Distribution and variation of hydroxamic acids and related compounds in maize (Zea mays) root system

1991 ◽  
Vol 69 (3) ◽  
pp. 677-681 ◽  
Author(s):  
Y. S. Xie ◽  
J. T. Arnason ◽  
B. J. R. Philogène ◽  
J. Atkinson ◽  
P. Morand
Keyword(s):  
Root System ◽  
High Performance ◽  
Primary Root ◽  
Hydroxamic Acids ◽  
Maize Root ◽  
Root Extracts ◽  
Nodal Roots ◽  
Maize Varieties ◽  
Maize Roots ◽  
Related Compounds

The concentrations of hydroxamic acids and related compounds, 2, 4-dihydroxy-7,8-dimethoxy-1,4-benzoxazin-3(4H)-one (DIM2BOA), 2-hydroxy-7,8-dimethoxy-1,4-benzoxazin-3(4H)-one (HMBOA), 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3(4H)-one (DIMBOA), and 6-methoxybenzoxazolinone (MBOA), in roots of 1- to 5-week-old maize plants were determined by high-performance liquid chromatography (HPLC). The highest concentrations of DIM2BOA, HMBOA, and total related compounds were found in maize root extracts when maize roots were 2 weeks old and the maize plant was approximately 15 cm in height. The highest concentrations of DIMBOA equivalents were found in 4-week-old maize root extracts. The distribution of individual compounds in different tissues (cortex, stele, and complete organ) of various root parts (first set of nodal roots, secondary roots, primary root, mesocotyl, and adventitious roots from mesocotyl) was also determined. Hydroxamic acids and related compounds are concentrated in the cortex of all parts of maize roots determined except mesocotyl. The concentrations of total related compounds and all individual compounds except HMBOA in complete organ of nodal roots were significantly higher than any other parts of maize roots. The high concentrations of these substances in the cortex of maize root may be relevant in the resistance of maize varieties to subterranean pest insects. Key words: hydroxamic acids, 1,4-benzoxazin-3-ones, maize, root system.

Hydroxamic acid content in maize (Zea mays) roots of 18 Ontario recommended hybrids and prediction of antibiosis to the western corn rootworm, Diabrotica virgifera virgifera LeConte [Coleoptera: Chrysomelidae]

1993 ◽  
Vol 73 (1) ◽  
pp. 359-363 ◽  
Author(s):  
R. A. Assabgui ◽  
J. T. Arnason ◽  
R. I. Hamilton
Keyword(s):  
Hydroxamic Acid ◽  
High Performance ◽  
Diabrotica Virgifera Virgifera ◽  
Hydroxamic Acids ◽  
Western Corn Rootworm ◽  
Corn Rootworm ◽  
Diabrotica Virgifera ◽  
Maize Hybrids ◽  
Root Extracts ◽  
Diabrotica Virgifera Virgifera Leconte

High performance liquid chromatography was used to assess concentrations of hydroxamic acids in maize root extracts of 18 greenhouse-grown hybrids recommended in Ontario. On the basis of hydroxamic acid concentrations, low-level antibiosis against the western corn rootworm, Diabrotica virgifera virgifera LeConte was predicted for the majority of these (1990) hybrids, when grown under field conditions. Key words: Antibiosis, Chrysomelidae, Diabrotica, DIMBOA, hydroxamic acids, maize hybrids

scholarly journals TopoRoot: A method for computing hierarchy and fine-grained traits of maize roots from X-ray CT images

2021 ◽  
Author(s):  
Dan Zeng ◽  
Mao Li ◽  
Ni Jiang ◽  
Yiwen Ju ◽  
Hannah Schreiber ◽  
...  
Keyword(s):  
Root System ◽  
System Architecture ◽  
State Of The Art ◽  
Root System Architecture ◽  
Ct Images ◽  
Maize Root ◽  
Root Number ◽  
X Ray ◽  
Fine Grained ◽  
Maize Roots

Background: 3D imaging, such as X-ray CT and MRI, has been widely deployed to study plant root structures. Many computational tools exist to extract coarse-grained features from 3D root images, such as total volume, root number and total root length. However, methods that can accurately and efficiently compute fine-grained root traits, such as root number and geometry at each hierarchy level, are still lacking. These traits would allow biologists to gain deeper insights into the root system architecture (RSA). Results: We present TopoRoot, a high-throughput computational method that computes fine-grained architectural traits from 3D X-ray CT images of field-excavated maize root crowns. These traits include the number, length, thickness, angle, tortuosity, and number of children for the roots at each level of the hierarchy. TopoRoot combines state-of-the-art algorithms in computer graphics, such as topological simplification and geometric skeletonization, with customized heuristics for robustly obtaining the branching structure and hierarchical information. TopoRoot is validated on both real and simulated root images, and in both cases it was shown to improve the accuracy of traits over existing methods. We also demonstrate TopoRoot in differentiating a maize root mutant from its wild type segregant using fine-grained traits. TopoRoot runs within a few minutes on a desktop workstation for volumes at the resolution range of 400^3, without need for human intervention. Conclusions: TopoRoot improves the state-of-the-art methods in obtaining more accurate and comprehensive fine-grained traits of maize roots from 3D CT images. The automation and efficiency makes TopoRoot suitable for batch processing on a large number of root images. Our method is thus useful for phenomic studies aimed at finding the genetic basis behind root system architecture and the subsequent development of more productive crops.

