Enhanced Adaptation to Low-P stress by Altering Rhizosphere Exudation and P-Uptake Rate other than Root Morphological Traits in Two Maize Genotypes

Alterations in root morphology and physiology are important strategies in plants to adapt to low-phosphorus (P) environments. Maize genotypes differed in nitrogen (N) efficiency may also respond differently to low P stress. This study aimed to investigate the responses of root morphological and physiological traits of these two maize cultivars to P deficit and how these traits were linked with the acquisition of soil P. Two maize cultivars, XY335 (N efficient) and ZD958 (N inefficient), were cultivated for 40 days in a calcareous loamy soil amended with (high P) or without (low P) P. Functional root traits were used to evaluate the morphological and physiological responses to low P supply. Two separate short-term experiments determined the correlation between P uptake rate and P supply intensity (hydroponic) or root hair length under two P treatments (rhizobox). Low P status significantly simulated biomass allocation to roots, specific root length and exudations of carboxylates, while decreased root diameter and rhizosphere pH in both maize cultivars. Two cultivars had different total root length and root surface area under low P stress: increased in ZD958 and decreased in XY335. Both genotypes developed longer root hair under P deficit. ZD958 (greater biomass and shoot P content) has a greater capability at accessing soil P than XY335. Rhizosphere exudation of citric acid was significantly higher in ZD958 than in XY335, while there was not significant genotypic difference in rhizosphere pH and exudation of malic acid and acid phosphatase activity. ZD958 had higher P uptake rate than XY335 when solution P was between 12.5 and 250 µM. This study identified ZD958 as a P-efficient genotype, which better adapted to low P stress by altering root physiological traits (exudation of citric acid and P uptake rate), rather than root morphological traits (total root length, root surface area, root hair length). Our results highlight the importance of analyzing root morphological and physiological traits to enhance our understanding of the physiological mechanisms of P acquisition.

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Root morphological characteristics of host species having distinct mycorrhizal dependency

Canadian Journal of Botany ◽

10.1139/b91-089 ◽

1991 ◽

Vol 69 (3) ◽

pp. 671-676 ◽

Cited By ~ 50

Author(s):

A. Manjunath ◽

M. Habte

Keyword(s):

Root Hair ◽

Morphological Characteristics ◽

Root Surface ◽

P Uptake ◽

Root Diameter ◽

Root Surface Area ◽

Root Mass ◽

Hair Length ◽

Mycorrhizal Dependency ◽

Root Characteristics

Greenhouse and growth chamber investigations were undertaken using selected Leucaena and Sesbania species to determine the extent to which root morphological characteristics and rhizosphere acid production could explain differences in mycorrhizal dependency of host plants. Compared with the moderately to very highly mycorrhizal-dependent Leucaena species, the marginally to moderately dependent Sesbania species were characterized by higher root mass, higher root density, higher root surface area, higher root length, smaller root diameter, higher percentage of root hair incidence, higher shoot to root ratio, and higher total P uptake. The two groups of species were not consistently different from each other with respect to mycorrhizal colonization level, root hair diameter, root hair length, P uptake per unit root surface area, and acid production in agar media. A stepwise regression model in which mycorrhizal dependency (MD) was used as the dependent variable and root characteristics as independent variables suggested that root mass, root hair length, root diameter, root density, and root hair incidence were important determinants of MD, with root mass accounting for 65.5% of the variability. The results suggest that differences in the mycorrhizal dependency of host species can be largely predicted from root characteristics data. Key words: Brassica, Leucaena, Sesbania, P uptake, root hair, root mass.

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Potassium translocation combined with specific root uptake is responsible for the high potassium efficiency in vegetable soybean

Crop and Pasture Science ◽

10.1071/cp19042 ◽

2019 ◽

Vol 70 (6) ◽

pp. 516 ◽

Cited By ~ 2

Author(s):

Changkai Liu ◽

Bingjie Tu ◽

Xue Wang ◽

Jian Jin ◽

Yansheng Li ◽

...

Keyword(s):

