

A Hannan ◽

A Nessa ◽

MA Malek ◽

MR Islam

Keyword(s):

Osmotic Stress ◽

Dry Weight ◽

Seedling Stage ◽

Metabolic Efficiency ◽

Wheat Genotypes ◽

Shoot Dry Weight ◽

Vigour Index ◽

Peg Treatment ◽

Early Seedling ◽

Different Levels

An experiment on hundred wheat genotypes under different levels of osmotic stress was carried out during 2014 to select the genotype(s) tolerant to drought at germination and early seedling stage. Different levels of osmotic stress were imposed by using polyethylene glycol (PEG). Three osmotic stress levels viz. control (distilled water), 15% PEG solution and 25% PEG solution were used. Among the 100 genotypes the rate of germination percentage, final germination (%), root and shoot dry weight, amount of respiration and vigour index under PEG treatment was found significantly lower than that of control condition. Compared to control condition relative decrease in rate of germination, final germination, amount of respiration and vigour index among the wheat genotypes were found more at 25% PEG than that of 15% PEG treatment. However, the seed metabolic efficiency was significantly higher in wheat genotypes under both 15% PEG and 25% PEG treatment compared to the control condition. A significant positive correlation exists between the important growth parameters like rate of germination (%), final germination (%), shoot dry weight, root dry weight and vigour index. On the basis of these physiological traits against osmotic stress, nine genotypes of wheat such as BD-480, BD-498, BD- 501, BD-513, BD-514, BD-519, BD-592, BD-618 and BD- 633 were selected as drought tolerant.SAARC J. Agri., 15(2): 177-192 (2017)

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IDENTIFICATION OF DROUGHT TOLERANT WHEAT GENOTYPES UNDER WATER DEFICIT CONDITIONS

International Journal of Research -GRANTHAALAYAH ◽

10.29121/granthaalayah.v4.i2.2016.2830 ◽

2016 ◽

Vol 4 (2) ◽

pp. 206-214 ◽

Cited By ~ 1

Author(s):

Zaid Chachar ◽

N. A. Chachar ◽

Q.I. Chachar ◽

S.M Mujtaba ◽

G.A Chachar ◽

...

Keyword(s):

Water Stress ◽

Seed Germination ◽

Osmotic Stress ◽

Root Length ◽

Dry Weight ◽

Shoot Length ◽

Wheat Genotypes ◽

Maximum Reduction ◽

Drought Tolerant

Climate change is emerging phenomena and causing frequent drought which lead to scaricity of water, which ultimately nagetively affecting wheat (Triticumaestivum L.) yield all around the world. The aim of this study was to explore the potential deought tolerant wheat genotypes for candidate genes exploration. This study was conducted during the year 2014-2015 at Plant Physiology Division, Nuclear Institute of Agriculture (NIA) Tandojam. The six wheat genotypes (cv. MT-1/13, MT-2/13, MT-3/13, MT-4/13 Chakwal-86 and Khirman) were investigated for their response at germination and seedling stage under different water stress treatments (0, -0.5, -0.75 and -1.0 MPa) in controlled conditions. The results of experiments with reference to genotypes revealed that genotype Chakwal-86 shows maximum seed germination (82.58 %), while the genotype Khirman shows maximum shoot length (7.23 cm), root length (15.1 cm), shoot fresh wt. (5.85 g 10-1shoots), root fresh wt. (3.45 g 10-1roots), shoot dry wt. (1.33 g 10-1shoots), root dry wt. (0.69 g 10-1roots). Among the genotypes tested Khirman and MT-4/13 are the tolerant genotypes had the potential to perform better under drought conditions, whereas MT-4/13 and Chakwal-86 were moderate tolerant under water stress conditions. Moreover, the genotypes i.e. MT-1/13 and MT-2/13 are the sensitive genotypes under drought environment. It is concluded from present in-vitro studies that osmotic stress significantly reduced the seed germination shoot/root length fresh and dry weight in all six wheat genotypes. The maximum reduction was found at higher osmotic stress induced by PEG-6000 (-1.0 MPa) significantly.

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Genotypic variations in root traits of wheat varieties at phytomer level

Journal of the Bangladesh Agricultural University ◽

10.3329/jbau.v12i1.21238 ◽

2014 ◽

Vol 12 (1) ◽

pp. 45-54 ◽

Cited By ~ 8

Author(s):

AHK Robin ◽

MJ Uddin ◽

S Afrin ◽

PR Paul

Keyword(s):

