scholarly journals Root engineering in maize by increasing cytokinin degradation causes enhanced root growth and leaf mineral enrichment

2021 ◽  
Author(s):  
Eswarayya Ramireddy ◽  
Hilde Nelissen ◽  
Jan Erik Leuendorf ◽  
Mieke Van Lijsebettens ◽  
Dirk Inzé ◽  
...  
Keyword(s):  
Root Growth ◽  
Root System ◽  
Dry Weight ◽  
Negative Regulator ◽  
Cytokinin Oxidase ◽  
Specific Expression ◽  
Genetically Engineer ◽  
Transgenic Lines ◽  
Access To Water ◽  
Specific Degradation

Abstract Key message Root-specific expression of a cytokinin-degrading CKX gene in maize roots causes formation of a larger root system leading to higher element content in shoot organs. Abstract The size and architecture of the root system is functionally relevant for the access to water and soil nutrients. A great number of mostly unknown genes are involved in regulating root architecture complicating targeted breeding of plants with a larger root system. Here, we have explored whether root-specific degradation of the hormone cytokinin, which is a negative regulator of root growth, can be used to genetically engineer maize (Zea mays L.) plants with a larger root system. Root-specific expression of a CYTOKININ OXIDASE/DEHYDROGENASE (CKX) gene of Arabidopsis caused the formation of up to 46% more root dry weight while shoot growth of these transgenic lines was similar as in non-transgenic control plants. The concentration of several elements, in particular of those with low soil mobility (K, P, Mo, Zn), was increased in leaves of transgenic lines. In kernels, the changes in concentration of most elements were less pronounced, but the concentrations of Cu, Mn and Zn were significantly increased in at least one of the three independent lines. Our data illustrate the potential of an increased root system as part of efforts towards achieving biofortification. Taken together, this work has shown that root-specific expression of a CKX gene can be used to engineer the root system of maize and alter shoot element composition.

scholarly journals Longleaf Pine Root System Development and Seedling Quality in Response to Copper Root Pruning and Cavity Size

2011 ◽  
Vol 35 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Mary Anne Sword Sayer ◽  
Shi-Jean Susana Sung ◽  
James D. Haywood
Keyword(s):  
Root Growth ◽  
Root System ◽  
System Development ◽  
Longleaf Pine ◽  
Lateral Roots ◽  
Dry Weight ◽  
Root Pruning ◽  
Cavity Size ◽  
Root System Development ◽  
Primary Lateral

Abstract Cultural practices that modify root system structure in the plug of container-grown seedlings have the potential to improve root system function after planting. Our objective was to assess how copper root pruning affects the quality and root system development of longleaf pine seedlings grown in three cavity sizes in a greenhouse. Copper root pruning increased seedling size, the allocation of root system dry weight to the taproot, and the fraction of fibrous root mass allocated to secondary lateral roots compared with primary lateral roots. It decreased the allocation of root system dry weight to primary lateral roots and led to a distribution of root growth potential that more closely resembled the root growth of naturally sown seedlings. These effects of copper root pruning may benefit longleaf pine establishment. However, because copper root pruning increased competition for cavity growing space among the taproot and fibrous roots, we suggest that recommendations regarding cavity size and seedling quality parameters be tailored for copper-coated cavities.

Responses of Pinushalepensis seedlings to flooding

1980 ◽  
Vol 10 (3) ◽  
pp. 308-311 ◽  
Author(s):  
A. R. Sena Gomes ◽  
T. T. Kozlowski
Keyword(s):  
Root Growth ◽  
Root System ◽  
Dry Weight ◽  
Inhibitory Effects ◽  
Weight Increment ◽  
Soil Inundation

Pinushalepensis Mill, seedlings adapted poorly to flooding. Soil inundation up to 40 days induced stem swelling and splitting and inhibited dry weight increment of seedlings. Flooding decreased dry weight increment of shoots, largely by inhibiting formation of secondary needles. However, flooding had much greater inhibitory effects on root growth. Flooding inhibited root growth almost completely and also caused some deterioration of the original root system.

scholarly journals 592 PB 164 POST-TRANSPLANT ROOT GROWTH OF CITRUS PLANTS AS INFLUENCED BY PRODUCTION TIME IN NURSERY CONTAINERS