The nodal roots of Zea: their development in relation to structural features of the stem

1986 ◽  
Vol 64 (11) ◽  
pp. 2524-2537 ◽  
Author(s):  
D. C. Hoppe ◽  
M. E. McCully ◽  
C. L. Wenzel
Keyword(s):  
Root System ◽  
Primary Root ◽  
Ground Level ◽  
Structural Features ◽  
Nodal Roots ◽  
Extensive Region ◽  
Nodal Root ◽  
The Mean ◽  
Xylem Conduits

The framework of the root system of a mature, field-grown corn plant of variety Seneca Chief consists of about 70 axile roots. One of these is the primary root. The others develop on the stem, a single tier at each of the seven basal nodes. Just over half of these roots grow out at or above ground level from nodes 6 and 7 late in the development of the plant, with those of node 7 entering the soil just before flowering. The mean diameter of the root produced at successively higher nodes increases, as does also the mean number of large metaxylem elements seen in a cross section, so that about 75% of the large xylem conduits between the root system and the stem are in the roots of the two uppermost tiers. Nodal root primordia develop initially in situ from an extensive region of dedifferentiated stem cortex. A sleeve-like extension of the stem encloses the base of each root formed at aerial nodes. At each node the complexity of vascular interconnections results in all of the framework roots being indirectly linked to each other and to the vascular traces from all of the leaves.

scholarly journals Comprehensive Genome-Wide Association Analysis Reveals the Genetic Basis of Root System Architecture in Soybean

2020 ◽  
Vol 11 ◽  
Author(s):  
Waldiodio Seck ◽  
Davoud Torkamaneh ◽  
François Belzile
Keyword(s):  
Root System ◽  
System Architecture ◽  
Phenotypic Variation ◽  
Genetic Basis ◽  
Genome Wide Association Study ◽  
Primary Root ◽  
Root System Architecture ◽  
Genome Wide Association ◽  
Nucleotide Polymorphisms ◽  
Genome Wide

Increasing the understanding genetic basis of the variability in root system architecture (RSA) is essential to improve resource-use efficiency in agriculture systems and to develop climate-resilient crop cultivars. Roots being underground, their direct observation and detailed characterization are challenging. Here, were characterized twelve RSA-related traits in a panel of 137 early maturing soybean lines (Canadian soybean core collection) using rhizoboxes and two-dimensional imaging. Significant phenotypic variation (P < 0.001) was observed among these lines for different RSA-related traits. This panel was genotyped with 2.18 million genome-wide single-nucleotide polymorphisms (SNPs) using a combination of genotyping-by-sequencing and whole-genome sequencing. A total of 10 quantitative trait locus (QTL) regions were detected for root total length and primary root diameter through a comprehensive genome-wide association study. These QTL regions explained from 15 to 25% of the phenotypic variation and contained two putative candidate genes with homology to genes previously reported to play a role in RSA in other species. These genes can serve to accelerate future efforts aimed to dissect genetic architecture of RSA and breed more resilient varieties.

scholarly journals Biological nitrification inhibition in maize—isolation and identification of hydrophobic inhibitors from root exudates

2021 ◽  
Author(s):  
Junnosuke Otaka ◽  
Guntur Venkata Subbarao ◽  
Hiroshi Ono ◽  
Tadashi Yoshihashi
Keyword(s):  
Root Exudation ◽  
Root Systems ◽  
Root Surface ◽  
Maize Root ◽  
Nitrification Inhibition ◽  
Isolation And Identification ◽  
N Losses ◽  
Chemical Structures ◽  
Maize Roots ◽  
Biological Nitrification

AbstractTo control agronomic N losses and reduce environmental pollution, biological nitrification inhibition (BNI) is a promising strategy. BNI is an ecological phenomenon by which certain plants release bioactive compounds that can suppress nitrifying soil microbes. Herein, we report on two hydrophobic BNI compounds released from maize root exudation (1 and 2), together with two BNI compounds inside maize roots (3 and 4). On the basis of a bioassay-guided fractionation method using a recombinant nitrifying bacterium Nitrosomonas europaea, 2,7-dimethoxy-1,4-naphthoquinone (1, ED50 = 2 μM) was identified for the first time from dichloromethane (DCM) wash concentrate of maize root surface and named “zeanone.” The benzoxazinoid 2-hydroxy-4,7-dimethoxy-2H-1,4-benzoxazin-3(4H)-one (HDMBOA, 2, ED50 = 13 μM) was isolated from DCM extract of maize roots, and two analogs of compound 2, 2-hydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (HMBOA, 3, ED50 = 91 μM) and HDMBOA-β-glucoside (4, ED50 = 94 μM), were isolated from methanol extract of maize roots. Their chemical structures (1–4) were determined by extensive spectroscopic methods. The contributions of these four isolated BNI compounds (1–4) to the hydrophobic BNI activity in maize roots were 19%, 20%, 2%, and 4%, respectively. A possible biosynthetic pathway for zeanone (1) is proposed. These results provide insights into the strength of hydrophobic BNI activity released from maize root systems, the chemical identities of the isolated BNIs, and their relative contribution to the BNI activity from maize root systems.

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