Uptake Rate ◽

Root Length ◽

Root Surface ◽

Root Surface Area ◽

Total Root Length ◽

Vegetable Soybean ◽

K Uptake ◽

High Potassium ◽

Source To Sink ◽

Low K

Uptake of potassium (K) in crops depends mainly on the root system. Field, pot and hydroponic experiments were carried out to characterise root morphological traits and examine their roles in K uptake and utilisation of vegetable soybean (edamame) (Glycine max (L.) Merr.). Of 40 genotypes, two high K-efficiency (HKE) and two low K-efficiency (LKE) genotypes were identified and compared at two levels of K application: nil or 120 kg K2SO4 ha–1. HKE genotypes had shorter total root length and smaller root surface area and root volume than LKE genotypes, but responded earlier to low-K conditions by adjusting root architecture. In plants receiving nil K, total root length was increased by 10.4–21.8% for HKE genotypes but decreased by 5.5–9.5% for LKE genotypes at the V4 stage relative to plants receiving applied K. HKE genotypes were more efficient in redistributing K from source to sink tissue, especially from leaf. Of the total K in vegetative tissues, 35.0–46.4% was redistributed to seed in HKE genotypes, whereas only 19.7–28.2% was redistributed in LKE genotypes. HKE genotypes also had a higher specific K uptake rate (K uptake per unit root length), 1.6–1.7 times higher than LKE genotypes at the R5 stage. This indirectly indicated a stronger root K acquisition in HKE genotypes. This study suggests that future vegetable soybean improvement with greater K efficiency should be focused on the selection of higher K-redistribution rate and specific K-uptake rate.

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Comparison of Root System Morphology of Cucurbit Rootstocks for Use in Watermelon Grafting

HortTechnology ◽

10.21273/horttech04098-18 ◽

2018 ◽

Vol 28 (5) ◽

pp. 629-636 ◽

Cited By ~ 4

Author(s):

Matthew B. Bertucci ◽

David H. Suchoff ◽

Katherine M. Jennings ◽

David W. Monks ◽

Christopher C. Gunter ◽

...

Keyword(s):

Root System ◽

Surface Area ◽

Root Length ◽

Dry Weight ◽

Root Systems ◽

Root Surface ◽

Root Diameter ◽

Root Surface Area ◽

Diameter Class ◽

Main Effect

Grafting of watermelon (Citrullus lanatus) is an established production practice that provides resistance to soilborne diseases or tolerance to abiotic stresses. Watermelon may be grafted on several cucurbit species (interspecific grafting); however, little research exists to describe root systems of these diverse rootstocks. A greenhouse study was conducted to compare root system morphology of nine commercially available cucurbit rootstocks, representing four species: pumpkin (Cucurbita maxima), squash (Cucurbita pepo), bottle gourd (Lagenaria siceraria), and an interspecific hybrid squash (C. maxima × C. moschata). Rootstocks were grafted with a triploid watermelon scion (‘Exclamation’), and root systems were compared with nongrafted (NG) and self-grafted (SG) ‘Exclamation’. Plants were harvested destructively at 1, 2, and 3 weeks after transplant (WAT), and data were collected on scion dry weight, total root length (TRL), average root diameter, root surface area, root:shoot dry-weight ratio, root diameter class proportions, and specific root length. For all response variables, the main effect of rootstock and rootstock species was significant (P < 0.05). The main effect of harvest was significant (P < 0.05) for all response variables, with the exception of TRL proportion in diameter class 2. ‘Ferro’ rootstock produced the largest TRL and root surface area, with observed values 122% and 120% greater than the smallest root system (‘Exclamation’ SG), respectively. Among rootstock species, pumpkin produced the largest TRL and root surface area, with observed values 100% and 82% greater than those of watermelon, respectively. These results demonstrate that substantial differences exist during the initial 3 WAT in root system morphology of rootstocks and rootstock species available for watermelon grafting and that morphologic differences of root systems can be characterized using image analysis.

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Study on measurement method for apple root morphological parameters based on Labview

Plant Methods ◽

10.1186/s13007-019-0535-4 ◽

2019 ◽

Vol 15 (1) ◽

Cited By ~ 1

Author(s):

Yu Liu ◽

Ji Qian ◽

Xin Yang ◽

Bao Di ◽

Juan Zhou

Keyword(s):

Root System ◽

Surface Area ◽

Relative Error ◽

Root Length ◽

Average Diameter ◽

Root Surface ◽

Root Diameter ◽

Root Surface Area ◽

Root Volume ◽

Seedling Roots

Abstract Background Traditional measurements of apple seedling roots often rely on manual measurements and existing root scanners on the market. Manual measurement requires a lot of labor and time, and subjective reasons may cause the uncertainty of data; root scanners have limited scanning size and expensive. In case of fruit roots, coverage and occlusion issues will occur, resulting in inaccurate results, but our research solved this problem. Results The background plate was selected according to the color of the seedling roots; the image of the roots of the collected apple seedlings was preprocessed with Vision Development Module by combining image and Labview. The root surface area, average root diameter, root length and root volume of apple seedlings were measured by combining root characteristic parameters algorithm. In order to verify the effectiveness of the proposed method, a set of measurement system for root morphology of apple seedlings was designed, and the measurement result was compared with the Canadian root system WinRHIZO 2016 (Canada). With application of SPSS v22.0 analysis, the significance P > 0.01 indicated that the difference was not significant. The relative error of surface area was less than 0.5%. The relative error of the average diameter and length of the root system was less than 0.1%, and the relative error of the root volume was less than 0.2%. Conclusions It not only proved that the root surface area, average root diameter, root length and root volume of apple seedlings could be accurately measured by the method described herein, which was handy in operation, but also reduced the cost by 80–90% compared with the conventional scanner.