Root Hair ◽

Significant Variation ◽

Root Traits ◽

Dry Weight ◽

Main Axis ◽

Hair Density ◽

Wheat Varieties ◽

First Order ◽

Root Hair Density ◽

Axis Length

The aims of this study were to investigate genotypic variations in root traits at phytomer level of wheat varieties and for recommending a few root traits as selection parameters in future breeding programs. Two separate experiments were conducted to measure their root traits for hydroponically grown wheat plants. In Experiment 1, main axis length, root hair density and diameter differed from phytomer to phytomer at 60 days after sowing for two varieties, Shotabdi and Sonalika. Density of first order laterals at their axis of origin, dry weights of roots and shoots and root:shoot ratio varied significantly among 8 varieties. In Experiment 2, number of root bearing phytomer, total number of adventitious roots, main axis length at root bearing phytomer 1 and 2 (youngest roots were the reference point and numbered as phytomer 1), length of first order laterals at phytomer 3, root hair density and dry weights of roots and shoots were significantly different among varieties. PC1 (principal component 1) resulted in significant variation among varieties for number of live leaves, new roots appeared, number of root bearing phytomer, total number of adventitious roots, root dry weight and shoot dry weight. PC2 yielded significant difference among varieties for live leaves, main axes length at phytomer 1 & 2, number of new roots, root hair density and diameter. Selection of varieties based on main axes length at the youngest phytomer & root hair density per unit surface area along with dry weights of roots and shoots could be recommended for future breeding program as these four parameters consistently resulted in significant variation among varieties. DOI: http://dx.doi.org/10.3329/jbau.v12i1.21238 J. Bangladesh Agril. Univ. 12(1): 45-54, June 2014

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Auxin stimulates lateral root formation of container-grown interior Douglas-fir seedlings

Canadian Journal of Forest Research ◽

10.1139/x86-199 ◽

1986 ◽

Vol 16 (5) ◽

pp. 1135-1139 ◽

Cited By ~ 8

Author(s):

David G. Simpson

Keyword(s):

Lateral Root ◽

Root Formation ◽

Lateral Roots ◽

Dry Weight ◽

Douglas Fir ◽

Lateral Root Formation ◽

Indolebutyric Acid ◽

Shoot Height ◽

First Order ◽

Napthaleneacetic Acid

The effects of 1-napthaleneacetic acid (NAA) and 3-indolebutyric acid (IBA) soil drenches on lateral root formation and growth of interior Douglas-fir (Pseudotsugamenziesii var. glauca (Beissn.) Franco) seedlings were studied. At rates between 10−3 and 10−5 M, NAA was more effective than IBA in stimulating first-order lateral root formation. Seedling age influenced the degree of NAA-induced lateral root formation. At three different nurseries the greatest number of lateral roots was produced by seedlings receiving 10−4 M (18.62 mgL−1) NAA 30 days after sowing. Shoot height and dry weight were reduced, although not at the expense of root growth in some cases.

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Root Hairs and Root Lengths in Nine Warm-season Turfgrass Genotypes

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.116.6.965 ◽

1991 ◽

Vol 116 (6) ◽

pp. 965-969 ◽

Cited By ~ 8

Author(s):

R.L. Green ◽

J.B. Beard ◽

M.J. Oprisko

Keyword(s):

Root Length ◽

Cynodon Dactylon ◽

Lateral Roots ◽

Root Hairs ◽

Warm Season ◽

Total Root Length ◽

Zoysia Japonica ◽

Main Root ◽

First Order ◽

Eremochloa Ophiuroides

Root hairs contributed variously to total root length, ranging from a low of 1% for `Emerald' zoysiagrass (Zoysia japonica Steud. x Z. tenuifolia Willd. ex Trin) and 5% for `Georgia Common' centipedegrass [Eremochloa ophiuroides (Munro.) Hack], to a high of 95% and 89% for `Texturf 10' and `FB 119' bermudagrasses [Cynodon dactylon (L.) Pers.], respectively. Genotypes ranking highest for root lengths with root hairs also ranked highest for root lengths without root hairs and for number of main roots per plant. In terms of root lengths with root hairs, first-order lateral roots contributed more to total root length than root lengths of either main roots or second-order lateral roots for all nine genotypes. Number and length of root hairs arising from either main or lateral roots were not significantly affected by their relative distance from the cap of the main root. `Texturf 10' and `FB 119' bermudagrasses ranked highest for root and root-hair extent.

