Morpho-Biological and Cytological Characterization of Tomato Roots (Solanum lycopersicum L., cv. Rekordsmen) Regenerated under NaCl Salinity in vitro

Баранова

Кононенко

et al. 2023

IJPB

Understanding the mechanisms of plant salt tolerance as a complex trait is an integral part of many studies, the results of which have been used in the breeding process. The aim of this study was to compare the root response of two tomato (Solanum lycopersicum L.) genotypes (breeding line YaLF and cultivar Recordsmen) differing in salt tolerance. Rhizogenesis was induced in tomato shoots in vitro with different concentrations of NaCl in the culture medium. A number of morphobiological and cytological parameters were evaluated at the organ, tissue, and cellular levels for possible use in a comprehensive assessment of genotypes for salt tolerance. The influence of NaCl caused disruption of the cell cycle and redistribution of cells in the phases of the cell cycle. An increase in the degree of vacuolization was shown in cv Recordsmen at 75 and 150 mM NaCl and in the YaLF line at 150 mM NaCl. Under salt action, an increase/decrease in the length of cells such as columella cells (both genotypes) and epidermal cells (in cv Recordsmen at 75 and 150 mM NaCl) was shown. Differences between genotypes were demonstrated by changes in the area of the central cylinder and primary root cortex cells, as well as by changes of the Snucleolus/Snucleus ratio in these cells. Transmission electron microscopy (TEM) showed the modification of the chromatin structure in the root cells of these genotypes. Various cytoskeletal disorders were revealed in interphase cells of the tomato root of cv Recordsmen and the YaLF line by immunofluorescent staining under saline conditions. These morphometric and cytological parameters can be used for a comparative evaluation of genotypes differing in salt tolerance in a comprehensive assessment of varieties.

Section: Discussionsupporting

confidence: 48%

Section: Immunofluorescent Staining With Antibodies To Tubulinmentioning

confidence: 99%

Characteristics of Root Cells during In Vitro Rhizogenesis under Action of NaCl in Two Tomato Genotypes Differing in Salt Tolerance

Баранова

Кононенко

et al. 2023

IJPB

“…It was shown that the osmotic pressure of the solution at a concentration of 100 mM mannitol in the culture medium did not affect the organization of the cortical microtubules in mutant plants [14], but led to microtubule depolymerization in control plants, thus providing increased resistance to salt damage. A change in the normal arrangement of interphase microtubules during salt stress was observed in the cells of maize [15,16], alfalfa [4], and tomato [17].…”

Section: Introductionmentioning

confidence: 97%

“…The modification of the cytoskeleton caused by salinity is accompanied by thinning of the network and thickening of microtubule bundles, which is shown for both osmotic and salt effects [3,17]. The bundle's fragmentation is characteristic under the toxic effect of ions, detected under high osmotic pressure only at strongly inhibitory growth concentrations [4].…”

Section: Introductionmentioning

confidence: 98%

Salt Stress-Induced Structural Changes Are Mitigated in Transgenic Tomato Plants Over-Expressing Superoxide Dismutase

Лазарева

Chaban

et al. 2020

Biology

Various abiotic stresses cause the appearance of reactive oxygen species (ROS) in plant cells, which seriously damage the cellular structures. The engineering of transgenic plants with higher production of ROS-scavenging enzyme in plant cells could protect the integrity of such a fine intracellular structure as the cytoskeleton and each cellular compartment. We analyzed the morphological changes in root tip cells caused by the application of iso-osmotic NaCl and Na2SO4 solutions to tomato plants harboring an introduced superoxide dismutase gene. To study the roots of tomato plants cultivar Belyi Naliv (WT) and FeSOD-transgenic line, we examined the distribution of ROS and enzyme-linked immunosorbent detection of α-tubulin. In addition, longitudinal sections of the root apexes were compared. Transmission electronic microscopy of atypical cytoskeleton structures was also performed. The differences in the microtubules cortical network between WT and transgenic plants without salt stress were detected. The differences were found in the cortical network of microtubules between WT and transgenic plants in the absence of salt stress. While an ordered microtubule network was revealed in the root cells of WT tomato, no such degree of ordering was detected in transgenic line cells. The signs of microtubule disorganization in root cells of WT plants were manifested under the NaCl treatment. On the contrary, the cytoskeleton structural organization in the transgenic line cells was more ordered. Similar changes, including the cortical microtubules disorganization, possibly associated with the formation of atypical tubulin polymers as a response to salt stress caused by Na2SO4 treatment, were also observed. Changes in cell size, due to both vacuolization and impaired cell expansion in columella zone and cap initials, were responsible for the root tip tissue modification.

“…The presented effective bioassay method was previously tested for evaluating some qualitative and quantitative cytological characterization of tomato roots (cv. Rekordsmen) de novo regenerated under 25-250 mM NaCl salinity [55], as well as for comparative anatomical and morphological studies of the epidermal and cortical parenchyma hypocotyl cells of tomato line YaLF and cv. Rekordsmen [56].…”

Section: Discussionmentioning

confidence: 99%

A Simple and Effective Bioassay Method Suitable to Comparative In Vitro Study of Tomato Salt Tolerance at Early Development Stages

Khaliluev

Ралдугина

et al. 2022

MPs

In vitro evaluation of tomato seeds and seedlings for salt tolerance has undoubted advantages (high productivity, as well as stability and reproducibility of the obtained experimental data due to the maintenance of constant controlled conditions) in comparison with open-field system and pot experiments. However, even high-quality seeds greatly differ in the uniformity of germination capacity and germination energy. Heterogeneous germination in the habit and developmental stage of plant material significantly distorts the obtaining of relevant experimental data suitable for correct interpretation. In our study, we propose a simple and effective bioassay method suitable to comparative in vitro study of tomato salt tolerance using shoot apex of seedlings at the early first-true-leaf stage. Shoot apexes cultured the on the root induction medium (RIM) supplemented with 0.2 mg/L indole-3-butyric acid (IBA) and NaCl at different concentrations (0–250 mM NaCl) revealed significant differences between two tomato genotypes (line YaLF and cv. Rekordsmen) at the organismal (measurements of CO2 gas exchange), organ (rhizogenesis frequency; number and length of de novo regenerated roots; root fresh (RFW) and dry (RDW) weights; shoot fresh (SFW) and dry (SDW) weights), tissue (the average cross-sectional area of epidermal and mesophylls cotyledonary cells) and cellular (ultrastructure of chloroplast and nuclear compartments) development levels. In addition, a quantitative comparison of proline and photosynthetic pigments contents under 75 and 150 mm NaCl treatments showed a different response between two tomato genotypes. The proposed methodological approach can be used for other plants with a high response to auxin-induced rhizogenesis in vitro, as well as for the comparative in vitro assessment of other abiotic stresses.