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Stand morphology of Townsville lucerne (Stylosanthes humilis) : Seasonal growth and root development

Australian Journal of Experimental Agriculture ◽

10.1071/ea9680533 ◽

1968 ◽

Vol 8 (34) ◽

pp. 533 ◽

Cited By ~ 19

Author(s):

BWR Torssell ◽

JE Begg ◽

CW Rose ◽

GF Byrne

Keyword(s):

Root Length ◽

Lateral Roots ◽

Heavy Rain ◽

Root Surface ◽

Root Surface Area ◽

General Description ◽

Seasonal Growth ◽

Wet Season ◽

Average Growth ◽

Stylosanthes Humilis

This paper describes the seasonal growth and morphology of a four-year-old pasture of Townsville lucerne (Stylosanthes humilis) used in a detailed microenvironmental study conducted at Katherine, N.T., during the 1966-67 wet season. Rapid germination and penetration of the tap root followed an early storm rain of 38 mm at the end of September, and most of the seedlings survived the next seven weeks without rain. A second germination followed heavy rain at the end of November, and by the end of December the main development of lateral roots commenced and the rate of shoot development increased. The highest average growth rate, 31 g/m2/day for the period March 31-April 14, was after the last rain of the season and preceded by ten weeks of above average rainfall. Growth continued for a further two weeks while the roots continued to deplete available soil water. During the main period of growth, approximately 80 per cent of root length and 70 per cent of root surface area was in the top 30 cm of soil. The density of root length varied very little below 30 cm. Growth and development are discussed in relation to grass competition and drought adaptation, and fitted to a general description of the life cycle of Townsville lucerne under northern Australian conditions.

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Phosphorus Uptake and Utilization Efficiency in Peanut1

Peanut Science ◽

10.3146/i0095-3679-24-1-1 ◽

1997 ◽

Vol 24 (1) ◽

pp. 1-6 ◽

Cited By ~ 2

Author(s):

K. R. Krishna

Keyword(s):

Root Length ◽

Phosphorus Uptake ◽

P Uptake ◽

Utilization Efficiency ◽

P Efficiency ◽

Efficiency Ratio ◽

Soil P ◽

Arachis Hypogaea L ◽

P Accumulation ◽

Total P

Abstract Cultivars of a crop can differ genetically with respect to their uptake, translocation, accumulation, and use of phosphorus. The objective of this paper was to evaluate genetic variation for P uptake and utilization among peanut (Arachis hypogaea L.) genotypes. Several traits contribute to the total P efficiency of the genotype, including root length, rate of P uptake per unit root length, leaf and pod characters such as P accumulation, and dry matter/yield produced per unit P absorbed [i.e., P efficiency ratio (PER)]. Peanut genotypes with increased P uptake and higher PER were identified. Some genotypes sustained higher PER at both low and high soil P availabilities.

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Root hair specification and its growth in response to nutrients

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha49212258 ◽

2021 ◽

Vol 49 (2) ◽

pp. 12258

Author(s):

Xian HUANG ◽

Tianzhi GONG ◽

Mei LI ◽

Cenghong HU ◽

Dejian ZHANG ◽

...

Keyword(s):

Root Hair ◽

Reverse Genetics ◽

Current Knowledge ◽

Plant Root ◽

Root Hairs ◽

Root Surface ◽

Root Surface Area ◽

Root Hair Development ◽

Hair Development ◽

Calcium Iron

Plant root hairs are cylindrical tubular projections from root epidermal cells. They increase the root surface area, which is important for the acquisition of water and nutrients, microbe interactions, and plant anchorage. The root hair specification, the effect of root hairs on nutrient acquisition and the mechanisms of nutrients (calcium, iron, magnesium, nitrogen, phosphorus, and potassium) that affect root hair development and growth were reviewed. The gene regulatory network on root hair specification in the plant kingdom was highlighted. More work is needed to clone the genes of additional root hair mutants and elucidate their roles, as well as undertaking reverse genetics and mutant complementation studies to add to the current knowledge of the signaling networks, which are involved in root hair development and growth regulated by nutrients.

