Root surface

F For single-sided welded joints, concavity of the root surface shall not reduce the total thickness of the joint, including reinforcement, to less than the thickness of the thinner of the components being jointed. 

Jones, H.G. (1983). Estimation of an effective soil water potential at the root surface of transpiring plants. Plant, Cell and Environment, 6, 671-4. 

As already mentioned, molecular cross talk seems to be the prerequisite mechanism for most of root microbial infections. Indeed the initial step of any root colonization involves the movement of microbes to the plant root surface bacterial movement can be passive, via soil water flux, or active, via specific induction of flagellar activity by plant released compounds (chemotaxis) (Chaps. 4 and 7). Other important steps are adsorption and anchoring to the root surface. 

Various techniques for collection of root exudates are associated with the risk of root injury by rupture of root hairs and epidermal cells or rapid change of the environmental conditions (e.g., temperature, pH, oxygen availability) during transfer of root systems into trap solutions, application of absorbtion materials onto the root surface, and preparation of root systems for exudate collection. The possible impact of those stress treatments may be assessed by measuring parameters of plant growth in plants either. subjected or not subjected to the collection procedure (6) and by comparing exudation patterns after exposure of roots to the handling procedures with different intensity. 

Drought stress increases the soil mechanical impedance on plant roots, which in turn can stimulate root exudation (1,4,5). lncrea.sed release of mucilage may contribute to the maintainance of Zn uptake in dry soils by facilitating Zn transport to the root surface in mucilage-embedded soil particles (264). This effect might be supported by water transfer from the subsoil in the roots, which is... 

Since his early pioneering work on the rhizosphere (a term Hiltner used to describe specifically the interaction between bacteria and legume roots), our knowledge of the subject has greatly increased, and today perhaps a more appropriate definition of the rhizosphere is the field of action or influence of a root (1). The rhizosphere is generally considered to be a narrow zone of soil subject to the influence of living roots, where root exudates stimulate or inhibit microbial populations and their activities. The rhizoplane or root surface also provides a... 

A. J. Anderson, P. Habibzadegah-Tari, and C. S. Tepper, Molecular studies on the role of a root surface agglutinin in adherence and colonisation by Pseudomonas putida, Applied and Environmental Microbiology 54 315 (1987). 

N. C. Uren, Chemical reduction at the root surface. J. Plant Nutr. 5 5I5 (1982). 

These intraradical colonization patterns are clearly a consequence of events taking place at the root surface. In one of the many studies of this subject. Gollotte... 

In a cylindrical system, because equal amounts of water are being transported across successive concentric radial increments, the rate of flow of water must vary across the rhizosphere, with the fastest flows at the root surface. It is... 

The root surface at r is usually taken to be a fixed point. The effect of root thickening on uptake, where the root surface became a moving boundary has also been modeled (24). 

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