Some Mechanisms Modulating the Root Growth of Various Wheat Species under Osmotic-Stress Conditions

Abstract

The role of the root in water supply and plant viability is especially important if plants are subjected to stress at the juvenile stage. This article describes the study of morphophysiological and cytological responses, as well as elements of the anatomical structure of primary roots of three wheat species, Triticum monococcum L., Triticum dicoccum Shuebl., and Triticum aestivum L., to osmotic stress. It was shown that the degree of plasticity of root morphology in water deficit affected the growth and development of aboveground organs. It was found that in conditions of osmotic stress, the anatomical root modulations were species-specific. In control conditions the increase in absolute values of root diameter was reduced with the increase in the ploidy of wheat species. Species-specific cytological responses to water deficit of apical meristem cells were also shown. The development of plasmolysis, interpreted as a symptom of reduced viability apical meristem cells, was revealed. A significant increase in enzymatic activity of superoxide dismutase under osmotic stress was found to be one of the mechanisms that could facilitate root elongation in adverse conditions. The tetraploid species T. dicoccum Shuebl. were confirmed as a source of traits of drought tolerant primary root system for crosses with wheat cultivars.

Genetic Diversity in Natural Populations of Rhodiola Species of Different Adaptation Strategies

“…This test aims to evaluate the distribution of allele frequencies of the investigated genes across different taxonomic groups. In this context, we specifically investigated the interspecies polymorphism of the SOD genes [ 40 , 41 , 42 ]. A high (>0) D value implies a paucity of unusual alleles, indicating that the genetic polymorphism of the SOD genes is preserved without the development of any new forms.…”

“…The mechanism of action of proteins encoding superoxide dismutase genes comprises the successive reduction and oxidation of the metal of the active center of the enzyme by superoxide anion radicals, avoiding the conversion of the superoxide anion radical into a harmful hydroxyl radical and therefore having a favorable effect on plant growth and development and their response to abiotic stress [ 42 , 48 , 49 ]. At the same time, the regulatory regions, intron sequences, and coding portions of the SOD genes had the most variability.…”

Root System Architecture Plasticity of Bread Wheat in Response to Oxidative Burst under Extended Osmotic Stress

“…ROS play a dual role, causing damage and signaling to induce defense mechanisms [ 53 , 54 ]. When ROS reach damaging levels, plants trigger the antioxidants as a defense strategy [ 55 ], where the activity of antioxidant enzymes is observed in the primary roots of tolerant wheat seedling under osmotic stress [ 23 ].…”

“…ROS are potentially harmful since they are regarded as a key factor in cellular components, macromolecules, and DNA damage, resulting in irreparable metabolic dysfunction [ 21 , 22 ]. Enzymatic activity of superoxide dismutase (SOD) in wheat plants resulted in drought tolerant primary root elongation under osmotic stress [ 23 ]. It acts as signaling molecules for controlling plant programmed cell death (PCD) [ 24 ].…”

The Adaptation and Tolerance of Major Cereals and Legumes to Important Abiotic Stresses

“…Plants mostly rely on leaf relative water content, osmotic adjustments, and root architecture to enhance the yield under drought stress [ 175 ]. Reducing the size of the leaves can be regarded as a mechanism to minimize water loss by transpiration.…”