Seedling root system adaptation to water availability during maize domestication and global expansion.

The maize root system has been reshaped by indirect selection during global adaptation to new agricultural environments. In this study, we characterized the root systems of more than 9,000 global maize accessions and its wild relatives, defining the geographical signature and genomic basis of variation in seminal root number. We demonstrate that seminal root number has increased during maize domestication followed by a decrease in response to limited water availability in locally adapted varieties.

Deep-water uptake under drought improved due to locally increased root conductivity in maize, but not in faba bean.

Moderate soil drying can cause a strong decrease in the soil-root system conductance. The resulting impact on root water uptake depends on the spatial distribution of the altered conductance relatively to remaining soil water resources, which is largely unknown. Here, we analyzed the vertical distribution of conductance across root systems using a novel, noninvasive sensor technology on pot-grown faba bean and maize plants.

Stomatal conductance tracks soil-to-leaf hydraulic conductance in faba bean and maize during soil drying.

Although regulation of stomatal conductance is widely assumed to be the most important plant response to soil drying, the picture is incomplete when hydraulic conductance from soil to the leaf, upstream of the stomata, is not considered. Here, we investigated to what extent soil drying reduces the conductance between soil and leaf, whether this reduction differs between species, how it affects stomatal regulation, and where in the hydraulic pathway it occurs. To this end, we noninvasively and continuously measured the total root water uptake rate, soil water potential, leaf water potential, and stomatal conductance of 4-week-old, pot-grown maize (Zea mays) and faba bean (Vicia faba) plants during 4 days of water restriction.

The root system architecture of wheat establishing in soil is associated with varying elongation rates of seminal roots: quantification using 4D magnetic resonance imaging.

Seedling establishment is the first stage of crop productivity, and root phenotypes at seed emergence are critical to a successful start of shoot growth as well as for water and nutrient uptake. In this study, we investigate seedling establishment in winter wheat utilizing a newly developed workflow based on magnetic resonance imaging (MRI). Using the eight parents of the MAGIC (multi-parent advanced generation inter-cross) population we analysed the 4D root architecture of 288 individual seedlings grown in natural soils with plant neighbors over 3 d of development.

Proline-Mediated Drought Tolerance in the Barley ( L.) Isogenic Line Is Associated with Lateral Root Growth at the Early Seedling Stage.

A vigorous root system in barley promotes water uptake from the soil under water-limited conditions. We investigated three spring barley genotypes with varying water stress responses using rhizoboxes at the seedling stage. The genotypes comprised two elite German cultivars, and , and a near-isogenic line, The isogenic line harbors the wild allele .

A Wild Allele of Leads to Proline Accumulation in Spikes and Leaves of Barley Contributing to Improved Performance Under Reduced Water Availability.

Water stress (WS) during spike development strongly affects final grain yield and grain quality in cereals. Proline, an osmoprotectant amino-acid, may contribute to alleviating the effects of cell and tissue dehydration. We studied five spring barley genotypes contrasting in their drought response, including two introgression lines, and , harboring a allele originating from the wild barley accession .

Spatio-Temporal Variation in Water Uptake in Seminal and Nodal Root Systems of Barley Plants Grown in Soil.

The spatial and temporal dynamics of root water uptake in nodal and seminal roots are poorly understood, especially in relation to root system development and aging. Here we non-destructively quantify 1) root water uptake and 2) root length of nodal and seminal roots of barley in three dimensions during 43 days of growth. We developed a concentric split root system to hydraulically and physically isolate the seminal and nodal root systems.

Spatially Resolved Root Water Uptake Determination Using a Precise Soil Water Sensor.

To answer long-standing questions about how plants use and regulate water, an affordable, noninvasive way to determine local root water uptake (RWU) is required. Here, we present a sensor, the soil water profiler (SWaP), which can determine local soil water content (θ) with a precision of 6.10 cm ⋅ cm, an accuracy of 0.

Gibberellin Enhances the Anisotropy of Cell Expansion in the Growth Zone of the Maize Leaf.

Although plant organ shapes are defined by spatio-temporal variations of directional tissue expansion, this is a little characterized aspect of organ growth regulation. Although it is well known that the plant hormone gibberellin increases the leaf length/with ratio, its effects on cell expansion in the growing leaf are largely unknown. To understand how variations in rate and anisotropy of growth establish the typical monocotelydonous leaf shape, we studied the leaf growth zone of maize () with a kinematic analysis of cell expansion in the three directions of growth: proximo-distal, medio-lateral, and dorso-ventral.

Precise Volumetric Measurements of Any Shaped Objects with a Novel Acoustic Volumeter.

We introduce a novel technique to measure volumes of any shaped objects based on acoustic components. The focus is on small objects with rough surfaces, such as plant seeds. The method allows measurement of object volumes more than 1000 times smaller than the volume of the sensor chamber with both high precision and high accuracy.

Investigating the root plasticity response of Centaurea jacea to soil water availability changes from isotopic analysis.

Root water uptake is a key ecohydrological process for which a physically based understanding has been developed in the past decades. However, due to methodological constraints, knowledge gaps remain about the plastic response of whole plant root systems to a rapidly changing environment. We designed a laboratory system for nondestructive monitoring of stable isotopic composition in plant transpiration of a herbaceous species (Centaurea jacea) and of soil water across depths, taking advantage of newly developed in situ methods.

