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High-resolution quantification of root dynamics in split-nutrient rhizoslides reveals rapid and strong proliferation of maize roots in response to local high nitrogen.

in 't Zandt D, Le Marié C, Kirchgessner N, Visser EJ, Hund A - J. Exp. Bot. (2015)

Bottom Line: This may be a desirable trait in breeding programmes, since it decreases NO3(-) leaching and N2O emission.By contrast, laterals on the side without N did not show any detectable elongation beyond the first day after their emergence.We conclude that split-nutrient rhizoslides have great potential to improve our knowledge about nitrogen responsiveness and selection for contrasting genotypes.

View Article: PubMed Central - PubMed

Affiliation: Department of Experimental Plant Ecology, Radboud University Nijmegen, Heijendaalseweg 135, 6525 AJ Nijmegen, The Netherlands Crop Science, Swiss Federal Institute of Technology Zurich, Universitätsstrasse 2, 8092 Zurich, Switzerland.

No MeSH data available.


Selection of the lateral initiation zone (LIZ): after a 5cm buffer zone, the last initiated lateral was defined as the beginning of the analysed branching zone. The length of the LIZ was 5cm.
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Figure 2: Selection of the lateral initiation zone (LIZ): after a 5cm buffer zone, the last initiated lateral was defined as the beginning of the analysed branching zone. The length of the LIZ was 5cm.

Mentions: In each run, four plants were grown in the split-nutrient rhizoslide setup. From two of these, the primary root was cut off 2 d after transplantation into the rhizoslides. This was replicated five times over time resulting in 20 plants; 10 with and 10 without primary root. From 4 d after transplantation until the end of the growing period, daily images were taken of the whole root system with a 21 mega pixel full-frame digital single-lens reflex camera (EOS 5D Mark II, Canon, Tokyo, Japan) equipped with a 50mm lens (compact macro 50mm f/2.5, Canon, Tokyo, Japan) and circular polarizer (Hama, Augsburg, Germany). For this, plants were placed in a frame with the camera fixed at 125cm distance from the root system. Imaging and image pre-processing was carried out as described by Le Marié et al. (2014). As soon as a root reached the side or bottom of the germination paper, it was not traced any further. Tracing was stopped to avoid modelling of effects that were due to the size of the rhizoslide rather than the effect of the nutrient solution or root age. Crown roots reaching the bottom appeared not to influence elongation rates of associated laterals or other parts of the root system (data not shown). Next, root elongation of the crown roots over time was calculated using R (R Core Team, 2013). Crown roots that were not present at one day after solution change (DASC) were discarded, as well as roots that had less than four measurement points, and roots showing zigzag patterns or negative root elongation rates. In a few cases, roots were growing on the wax layer. In these cases, root elongation values were removed during these periods. Crown lateral roots were traced with SmartRoot after solution change (time point 0). For this a 5cm zone on the crown root axis was chosen, the lateral initiation zone, beneath the last formed laterals and taking a 5cm buffer zone from the PVC plate into account (Fig. 2). This lateral initiation zone could be determined at 1−2 DASC, and from then on, the number of laterals was determined each day. Additionally, the five laterals that initiated first in this zone, were traced with SmartRoot until the end of the experimental period. Root elongation was calculated for these laterals using R.


High-resolution quantification of root dynamics in split-nutrient rhizoslides reveals rapid and strong proliferation of maize roots in response to local high nitrogen.

in 't Zandt D, Le Marié C, Kirchgessner N, Visser EJ, Hund A - J. Exp. Bot. (2015)

Selection of the lateral initiation zone (LIZ): after a 5cm buffer zone, the last initiated lateral was defined as the beginning of the analysed branching zone. The length of the LIZ was 5cm.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4585423&req=5

Figure 2: Selection of the lateral initiation zone (LIZ): after a 5cm buffer zone, the last initiated lateral was defined as the beginning of the analysed branching zone. The length of the LIZ was 5cm.
Mentions: In each run, four plants were grown in the split-nutrient rhizoslide setup. From two of these, the primary root was cut off 2 d after transplantation into the rhizoslides. This was replicated five times over time resulting in 20 plants; 10 with and 10 without primary root. From 4 d after transplantation until the end of the growing period, daily images were taken of the whole root system with a 21 mega pixel full-frame digital single-lens reflex camera (EOS 5D Mark II, Canon, Tokyo, Japan) equipped with a 50mm lens (compact macro 50mm f/2.5, Canon, Tokyo, Japan) and circular polarizer (Hama, Augsburg, Germany). For this, plants were placed in a frame with the camera fixed at 125cm distance from the root system. Imaging and image pre-processing was carried out as described by Le Marié et al. (2014). As soon as a root reached the side or bottom of the germination paper, it was not traced any further. Tracing was stopped to avoid modelling of effects that were due to the size of the rhizoslide rather than the effect of the nutrient solution or root age. Crown roots reaching the bottom appeared not to influence elongation rates of associated laterals or other parts of the root system (data not shown). Next, root elongation of the crown roots over time was calculated using R (R Core Team, 2013). Crown roots that were not present at one day after solution change (DASC) were discarded, as well as roots that had less than four measurement points, and roots showing zigzag patterns or negative root elongation rates. In a few cases, roots were growing on the wax layer. In these cases, root elongation values were removed during these periods. Crown lateral roots were traced with SmartRoot after solution change (time point 0). For this a 5cm zone on the crown root axis was chosen, the lateral initiation zone, beneath the last formed laterals and taking a 5cm buffer zone from the PVC plate into account (Fig. 2). This lateral initiation zone could be determined at 1−2 DASC, and from then on, the number of laterals was determined each day. Additionally, the five laterals that initiated first in this zone, were traced with SmartRoot until the end of the experimental period. Root elongation was calculated for these laterals using R.

Bottom Line: This may be a desirable trait in breeding programmes, since it decreases NO3(-) leaching and N2O emission.By contrast, laterals on the side without N did not show any detectable elongation beyond the first day after their emergence.We conclude that split-nutrient rhizoslides have great potential to improve our knowledge about nitrogen responsiveness and selection for contrasting genotypes.

View Article: PubMed Central - PubMed

Affiliation: Department of Experimental Plant Ecology, Radboud University Nijmegen, Heijendaalseweg 135, 6525 AJ Nijmegen, The Netherlands Crop Science, Swiss Federal Institute of Technology Zurich, Universitätsstrasse 2, 8092 Zurich, Switzerland.

No MeSH data available.