Evidence for root adaptation to a spatially discontinuous water availability in the absence of external water potential gradients

We hereby show that root systems adapt to a spatially discontinuous pattern of water availability even when the gradients of water potential across them are vanishingly small. A paper microfluidic approach allowed us to expose the entire root system ofBrassica rapaplants to a square array of water sources, separated by dry areas. Gradients in the concentration of water vapor across the root system were as small as 10−4⋅mM⋅m−1(∼4 orders of magnitude smaller than in conventional hydrotropism assays). Despite such minuscule gradients (which greatly limit the possible influence of the well-understood gradient-driven hydrotropic response), our results show that 1) individual roots as well as the root system as a whole adapt to the pattern of water availability to maximize access to water, and that 2) this adaptation increases as water sources become more rare. These results suggest that either plant roots are more sensitive to water gradients than humanmade water sensors by 3–5 orders of magnitude, or they might have developed, like other organisms, mechanisms for water foraging that allow them to find water in the absence of an external gradient in water potential.

Download Full-text

Rated-M for mesocosm: allowing the multimodal analysis of mature root systems in 3D

Emerging Topics in Life Sciences ◽

10.1042/etls20200278 ◽

2021 ◽

Author(s):

Tyler Dowd ◽

Samuel McInturf ◽

Mao Li ◽

Christopher N. Topp

Keyword(s):

Root System ◽

Water Availability ◽

Digital Camera ◽

Root Systems ◽

Root System Architecture ◽

Natural Setting ◽

Inexpensive Method ◽

3 Dimensional ◽

Multimodal Analysis ◽

Trade Offs

A plants’ water and nutrients are primarily absorbed through roots, which in a natural setting is highly dependent on the 3-dimensional configuration of the root system, collectively known as root system architecture (RSA). RSA is difficult to study due to a variety of factors, accordingly, an arsenal of methods have been developed to address the challenges of both growing root systems for imaging, and the imaging methods themselves, although there is no ‘best’ method as each has its own spectrum of trade-offs. Here, we describe several methods for plant growth or imaging. Then, we introduce the adaptation and integration of three complementary methods, root mesocosms, photogrammetry, and electrical resistance tomography (ERT). Mesocosms can allow for unconstrained root growth, excavation and preservation of 3-dimensional RSA, and modularity that facilitates the use of a variety of sensors. The recovered root system can be digitally reconstructed through photogrammetry, which is an inexpensive method requiring only an appropriate studio space and a digital camera. Lastly, we demonstrate how 3-dimensional water availability can be measured using ERT inside of root mesocosms.

Download Full-text

WATER POTENTIAL GRADIENTS AND RESISTANCES OF A SOIL-ROOT SYSTEM MEASURED WITH THE ROOT AND SOIL PSYCHROMETER

The Soil–Root Interface ◽

10.1016/b978-0-12-325550-1.50014-8 ◽

1979 ◽

pp. 99-113 ◽

Cited By ~ 2

Author(s):

H.B. SO

Keyword(s):

Water Potential ◽

Root System ◽

Potential Gradients

Download Full-text

Clifford Spinors and Root System Induction: $$H_4$$ and the Grand Antiprism

Advances in Applied Clifford Algebras ◽

10.1007/s00006-021-01139-2 ◽

2021 ◽

Vol 31 (3) ◽

Author(s):

Pierre-Philippe Dechant

Keyword(s):

Root System ◽

Root Systems ◽

Invariant Sets ◽

Simple Construction ◽

Reflection Groups ◽

Computational Work ◽

Algebraic Framework ◽

Underlying Geometry ◽

Coxeter Plane ◽

Insight Into

AbstractRecent work has shown that every 3D root system allows the construction of a corresponding 4D root system via an ‘induction theorem’. In this paper, we look at the icosahedral case of $$H_3\rightarrow H_4$$ H 3 → H 4 in detail and perform the calculations explicitly. Clifford algebra is used to perform group theoretic calculations based on the versor theorem and the Cartan–Dieudonné theorem, giving a simple construction of the $${\mathrm {Pin}}$$ Pin and $${\mathrm {Spin}}$$ Spin covers. Using this connection with $$H_3$$ H 3 via the induction theorem sheds light on geometric aspects of the $$H_4$$ H 4 root system (the 600-cell) as well as other related polytopes and their symmetries, such as the famous Grand Antiprism and the snub 24-cell. The uniform construction of root systems from 3D and the uniform procedure of splitting root systems with respect to subrootsystems into separate invariant sets allows further systematic insight into the underlying geometry. All calculations are performed in the even subalgebra of $${\mathrm {Cl}}(3)$$ Cl ( 3 ) , including the construction of the Coxeter plane, which is used for visualising the complementary pairs of invariant polytopes, and are shared as supplementary computational work sheets. This approach therefore constitutes a more systematic and general way of performing calculations concerning groups, in particular reflection groups and root systems, in a Clifford algebraic framework.

