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| Titel |
Root type matters: measurements of water uptake by seminal, crown and lateral roots of maize |
| VerfasserIn |
Mutez Ali Ahmed, Mohsen Zarebanadkouki, Anders Kaestner, Andrea Carminati |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250129209
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| Publikation (Nr.) |
 EGU/EGU2016-9287.pdf |
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| Zusammenfassung |
| Roots play a key role in water acquisition and are a significant component of plant adaptation
to different environmental conditions. Although maize (Zea mays L.) is one of the most
important crops worldwide, there is limited information on the function of different root
segments and types in extracting water from soils. Aim of this study was to investigate the
location of root water uptake in mature maize.
We used neutron radiography to image the spatial distribution of maize roots and trace the
transport of injected deuterated water (D2O) in soil and roots. Maize plants were grown in
aluminum containers filled with a sandy soil that was kept homogeneously wet throughout
the experiment. When the plants were five weeks-old, we injected D2O into selected soil
regions. The transport of D2O was simulated using a diffusion-convection numerical model.
By fitting the observed D2O transport we quantified the diffusion coefficient and the water
uptake of the different root segments. The model was initially developed and tested
with two weeks-old maize (Ahmed et. al. 2015), for which we found that water
was mainly taken up by lateral roots and the water uptake of the seminal roots was
negligible.
Here, we used this method to measure root water uptake in a mature maize root system. The
root architecture of five weeks-old maize consisted of primary and seminal roots
with long laterals and crown (nodal) roots that emerged from the above ground
part of the plant two weeks after planting. The crown roots were thicker than the
seminal roots and had fewer and shorter laterals. Surprisingly, we found that the
water was mainly taken up by the crown roots and their laterals, while the lateral
roots of seminal roots, which were the main location of water uptake of younger
plants, stopped to take up water. Interestingly, we also found that in contrast to the
seminal roots, the crown roots were able to take up water also from their distal
segments.
We conclude that for the two weeks-old maize the function of lateral roots is to absorb water
from the soil, while the function of the primary and seminal roots is to axially transport water
to the shoot. For the five weeks-old maize, water was mainly taken up by the crown roots and
their associated laterals. The ability of crown roots to uptake water from the distal
segments can help maize to extract water from deep soil layers and better tolerate
drought.
Reference
Ahmed MA, Zarebanadkouki M, Kaestner A, Carminati A (2015) Measurements of water
uptake of maize roots: the key function of lateral roots. Plant and Soil 1–19. doi:
10.1007/s11104-015-2639-6 |
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