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Determination of root properties of saplings belong to two boxwood species (Buxus sempervirens and Buxus balearica) by image processing technique

Turkish Journal of Food and Agriculture Sciences ◽

10.14744/turkjfas.2021.005 ◽

2021 ◽

pp. 20-24

Author(s):

Ömer Sarı

Keyword(s):

Surface Area ◽

Root Length ◽

Root Surface ◽

Root Diameter ◽

Image Processing Technique ◽

Root Surface Area ◽

Root Tips ◽

Root Volume ◽

Buxus Sempervirens ◽

Second Year

The study was carried out to determine the root architectural characteristics of the one-year saplings of two species of boxwood (Buxus sempervirens L. and Buxus balearica Lam.), which are endangered and natural plants of Turkey, in the greenhouse environment using the WinRhizo root analysis program and scanner. Total root length (cm), root surface area (cm2), root volume (cm3), average root diameter (mm), number of tips, number of forks and number of root crossings were determined in the study. According to the results of the study, the increase in temperature and decrease in humidity values in the second year of both species were effective on the root architectural features. As a result of this effect, the second year root length (3810 cm), number of root tips (2299), number of forks (7007) and number of root crossings (696) increased, root diameter (1.4 mm), root surface area (2158 cm2) and root volume (8 cm3) decreased. As a result, it has been concluded that species can make changes in their root parameters to adapt to different conditions and their adaptability is high. In general, the best results in root architectural parameters were obtained from Buxus balearica on the basis of species.

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Significance of root hairs at the field scale – modelling root water and phosphorus uptake under different field conditions

Plant and Soil ◽

10.1007/s11104-019-04308-2 ◽

2019 ◽

Vol 447 (1-2) ◽

pp. 281-304 ◽

Cited By ~ 3

Author(s):

S. Ruiz ◽

N. Koebernick ◽

S. Duncan ◽

D. McKay Fletcher ◽

C. Scotson ◽

...

Keyword(s):

Uptake Rate ◽

Large Scale ◽

Phosphorus Uptake ◽

Root Hairs ◽

P Uptake ◽

Growth Stages ◽

Field Scale ◽

Soil P ◽

Simulation Results ◽

The Impact

Abstract Background and aims Root hairs play a significant role in phosphorus (P) extraction at the pore scale. However, their importance at the field scale remains poorly understood. Methods This study uses a continuum model to explore the impact of root hairs on the large-scale uptake of P, comparing root hair influence under different agricultural scenarios. High vs low and constant vs decaying P concentrations down the soil profile are considered, along with early vs late precipitation scenarios. Results Simulation results suggest root hairs accounted for 50% of total P uptake by plants. Furthermore, a delayed initiation time of precipitation potentially limits the P uptake rate by over 50% depending on the growth period. Despite the large differences in the uptake rate, changes in the soil P concentration in the domain due to root solute uptake remains marginal when considering a single growth season. However, over the duration of 6 years, simulation results showed that noticeable differences arise over time. Conclusion Root hairs are critical to P capture, with uptake efficiency potentially enhanced by coordinating irrigation with P application during earlier growth stages of crops.

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Integrating GWAS and Gene Expression Analysis Identifies Candidate Genes for Root Morphology Traits in Maize at the Seedling Stage

Genes ◽

10.3390/genes10100773 ◽

2019 ◽

Vol 10 (10) ◽

pp. 773 ◽

Cited By ~ 1

Author(s):

Wang ◽

Wei ◽

Li ◽

Wang ◽

Ge ◽

...

Keyword(s):

Root System ◽

Candidate Genes ◽

Root Development ◽

Root Length ◽

Root Traits ◽

Root Surface ◽

Root Surface Area ◽

Phenotypic Variance ◽

Potential Candidate ◽

Short Root

Root system plays an essential role in water and nutrient acquisition in plants. Understanding the genetic basis of root development will be beneficial for breeding new cultivars with efficient root system to enhance resource use efficiency in maize. Here, the natural variation of 13 root and 3 shoot traits was evaluated in 297 maize inbred lines and genome-wide association mapping was conducted to identify SNPs associated with target traits. All measured traits exhibited 2.02- to 21.36-fold variations. A total of 34 quantitative trait loci (QTLs) were detected for 13 traits, and each individual QTL explained 5.7% to 15.9% of the phenotypic variance. Three pleiotropic QTLs involving five root traits were identified; SNP_2_104416607 was associated with lateral root length (LRL), root surface area (RA), root length between 0 and 0.5mm in diameter (RL005), and total root length (TRL); SNP_2_184016997 was associated with RV and RA, and SNP_4_168917747 was associated with LRL, RA and TRL. The expression levels of candidate genes in root QTLs were evaluated by RNA-seq among three long-root lines and three short-root lines. A total of five genes that showed differential expression between the long- and short-root lines were identified as promising candidate genes for the target traits. These QTLs and the potential candidate genes are important source data to understand root development and genetic improvement of root traits in maize.

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