Download Full-text

On Closed Subsets of Root Systems

Canadian Mathematical Bulletin ◽

10.4153/cmb-1994-050-4 ◽

1994 ◽

Vol 37 (3) ◽

pp. 338-345 ◽

Cited By ~ 6

Author(s):

D. Ž. Doković ◽

P. Check ◽

J.-Y. Hée

Keyword(s):

Weyl Group ◽

Root System ◽

Irreducible Component ◽

Product Space ◽

Root Systems ◽

Inner Product Space ◽

Inner Product ◽

Closed Sets ◽

Finite Dimensional ◽

Real Inner Product Space

AbstractLet R be a root system (in the sense of Bourbaki) in a finite dimensional real inner product space V. A subset P ⊂ R is closed if α, β ∊ P and α + β ∊ R imply that α + β ∊ P. In this paper we shall classify, up to conjugacy by the Weyl group W of R, all closed sets P ⊂ R such that R\P is also closed. We also show that if θ:R —> R′ is a bijection between two root systems such that both θ and θ-1 preserve closed sets, and if R has at most one irreducible component of type A1, then θ is an isomorphism of root systems.

Download Full-text

Extension and Longitudinal Growth During the Development of Red Pine Root Systems

Canadian Journal of Forest Research ◽

10.1139/x75-016 ◽

1975 ◽

Vol 5 (1) ◽

pp. 109-121 ◽

Cited By ~ 29

Author(s):

D. C. F. Fayle

Keyword(s):

Root System ◽

Root Systems ◽

Red Pine ◽

Longitudinal Growth ◽

Rooting Depth ◽

Soil Conditions ◽

Moisture Availability ◽

Below Ground

Extension of the root system and stem during the first 30 years of growth of plantation-grown red pine (Pinusresinosa Ait.) on four sites was deduced by root and stem analyses. Maximum rooting depth was reached in the first decade and maximum horizontal extension of roots was virtually complete between years 15 and 20. The main horizontal roots of red pine seldom exceed 11 m in length. Elongation of vertical and horizontal roots was examined in relation to moisture availability and some physical soil conditions. The changing relations within the tree in lineal dimensions and annual elongation of the roots and stem are illustrated. The development of intertree competition above and below ground is considered.

Download Full-text

Accuracy and Usefulness of Psychrometer and Pressure Chamber for Evaluating Water Potentials of Pinus radiata Needles

Functional Plant Biology ◽

10.1071/pp9820499 ◽

1982 ◽

Vol 9 (5) ◽

pp. 499 ◽

Cited By ~ 5

Author(s):

BD Millar

Keyword(s):

Water Potential ◽

Pinus Radiata ◽

Xylem Sap ◽

Pressure Chamber ◽

Pressure Potential ◽

Pine Trees ◽

Average Water ◽

Potential Gradients ◽

Fundamental Uncertainty ◽

The One

Pressure chamber evaluations of xylem sap pressure potential (P) and thermocouple psychrometric evaluations of average water potential (Ψl) in needles from both transpiring and non-transpiring pine trees (Pinus radiata D. Don) were compared in order to determine the relative accuracy and usefulness of these methods for assessing Ψl. Markedly different but linear P v. Ψl relationships were obtained for pine needles of different age and also for the case where resin exudation masked the xylem and led to a 'resin error'. Evidence suggests that these differences are mainly due to injection and resin errors in pressure chamber determinations totalling as much as 1 MPa (a 10 bar). The psychrometric method appears to be the much more accurate. Radial water potential gradients across leaves did not result in differences between evaluations of P and Ψl, at least in P. radiata. The need for multiple 'calibrations' of the pressure chamber and the fundamental uncertainty about the constancy of such calibrations on the one hand and the slowness of the excised-needle psychrometer on the other can restrict the usefulness of these methods.