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 516f-516
Author(s):  
Thomas E. Marler
Keyword(s):  
Methylene Blue ◽  
Root Growth ◽  
Root System ◽  
Nutrient Solution ◽  
Dry Weight ◽  
Two Dimensional ◽  
Rooted Cuttings ◽  
Post Transplant ◽  
Root Regeneration ◽  
Complete Nutrient Solution

An aeroponics system was used to determine root growth of Citrus aurantifolia Swingle following removal from containers. Rooted cuttings were planted in 0.46-liter containers in a 1 sand: 1 perlite medium, and watered daily and fertilized with a complete nutrient solution weekly. The plants were grown in the containers until root growth had filled the container volume. A sample of plants was removed from the bench after 86, 146, or 210 days in container production. Plants were bare-rooted and the existing root system dyed with methylene blue, and placed in the aeroponics system. The plants were maintained in the aeroponics system for 50 days, then were harvested and the roots separated into pre-existing roots and new roots. Two dimensional area and dry weight of roots were measured. Relative new root growth of plants that were maintained 210 days in the containers was less than that of plants that were removed from containers earlier. The data indicate that maintaining plants in containers for extended periods of time may reduce root regeneration following removal from containers.

Water relations of winter wheat: 1. Growth of the root system

1978 ◽  
Vol 91 (1) ◽  
pp. 91-102 ◽  
Author(s):  
P. J. Gregory ◽  
M. McGowan ◽  
P. V. Biscoe ◽  
B. Hunter
Keyword(s):  
Winter Wheat ◽  
Root Growth ◽  
Root System ◽  
Water Relations ◽  
Root Length ◽  
Dry Weight ◽  
Growing Season ◽  
Main Stem ◽  
Soil Cores ◽  
Root Dry Weight

SummaryThe production of root axes and the growth of the root system are reported for a commercially grown crop of Maris Huntsman winter wheat. Soil cores were extracted on 17 occasions during the growing season permitting a detailed study of root length and root dry weight with depth and time.Production of seminal root axes was complete by the beginning of March when all plants possessed six (occasionally seven) axes which persisted throughout the life of the crop. Nodal axes were produced continuously from mid-February until late May and finally numbered approximately 20 stem nodal axes per main stem. Total root dry weight increased exponentially until the beginning of April and then almost linearly to reach a maximum of 105 g root/m2 field in mid-June (anthesis). After anthesis, total root dry weight decreased but root growth continued below 80 cm. From April onwards, approximately 65% of the total root dry weight was in the 0–30 cm layer.

scholarly journals Root‐specific expression of chickpea cytokinin oxidase/dehydrogenase 6 leads to enhanced root growth, drought tolerance and yield without compromising nodulation

2020 ◽  
Vol 18 (11) ◽  
pp. 2225-2240 ◽  
Author(s):  
Hitaishi Khandal ◽  
Santosh Kumar Gupta ◽  
Vikas Dwivedi ◽  
Drishti Mandal ◽  
Nilesh Kumar Sharma ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Root Growth ◽  
Cytokinin Oxidase ◽  
Specific Expression

Effects of NaCl treatment on root system activity of the euhalophyte Aksora

2021 ◽  
pp. 46-55
Author(s):  
Zh. Rakhymzhan ◽  
Zh.B. Tekebayeva ◽  
R.R. Beysenova ◽  
A.D. Rakhisheva
Keyword(s):  
Root Growth ◽  
Root System ◽  
Surface Area ◽  
Root Length ◽  
Dry Weight ◽  
Suaeda Salsa ◽  
Total Root Length ◽  
Fresh Weight ◽  
Total Length ◽  
Absorption Area

