Regulation of root system behavior by abiotic stress

Abstract

ABSTRACT:Soils abiotic stress is the biggest individual stress that limits the productivity of crops and distribution of plant speciesworldwide. Salt and drought soils affects the development of the radical system and thereby the entire plants organisms. Many aspects on how roots grow, develop and respond to changes in soil conditions are poorly understood. To achieve adaptation to soil environment of root growth, plants can adjust their root growth rate and direction determining the architecture of the radical system and the exploration of the medium. Almost all of this growth happens in the first millimeters of the root apex. What happens in this relatively small mass of cells can impact the performance of the crops under not optimal conditions like the hydric and salt stress. Many of the phenomena implicated in root cells response to external stimulus are regulated by membrane transport activity and their regulation factors. This review focuses in what we have learnt about the adaptation of plants to drought and salinity: how the roots senseand continues his growth in soils under abiotic stress. INTRODUCTIONIn plants the radicular system development is stimulated by cell divisions in meristem zone of all root apices. Some of behavior of roots are controlled by tropism responses in epidermal cell of different radical zones, allowing plant to reach water, nutrients and oxygen. Nevertheless, the formation and emergence of secondary roots is influenced also by the environment and determines the root system architecture in soil. Malamy (10) named the essential factors for the organogenesis and root growth as "intrinsic", and the ones that determine how plants respond to external signals to modulate the intrinsic factors as "response factors". How roots respond to these factors is one of the most intriguing cues for scientists today.