Download Full-text

Effects of Temperature on Root Morphology and Ectendomycorrhizal Development in Pinusresinosa Ait.

Canadian Journal of Forest Research ◽

10.1139/x75-024 ◽

1975 ◽

Vol 5 (2) ◽

pp. 171-175 ◽

Cited By ~ 5

Author(s):

Hugh E. Wilcox ◽

Ruth Ganmore-Neumann

Keyword(s):

Root Growth ◽

Root System ◽

Root Morphology ◽

Root Systems ◽

Second Order ◽

Root Temperature ◽

First Order ◽

Effects Of Temperature

Seedlings of Pinusresinosa were grown at root temperatures of 16, 21 and 27 °C, both aseptically and after inoculation with the ectendomycorrhizal fungus BDG-58. Growth after 3 months was significantly influenced by the presence of the fungus at all 3 temperatures. The influence of the fungus on root growth was obscured by the effects of root temperature on morphology. The root system at 16 and at 21 °C possessed many first-order laterals with numerous, well developed second-order branches, but those at 27 °C had only a few, relatively long, unbranched first-order laterals. Although the root systems of infected seedlings were larger, the fungus increased root growth in the same pattern as determined by the temperature.

Download Full-text

Unexpected relationships between δ13C and wine grape performance in organic farming

OENO One ◽

10.20870/oeno-one.2013.47.4.1556 ◽

2013 ◽

Vol 47 (4) ◽

pp. 269 ◽

Cited By ~ 5

Author(s):

Edoardo Antonio Costantino Costantini ◽

Alessandro Agnelli ◽

Pierluigi Bucelli ◽

Aldo Ciambotti ◽

Valentina Dell’Oro ◽

...

Keyword(s):

Water Stress ◽

Water Potential ◽

Soil Water ◽

Organic Farming ◽

Water Availability ◽

Stress Conditions ◽

Soil Water Availability ◽

Wine Grape ◽

Stem Water Potential ◽

Stem Water

Aim: To evaluate the relationship between carbon isotope ratio (δ13C) and wine grape viticultural and oenological performance in organic farming.Methods and results: The study was carried out for four years in the Chianti Classico wine production district (Central Italy), on five non irrigated vineyards conducted in organic farming. The reference variety was Sangiovese. Eleven sites were chosen for vine monitoring and grape sampling. The performance parameters were alcohol and must sugar content, sugar accumulation rate, mean berry weight, and extractable polyphenols. δ13C, stem water potential, and soil water availability were also monitored. Finally, soil nitrogen as well as yeast available nitrogen in the must were measured. δ13C was directly related to stem water potential and soil water deficit, and indicated a range of water stress conditions from none and moderate to strong. However, its relationship with viticultural and oenological results was contrary to expectation, that is, performance linearly increased along with soil moisture. On the other hand, the worst performance was obtained where both water and nitrogen were more limiting.Conclusions: The unexpected relationship between δ13C and Sangiovese performance was caused by low nitrogen availability. The studied sites all had low-fertility soils with poor or very poor nitrogen content. Therefore, in the plots where soil humidity was relatively higher, nitrogen plant uptake was favoured, and Sangiovese performance improved. Macronutrient being the main limiting factor, the performance was not lower in the plots where soil water availability was relatively larger. Therefore, the best viticultural result was obtained with no water stress conditions, at low rather than at intermediate δ13C values.Significance and impact of the study: Water nutrition is crucial for wine grape performance. δ13C is a method used to assess vine water status during the growing season and to estimate vine performance. A good performance is expected at moderate stress and intermediate δ13C values. A better knowledge of the interaction between water and nutrient scarcity is needed, as it can affect the use of δ13C to predict vine performance.

