Root Development and Abiotic Stress Adaptation - Abiotic Stress: Plant Responses and Applications in Agriculture - page 153

plants due to a wide variety of processes, including nutrient and water uptake from soil, which
is a complex medium with high spatial and temporal environmental variability. Thus, it is not
surprising that RSA is highly influenced by environmental cues [9, 148]. The importance of
RSA in plant productivity stems from the fact that many soil resources are unevenly distributed
or are subject to localized depletion, so that the spatial deployment of the RS will largely
determine the ability of a plant to exploit those resources [4].The PERDP which regulates the
changes in RSA, can be considered as an evolutionary response to medium with high spatial
and temporal variability in resource supplies [148]. The genetic controls regarding root
deployment (PERDP) are still largely unknown. A great effort has been made to understand
the molecular components that regulate the formation, proliferation and maintenance of
meristems, either being embryo or pericycle-originated. Nevertheless, the facts behind their
regulation by environmental factors still leave many questions to be solved.
Plants are important to humans, as they provide food, fuel, fibres, medicines and materials.
As the global population is projected by the UN to rise to over 9 billion by 2050, the improve‐
ment of crops is becoming an increasingly pressuring issue. The new challenge arisen is to
solve the current and future obstacles to the maintenance of food supply security through
higher crop yields [10]. Water and nutrient availability limit the productivity in most agricul‐
tural ecosystems. In all environments characterized by low water and nutrient availability,
RSA is a fundamental aspect, the acquisition of soil resources by RS systems is therefore a
subject of considerable interest in agriculture [4]. RSA and PERDP are important agronomic
traits; the right architecture in a given environment allows plants to survive periods of water
of nutrient deficit, and compete effectively for resources [9]. Most of drought-resistant rice
varieties have a deeper and more highly branched RS than sensitive varieties [9].
Understanding the RSA and the PERDP holds potential for the exploitation and opening of
new options for genetic manipulation of the characteristics of the root, in order to both increase
food plant yield and optimize agricultural land use. Improved access to deep soil water,
inherently reducing the need for irrigation, is one potential benefit that could be achieved by
exploitation of RSA. Increase in root branching and root hair in crops may enable plants to
make more efficient use of existing soil nutrients and increase stress tolerance, improving
yields while decreasing the need for heavy fertilizer application [9, 10]. Understanding which
structures and environmental cues that regulate proliferation and elongation of the RS cells
will allow us to develop strategies to generate crops that possess greater soil exploration
capacities in order of a more efficient usage of nutrients and water present in the soil.
Acknowledgements
We thank Biol. V. Limones Briones for their assistance in the literature review. Writing of this
paper has been made possible by a financial support from Consejo Nacional de Ciencia y
Tecnología (CONACYT) proyecto Ciencia Básica clave CB2010/15685 and Red de Cuerpos
Académicos: Biotecnología para el desarrollo de una Agricultura sustentable, UAZ-CA 138.