Localized bursting of mesocarp cells triggers catastrophic fruit cracking.

The so-called rain-cracking of sweet cherry fruit severely threatens commercial production. Simple observation tells us that cuticular microcracking (invisible) always precedes skin macrocracking (visible). The objective here was to investigate how a macrocrack develops.

Non-invasive imaging of plant roots in different soils using magnetic resonance imaging (MRI).

Background: Root systems are highly plastic and adapt according to their soil environment. Studying the particular influence of soils on root development necessitates the adaptation and evaluation of imaging methods for multiple substrates. Non-invasive 3D root images in soil can be obtained using magnetic resonance imaging (MRI).

Physical rupture of the xylem in developing sweet cherry fruit causes progressive decline in xylem sap inflow rate.

Xylem flow is progressively shut down during maturation beginning with minor veins at the stylar end and progressing to major veins and finally to bundles at the stem end. This study investigates the functionality of the xylem vascular system in developing sweet cherry fruit (Prunus avium L.).

Plant root tortuosity: an indicator of root path formation in soil with different composition and density.

Background and Aims Root soil penetration and path optimization are fundamental for root development in soil. We describe the influence of soil strength on root elongation rate and diameter, response to gravity, and root-structure tortuosity, estimated by average curvature of primary maize roots. Methods Soils with different densities (1·5, 1·6, 1·7 g cm-3), particle sizes (sandy loam; coarse sand mixed with sandy loam) and layering (monolayer, bilayer) were used.

Quantitative 3D Analysis of Plant Roots Growing in Soil Using Magnetic Resonance Imaging.

Precise measurements of root system architecture traits are an important requirement for plant phenotyping. Most of the current methods for analyzing root growth require either artificial growing conditions (e.g.

Magnetic resonance imaging of sugar beet taproots in soil reveals growth reduction and morphological changes during foliar Cercospora beticola infestation.

Cercospora leaf spot (CLS) infection can cause severe yield loss in sugar beet. Introduction of Cercospora-resistant varieties in breeding programmes is important for plant protection to reduce both fungicide applications and the risk of the development of fungal resistance. However, in vivo monitoring of the sugar-containing taproots at early stages of foliar symptoms and the characterization of the temporal development of disease progression has proven difficult.

Direct comparison of MRI and X-ray CT technologies for 3D imaging of root systems in soil: potential and challenges for root trait quantification.

Background: Roots are vital to plants for soil exploration and uptake of water and nutrients. Root performance is critical for growth and yield of plants, in particular when resources are limited. Since roots develop in strong interaction with the soil matrix, tools are required that can visualize and quantify root growth in opaque soil at best in 3D.

Belowground plant development measured with magnetic resonance imaging (MRI): exploiting the potential for non-invasive trait quantification using sugar beet as a proxy.

Both structural and functional properties of belowground plant organs are critical for the development and yield of plants but, compared to the shoot, much more difficult to observe due to soil opacity. Many processes concerning the belowground plant performance are not fully understood, in particular spatial and temporal dynamics and their interrelation with environmental factors. We used Magnetic Resonance Imaging (MRI) as a noninvasive method to evaluate which traits can be measured when a complex plant organ is monitored in-vivo while growing in the soil.

(11)C-PET imaging reveals transport dynamics and sectorial plasticity of oak phloem after girdling.

Carbon transport processes in plants can be followed non-invasively by repeated application of the short-lived positron-emitting radioisotope (11)C, a technique which has rarely been used with trees. Recently, positron emission tomography (PET) allowing 3D visualization has been adapted for use with plants. To investigate the effects of stem girdling on the flow of assimilates, leaves on first order branches of two-year-old oak (Quercus robur L.

Pot size matters: a meta-analysis of the effects of rooting volume on plant growth.

The majority of experiments in plant biology use plants grown in some kind of container or pot. We conducted a meta-analysis on 65 studies that analysed the effect of pot size on growth and underlying variables. On average, a doubling of the pot size increased biomass production by 43%.

MRI links stem water content to stem diameter variations in transpiring trees.

In trees, stem diameter variations are related to changes in stem water content, because internally stored water is depleted and replenished over a day. To confirm this relationship, non-invasive magnetic resonance imaging (MRI) was combined with point dendrometer measurements in three actively transpiring oak (Quercus robur L.) trees.

Non-invasive approaches for phenotyping of enhanced performance traits in bean.

Plant phenotyping is an emerging discipline in plant biology. Quantitative measurements of functional and structural traits help to better understand gene-environment interactions and support breeding for improved resource use efficiency of important crops such as bean (Phaseolus vulgaris L.).

A portable Halbach magnet that can be opened and closed without force: the NMR-CUFF.

Portable equipment for nuclear magnetic resonance (NMR) is becoming increasingly attractive for use in a variety of applications. One of the main scientific challenges in making NMR portable is the design of light-weight magnets that possess a strong and homogeneous field. Existing NMR magnets can provide such magnetic fields, but only for small samples or in small regions, or are rather heavy.