Download Full-text

Contemporary Concepts of Root System Architecture of Urban Trees

Arboriculture & Urban Forestry ◽

10.48044/jauf.2010.020 ◽

2010 ◽

Vol 36 (4) ◽

pp. 149-159

Author(s):

Susan Day ◽

P. Eric Wiseman ◽

Sarah Dickinson ◽

J. Roger Harris

Keyword(s):

Built Environment ◽

Root Growth ◽

Root System ◽

Root Architecture ◽

Root Systems ◽

Growth Patterns ◽

Urban Trees ◽

Rooting Depth ◽

Similar Species ◽

Urban Settings

Knowledge of the extent and distribution of tree root systems is essential for managing trees in the built environment. Despite recent advances in root detection tools, published research on tree root architecture in urban settings has been limited and only partially synthesized. Root growth patterns of urban trees may differ considerably from similar species in forested or agricultural environments. This paper reviews literature documenting tree root growth in urban settings as well as literature addressing root architecture in nonurban settings that may contribute to present understanding of tree roots in built environments. Although tree species may have the genetic potential for generating deep root systems (>2 m), rooting depth in urban situations is frequently restricted by impenetrable or inhospitable soil layers or by underground infrastructure. Lateral root extent is likewise subject to restriction by dense soils under hardscape or by absence of irrigation in dry areas. By combining results of numerous studies, the authors of this paper estimated the radius of an unrestricted root system initially increases at a rate of approximately 38 to 1, compared to trunk diameter; however, this ratio likely considerably declines as trees mature. Roots are often irregularly distributed around the tree and may be influenced by cardinal direction, terrain, tree lean, or obstacles in the built environment. Buttress roots, tap roots, and other root types are also discussed.

Download Full-text

Geospatial variation of grapevine water status, soil water availability, grape composition and sensory characteristics in a spatially heterogeneous premium wine grape vineyard

SOIL Discussions ◽

10.5194/soild-1-1013-2014 ◽

2014 ◽

Vol 1 (1) ◽

pp. 1013-1072

Author(s):

D. R. Smart ◽

S. Cosby Hess ◽

R. Plant ◽

O. Feihn ◽

H. Heymann ◽

...

Keyword(s):

Water Potential ◽

Soil Water ◽

Leaf Water Potential ◽

Water Availability ◽

Water Status ◽

Leaf Water ◽

Sensory Characteristics ◽

Soil Water Availability ◽

Wine Grape ◽

Available Water

Abstract. The geoscience component of terroir in wine grape production continues to be criticized for its quasi-mystical nature, and lack of testable hypotheses. Nonetheless, recent relational investigations are emerging and most involve water availability as captured by available water capacity (AWC, texture) or plant available water (PAW) in the root zone of soil as being a key factor. The second finding emerging may be that the degree of microscale variability in PAW and other soil factors at the vineyard scale renders larger regional characterizations questionable. Cimatic variables like temperature are well mixed, and its influence on wine characteristic is fairly well established. The influence of mesogeology on mesoclimate factors has also been characterized to some extent. To test the hypothesis that vine water status mirrors soil water availability, and controls fruit sensory and chemical properties at the vineyard scale we examined such variables in a iconic, selectively harvested premium winegrape vineyard in the Napa Valley of California during 2007 and 2008 growing seasons. Geo-referenced data vines remained as individual study units throughout data gathering and analysis. Cartographic exercises using geographic information systems (GIS) were used to vizualize geospatial variation in soil and vine properties. Highly significant correlations (P < 0.01) emerged for pre-dawn leaf water potential (ΨPD), mid-day leaf water potential (ΨL) and PAW, with berry size, berry weight, pruning weights (canopy size) and soluble solids content (°Brix). Areas yielding grapes with perceived higher quality had vines with (1) lower leaf water potential (LWP) both pre-dawn and mid-day, (2) smaller berry diameter and weight, (3) lower pruning weights, and (4) higher °Brix. A trained sensory panel found grapes from the more water-stressed vines had significantly sweeter and softer pulp, absence of vegetal character, and browner and crunchier seeds. Metabolomic analysis of the grape skins showed significant differences in accumulation of amino acids and organic acids. Data vines were categorized as non-stressed (ΨPD ≥ −7.9 bars and ΨL ≥ −14.9 bars) and stressed (ΨPD ≤ −8.0 bars and ΨL ≤ −15.0 bars) and subjected to analysis of variance. Significant separation emerged for vines categorized as non-stressed versus stressed at véraison, which correlated to the areas described as producing higher and lower quality fruit. This report does not advocate the use of stress levels herein reported. The vineyard was planted to a vigorous, deep rooted rootstock (V. rupestris cv. St. George), and from years of management is known to be able to withstand stress levels of the magnitude we observed. Nonetheless, the results may suggest there is not a linear relationship between physiological water stress and grape sensory characteristics, but rather the presence of an inflection point controlling grape composition as well as physiological development.

Download Full-text