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Root Pruning and Auxin Alter Root Morphology of Hickories

HortScience ◽

10.21273/hortsci14026-19 ◽

2019 ◽

Vol 54 (9) ◽

pp. 1517-1520

Author(s):

Brandon M. Miller ◽

William R. Graves

Keyword(s):

Lateral Roots ◽

Dry Weight ◽

Shoot Development ◽

Subsequent Treatment ◽

Root Pruning ◽

Coarse Root ◽

Root Branching ◽

First Order ◽

Shoot Dry Weight ◽

Carya Ovata

A reputation for coarse root systems with dominant taproots, and for slow shoot development among seedlings, limits use of hickory species (Carya Nutt.) that could increase diversity in managed landscapes. We examined effects of root pruning and application of auxin on root and shoot development of seedlings of several species of hickory. Our hypothesis was that pruning the radicle shortly after seed germination and subsequent treatment with auxin would increase root branching without curtailing development of the shoot. Germinated seeds of Carya aquatica (F. Michx.) Nutt., Carya cordiformis (Wangenh.) K. Koch, Carya laciniosa (F. Michx.) Loudon, Carya ovata (Mill.) K. Koch, and Carya tomentosa (Lam.) Nutt. were treated by removing two-thirds of the length of the radicle with and without immediate application of 3000 mg·L−1 indole-3-butyric acid (IBA) via Hormex rooting powder #3 to the remaining one-third of radicle. Neither treatment altered stem height, stem caliper, or root dry weight. After 75 days, root-pruned seedlings of Carya ovata without auxin had 42% fewer fibrous first-order lateral roots than did unpruned controls. Root pruning plus auxin led to a 79% increase in the number of fibrous first-order lateral roots of C. laciniosa and an ≈50% increase in the shoot dry weight of C. aquatica. Both root pruning and root pruning plus auxin evoked formation of taproot branches for all species. Because species differed in responses of root and shoot systems to root pruning with and without auxin, the practice should be implemented cautiously based on the species.

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Combining Physiological and Metabolomic Analysis to Unravel the Regulations of Coronatine Alleviating Water Stress in Tobacco (Nicotiana tabacum L.)

Biomolecules ◽

10.3390/biom10010099 ◽

2020 ◽

Vol 10 (1) ◽

pp. 99 ◽

Cited By ~ 3

Author(s):

Jiayang Xu ◽

Yuyi Zhou ◽

Zicheng Xu ◽

Zheng Chen ◽

Liusheng Duan

Keyword(s):

Osmotic Stress ◽

Dry Weight ◽

Plant Tolerance ◽

Enzyme Activity Assay ◽

Nicotiana Tabacum L ◽

Ros Accumulation ◽

Metabolite Profiles ◽

Sugar Derivatives ◽

Nitrogen Containing Compounds ◽

Peg Stress

Drought is a major abiotic stress that restricts plants growth, development, and yield. Coronatine (COR), a mimic of JA-Ile, functions in plant tolerance to multiple stresses. In our study, we examined the effects of COR in tobacco under polyethylene glycol (PEG) stress. COR treatment improved plant growth under stress as measured by fresh weight (FW) and dry weight (DW). The enzyme activity assay indicated that, under osmotic stress conditions, the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) were enhanced by COR treatment. Histochemical analyses via nitrotetrazolium blue chloride (NBT) and 3,3′-diaminobenzidine (DAB) staining showed that COR reduced reactive oxygen species (ROS) accumulation during osmotic stress. Metabolite profiles revealed that COR triggered significant metabolic changes in tobacco leaves under osmotic stress, and many essential metabolites, such as sugar and sugar derivatives, organic acids, and nitrogen-containing compounds, which might play active roles in osmotic-stressed tobacco plants, were markedly accumulated in the COR-treated tobacco. The work presented here provides a comprehensive understanding of the COR-mediated physiological, biochemical, and metabolic adjustments that minimize the adverse impact of osmotic stress on tobacco.

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Salinity Stress Alters Root Morphology and Root Hair Traits in Brassica napus

Plants ◽

10.3390/plants8070192 ◽

2019 ◽

Vol 8 (7) ◽

pp. 192 ◽

Cited By ~ 9

Author(s):

Mohammad Rashid Arif ◽

M. Thoihidul Islam ◽

Arif Hasan Khan Robin

Keyword(s):

Lateral Roots ◽

Root Hairs ◽

Root Traits ◽

Morphological Plasticity ◽

Root Surface ◽

Root Surface Area ◽

Third Order ◽

Breeding Programs ◽

First Order ◽

Treated Condition

Plant roots show morphological plasticity and play a substantial role in tolerance to various edaphic stresses. The aim of this study was to explore salinity-induced morphogenic responses of root traits and root hairs of two rapeseed varieties, BARI Sarisha-8 and Binasarisha-5, at the reproductive stage and perceive the effects on their reproductive growth. The experiment was conducted in a hydroponic culture. Two treatments, 0 mM NaCl as control and 100 mM NaCl, were imposed 55 d after germination. Plants exposed to 100 mM NaCl for seven days displayed greater damage in the leaves, flowers, and siliquae compared to control. Length of root hairs on first-order and third-order lateral roots, density of root hairs on first-order lateral roots, and length of third-order lateral roots were significantly greater by 91%, 22%, 29%, and 48%, respectively, in the treated condition compared to the control. An increase in estimated root surface area by 20% under salt stress conditions indicated that the spontaneous responses of plants to uptake more water and nutrients allowed a plant to cope with stressful conditions. The results of this study suggest that any future stress breeding programs should consider plasticity of root traits intensively.