For the purpose of study the relationship between the characteristics of the root system, activity and saline pressure of Aksora (Suaeda salsa Pall.) various concentrations of NaCl (0, 200, 400 and 600 mmol/L) were prepared. The effect of salt concentration on the biomass of Aksora (Suaeda salsa Pall.) root and the activity of the root system was studied. The results showed that as the NaCl concentration increased, the dry and fresh weight of the Aksora (Suaeda salsa Pall.) roots, the total length and surface area of the root increased and then gradually decreased. The highest values of dry weight, fresh weight and total length of the vascular system were observed at a concentration of 200 mmol / L NaCl, while at a concentration of 600 mmol/L NaCl, the dry weight, wet weight and total root length, and surface area signifi cantly decreased. These results indicate that refi nement of Aksora with higher concentrations of NaCl salt can increase the total length and absorption area of roots, thereby promoting root growth and adaptability to saline pressure. However, it has been found that with extrmely high salt concentrations inhibit root growth by reducing the total root length and absorption area. Key words: Aksora, vascular activity, NaCl, absorption zone.

scholarly journals Root Distribution of `Gulfcoast' Southern Highbush Blueberry

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 428A-428
Author(s):  
J.M. Spiers
Keyword(s):  
Soil Moisture ◽  
Root Growth ◽  
Root System ◽  
Root Distribution ◽  
System Development ◽  
Dry Weight ◽  
Highbush Blueberry ◽  
Root System Development ◽  
Highbush Blueberries ◽  
Southern Highbush

A field study was conducted to evaluate individual and collective influences of three soil moisture-supplementing practices (irrigation, incorporated peatmoss, and mulching) on root system development in `Gulfcoast' southern highbush blueberries. Root growth was least in plants not mulched and greatest in plants receiving all three supplements. Ranking of individual treatments on root dry weight production was mulch > incorporated peatmoss = irrigation. Mulching resulted in uniform root distribution from the plant crown outward and in root growth concentrated in the upper 15 cm of soil. Other practices (peatmoss > irrigation) tended to concentrate the root system near the crown area and resulted (peatmoss = irrigation) in greater root depth. Soil moisture appeared to be the major factor influencing root distribution.

Genetic variation for rate of establishment in caucasian clover

1998 ◽  
pp. 213-217
Author(s):  
K.H. Widdup ◽  
T.L. Knight ◽  
C.J. Waters
Keyword(s):  
Genetic Variation ◽  
Root Growth ◽  
Seedling Growth ◽  
White Clover ◽  
Seedling Emergence ◽  
Red Clover ◽  
Dry Weight ◽  
Cool Season ◽  
Trifolium Ambiguum ◽  
Root Dry Weight

Slow establishment of caucasian clover (Trifolium ambiguum L.) is hindering the use of this legume in pasture mixtures. Improved genetic material is one strategy of correcting the problem. Newly harvested seed of hexaploid caucasian clover germplasm covering a range of origins, together with white and red clover and lucerne, were sown in 1 m rows in a Wakanui soil at Lincoln in November 1995. After 21 days, the caucasian clover material as a group had similar numbers of emerged seedlings as white clover and lucerne, but was inferior to red clover. There was wide variation among caucasian clover lines (48-70% seedling emergence), with the cool-season selection from cv. Monaro ranked the highest. Recurrent selection at low temperatures could be used to select material with improved rates of seedling emergence. Red clover and lucerne seedlings produced significantly greater shoot and root dry weight than caucasian and white clover seedlings. Initially, caucasian clover seedlings partitioned 1:1 shoot to root dry weight compared with 3:1 for white clover. After 2 months, caucasian clover seedlings had similar shoot growth but 3 times the root growth of white clover. Between 2 and 5 months, caucasian clover partitioned more to root and rhizome growth, resulting in a 0.3:1 shoot:root ratio compared with 2:1 for white clover. Both clover species had similar total dry weight after 5 months. Unhindered root/ rhizome devel-opment is very important to hasten the establishment phase of caucasian clover. The caucasian clover lines KZ3 and cool-season, both selections from Monaro, developed seedlings with greater shoot and root growth than cv. Monaro. KZ3 continued to produce greater root growth after 5 months, indicating the genetic potential for improvement in seedling growth rate. Different pasture estab-lishment techniques are proposed that take account of the seedling growth characteristics of caucasian clover. Keywords: establishment, genetic variation, growth, seedling emergence, Trifolium ambiguum

scholarly journals Overexpression of vesicle-associated membrane protein PttVAP27-17 as a tool to improve biomass production and the overall saccharification yields in Populus trees

