ABSTRACT
The survival of plants (including medicinal plants) is considerably dependent on their ability to adapt to the environmental conditions under which they live. Because of their immobility, plants need to recognize and respond to external stimuli sensitively and properly to ensure their survival. Abiotic stress responses in plants occur at various organ levels among which the root-specific processes are of particular importance. Under normal growth conditions, the root absorbs water and nutrients from the soil and supplies them throughout the plant body, thereby playing a pivotal role in maintaining cellular homeostasis. However, this balanced system is altered during the stress period when roots are forced to adopt several structural and functional modifications. Examples of these modifications include phenotypic, cellular, and molecular changes such as alteration of metabolism and membrane characteristics, hardening of the cell wall, and reduction of root length. These changes are often caused by a single or combined effect of several abiotic stress responsive pathways that can be best explored at the global level using high-throughput approaches such as proteomics (Ghosh and Xu 2014). Plant neurobiology, as a recently focused field of plant biology research, aims to understand how plants process the information they obtain from their environment to optimally develop, prosper, and reproduce. The behavior plants exhibit is coordinated across the whole organism by some form of integrated signaling, communication, and response system. This system includes long-distance electrical signals, vesicle-mediated transport of auxin in specialized vascular tissue, and the production of chemicals known to be neuronal in animals (Brenner et al. 2006; Baluška and Mancuso 2009). Plant neurobiology emphasizes the transit section of root apices (Baluška et al. 2010) considered as the “brain-like” organ of the plant where the synchronization of electrical activity was found (Baluška et al. 2009). It should be emphasized that these findings are extraordinarily important for plants that are under stress conditions.