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Rooting `Yoshino' Cryptomeria Stem Cuttings as Influenced by Growth Stage, Branch Order, and IBA Treatment

HortScience ◽

10.21273/hortsci.29.12.1532 ◽

1994 ◽

Vol 29 (12) ◽

pp. 1532-1535 ◽

Cited By ~ 1

Author(s):

Laura G. Jull ◽

Stuart L. Warren ◽

Frank A. Blazich

Keyword(s):

Root Length ◽

Growth Stage ◽

Dry Weight ◽

Second Order ◽

Stem Cuttings ◽

Total Root Length ◽

Branch Order ◽

First Order ◽

Root Dry Weight ◽

Root Area

Stem cuttings of `Yoshino' Japanese cedar [Cryptomeria japonica (L.f.) D. Don `Yoshino'], consisting of tips (terminal 20 cm) of first-order laterals, distal halves (terminal 10 cm) of tips of first-order laterals, and proximal halves (basal 10 cm) of tips of first-order laterals, or tips (terminal 10 cm) of second-order laterals, were taken on four dates that represented four growth stages (softwood, semi-hardwood, hardwood, and pre-budbreak). The cuttings were treated with 0, 3000, 6000, or 9000 mg IBA/liter. Branch order affected all rooting measurements at each growth stage. Regardless of growth stage, tips of and proximal halves of first-order laterals containing lignified wood had the highest percent rooting, root count, total root length, root area, and root dry weight. Hardwood tips of and semi-hardwood proximal halves of first-order laterals exhibited the highest overall rooting (87%), followed by softwood proximal halves of first-order laterals (78%). Rooting of distal halves of first-order laterals and tips of second-order laterals never exceeded 55% and 34%, respectively, at any growth stage. IBA treatment influenced percent rooting, root count, total root length, root area, and root dry weight of semi-hardwood, hardwood, and pre-budbreak cuttings, except for root dry weight of semi-hardwood cuttings. IBA had no affect on softwood cuttings. Chemical name used: 1H-indole-3-butyric acid (IBA).

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Root Distribution and Mineral Uptake of Coarse-rooted Trees Grown in Cupric Hydroxide-treated Containers

HortScience ◽

10.21273/hortsci.28.10.988 ◽

1993 ◽

Vol 28 (10) ◽

pp. 988-992 ◽

Cited By ~ 9

Author(s):

Michael A. Arnold ◽

Daniel K. Struve

Keyword(s):

Lateral Roots ◽

Dry Weight ◽

Growing Season ◽

Black Walnut ◽

White Oak ◽

Total N ◽

Chinese Chestnut ◽

Root Dry Weight ◽

Cupric Hydroxide ◽

Sawtooth Oak

Seedlings of nine coarse-rooted species–sawtooth oak (Quercus acutissima Carruth), white oak (Q. alba L.), cherrybark oak (Q. falcata var. pagodifolia Elliott), post oak (Q. stellata Wangenh.), black walnut (Juglans nigra L.), pignut hickory [Carya glabra (Mill.) Sweet], pecan [C. illinoinensis (Wangenh.) C. Koch], Chinese chestnut (Castanea mollissima Blume), and common baldcypress [Taxodium distichum (L.) L. Rich]—were grown for one growing season in nontreated containers or in containers treated on their interior surfaces with white interior latex paint containing 100 g Cu(OH)2/liter. Seedlings of each species and container treatment were harvested twice: once after being transplanted from 3.2- to 15.0-liter containers and at the end of the growing season. Cupric hydroxide-treated containers decreased the amount of circled, kinked, and matted roots formed at the container wall-medium interface in all species tested. Plants grown in Cu(OH)2-treated containers also had altered root dry-weight partitioning. The partitioning patterns were species specific and included 6% to 20% increases in the percentage of root dry weight in interior vs. exterior portions of the rootball (white oak, black walnut, Chinese chestnut, and baldcypress), 10% to 21% increases in the percentage of root dry weight in upper vs. lower halves of the rootball (sawtooth oak, cherrybark oak, black walnut, and baldcypress), and an increase in the percentage of primary lateral roots (lateral roots originating from taproots or roots functioning as taproots) on the upper (proximal) half of taproots (cherrybark oak, pecan, and baldcypress). Nutrients in leaves, stems, and roots of sawtooth oak seedlings were analyzed at both harvests. Seedlings grown in Cu(OH)2-treated containers had more Cu in most plant tissues than nontreated seedlings. Also, seedlings grown in Cu(OH)2-treated containers had higher total Ca and Mg concentrations at transplanting and higher total N and Zn concentrations at the end of the growing season than nontreated seedlings.

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