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Madhavi Latha Gandla ◽  
Niklas Mähler ◽  
Sacha Escamez ◽  
Tomas Skotare ◽  
Ogonna Obudulu ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Biomass Production ◽  
Enzymatic Saccharification ◽  
Dry Weight ◽  
Populus Tremula ◽  
Transgenic Trees ◽  
Wild Type ◽  
Glucose Yield ◽  
Transgenic Lines ◽  
Wild Type Control

Abstract Background Bioconversion of wood into bioproducts and biofuels is hindered by the recalcitrance of woody raw material to bioprocesses such as enzymatic saccharification. Targeted modification of the chemical composition of the feedstock can improve saccharification but this gain is often abrogated by concomitant reduction in tree growth. Results In this study, we report on transgenic hybrid aspen (Populus tremula × tremuloides) lines that showed potential to increase biomass production both in the greenhouse and after 5 years of growth in the field. The transgenic lines carried an overexpression construct for Populus tremula × tremuloides vesicle-associated membrane protein (VAMP)-associated protein PttVAP27-17 that was selected from a gene-mining program for novel regulators of wood formation. Analytical-scale enzymatic saccharification without any pretreatment revealed for all greenhouse-grown transgenic lines, compared to the wild type, a 20–44% increase in the glucose yield per dry weight after enzymatic saccharification, even though it was statistically significant only for one line. The glucose yield after enzymatic saccharification with a prior hydrothermal pretreatment step with sulfuric acid was not increased in the greenhouse-grown transgenic trees on a dry-weight basis, but increased by 26–50% when calculated on a whole biomass basis in comparison to the wild-type control. Tendencies to increased glucose yields by up to 24% were present on a whole tree biomass basis after acidic pretreatment and enzymatic saccharification also in the transgenic trees grown for 5 years on the field when compared to the wild-type control. Conclusions The results demonstrate the usefulness of gene-mining programs to identify novel genes with the potential to improve biofuel production in tree biotechnology programs. Furthermore, multi-omic analyses, including transcriptomic, proteomic and metabolomic analyses, performed here provide a toolbox for future studies on the function of VAP27 proteins in plants.

scholarly journals Genome-wide association analysis unveils novel QTLs for seminal root system architecture traits in Ethiopian durum wheat

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Admas Alemu ◽  
Tileye Feyissa ◽  
Marco Maccaferri ◽  
Giuseppe Sciara ◽  
Roberto Tuberosa ◽  
...  
Keyword(s):  
Durum Wheat ◽  
Root System ◽  
System Architecture ◽  
Root Length ◽  
Dry Weight ◽  
Root System Architecture ◽  
High Density ◽  
Soil Conditions ◽  
Root Dry Weight ◽  
Seminal Roots

Abstract Background Genetic improvement of root system architecture is essential to improve water and nutrient use efficiency of crops or to boost their productivity under stress or non-optimal soil conditions. One hundred ninety-two Ethiopian durum wheat accessions comprising 167 historical landraces and 25 modern cultivars were assembled for GWAS analysis to identify QTLs for root system architecture (RSA) traits and genotyped with a high-density 90 K wheat SNP array by Illumina. Results Using a non-roll, paper-based root phenotyping platform, a total of 2880 seedlings and 14,947 seminal roots were measured at the three-leaf stage to collect data for total root length (TRL), total root number (TRN), root growth angle (RGA), average root length (ARL), bulk root dry weight (RDW), individual root dry weight (IRW), bulk shoot dry weight (SDW), presence of six seminal roots per seedling (RT6) and root shoot ratio (RSR). Analysis of variance revealed highly significant differences between accessions for all RSA traits. Four major (− log10P ≥ 4) and 34 nominal (− log10P ≥ 3) QTLs were identified and grouped in 16 RSA QTL clusters across chromosomes. A higher number of significant RSA QTL were identified on chromosome 4B particularly for root vigor traits (root length, number and/or weight). Conclusions After projecting the identified QTLs on to a high-density tetraploid consensus map along with previously reported RSA QTL in both durum and bread wheat, fourteen nominal QTLs were found to be novel and could potentially be used to tailor RSA in elite lines. The major RGA QTLs on chromosome 6AL detected in the current study and reported in previous studies is a good candidate for cloning the causative underlining sequence and identifying the beneficial haplotypes able to positively affect yield under water- or nutrient-limited conditions.

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