scholarly journals Asymmetry of Plant Cell Divisions under Salt Stress

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1811
Author(s):  
Ekaterina N. Baranova ◽  
Alexander A. Gulevich

Salt stress causes several damaging effects in plant cells. These commonly observed effects are the results of oxidative, osmotic, and toxic stresses. To ensure normal growth and development of tissues, the cellular compartments of multicellular plants have a unique system that provides the specified parameters of growth and differentiation. The cell shape and the direction of division support the steady development of the organism, the habit, and the typical shape of the organs and the whole plant. When dividing, daughter cells evenly or unevenly distribute the components of cytoplasm. Factors such as impaired osmotic regulation, exposure to toxic compounds, and imbalance in the antioxidant system cause disorders associated with the moving of organelles, distribution transformations of the endoplasmic reticulum, and the vacuolar compartment. In some cases, one can observe a different degree of plasmolysis manifestation, local changes in the density of cytoplasm. Together, these processes can cause disturbances in the direction of cell division, the formation of a phragmoplast, the formation of nuclei of daughter cells, and a violation of their fine structural organization. These processes are often accompanied by significant damage to the cytoskeleton, the formation of nonspecific structures formed by proteins of the cytoskeleton. The consequences of these processes can lead to the death of some cells or to a significant change in their morphology and properties, deformation of newly formed tissues and organs, and changes in the plant phenotype. Thus, as a result of significant violations of the cytoskeleton, causing critical destabilization of the symmetric distribution of the cell content, disturbances in the distribution of chromosomes, especially in polyploid cells, may occur, resulting in the appearance of micronuclei. Hence, the asymmetry of a certain component of the plant cell is a marker of susceptibility to abiotic damage.

1997 ◽  
Vol 137 (4) ◽  
pp. 891-898 ◽  
Author(s):  
Hiroyuki Adachi ◽  
Yasuhiro Takahashi ◽  
Takeshi Hasebe ◽  
Mikako Shirouzu ◽  
Shigeyuki Yokoyama ◽  
...  

The gapA gene encoding a novel RasGTPase-activating protein (RasGAP)–related protein was found to be disrupted in a cytokinesis mutant of Dictyostelium that grows as giant and multinucleate cells in a dish culture. The predicted sequence of the GAPA protein showed considerable homology to those of Gap1/Sar1 from fission yeast and the COOH-terminal half of mammalian IQGAPs, the similarity extending beyond the RasGAP-related domain. In suspension culture, gapA− cells showed normal growth in terms of the increase in cell mass, but cytokinesis inefficiently occurred to produce spherical giant cells. Time-lapse recording of the dynamics of cell division in a dish culture revealed that, in the case of gapA− cells, cytokinesis was very frequently reversed at the step in which the midbody connecting the daughter cells should be severed. Earlier steps of cytokinesis in the gapA− cells seemed to be normal, since myosin II was accumulated at the cleavage furrow. Upon starvation, gapA− cells developed and formed fruiting bodies with viable spores, like the wild-type cells. These results indicate that the GAPA protein is specifically involved in the completion of cytokinesis. Recently, it was reported that IQGAPs are putative effectors for Rac and CDC42, members of the Rho family of GTPases, and participate in reorganization of the actin cytoskeleton. Thus, it is possible that Dictyostelium GAPA participates in the severing of the midbody by regulating the actin cytoskeleton through an interaction with a member of small GTPases.


2021 ◽  
Vol 12 ◽  
Author(s):  
Pajaree Sonsungsan ◽  
Pheerawat Chantanakool ◽  
Apichat Suratanee ◽  
Teerapong Buaboocha ◽  
Luca Comai ◽  
...  

Salinity is an important environmental factor causing a negative effect on rice production. To prevent salinity effects on rice yields, genetic diversity concerning salt tolerance must be evaluated. In this study, we investigated the salinity responses of rice (Oryza sativa) to determine the critical genes. The transcriptomes of ‘Luang Pratahn’ rice, a local Thai rice variety with high salt tolerance, were used as a model for analyzing and identifying the key genes responsible for salt-stress tolerance. Based on 3' Tag-Seq data from the time course of salt-stress treatment, weighted gene co-expression network analysis was used to identify key genes in gene modules. We obtained 1,386 significantly differentially expressed genes in eight modules. Among them, six modules indicated a significant correlation within 6, 12, or 48h after salt stress. Functional and pathway enrichment analysis was performed on the co-expressed genes of interesting modules to reveal which genes were mainly enriched within important functions for salt-stress responses. To identify the key genes in salt-stress responses, we considered the two-state co-expression networks, normal growth conditions, and salt stress to investigate which genes were less important in a normal situation but gained more impact under stress. We identified key genes for the response to biotic and abiotic stimuli and tolerance to salt stress. Thus, these novel genes may play important roles in salinity tolerance and serve as potential biomarkers to improve salt tolerance cultivars.


2019 ◽  
Vol 20 (18) ◽  
pp. 4435 ◽  
Author(s):  
Ning Liu ◽  
Jie Chen ◽  
Tiehu Wang ◽  
Qing Li ◽  
Pengpeng Cui ◽  
...  

WAX INDUCER1/SHINE1 (WIN1) belongs to the AP2/EREBP transcription factor family and plays an important role in wax and cutin accumulation in plants. Here we show that BnWIN1 from Brassica napus (Bn) has dual functions in wax accumulation and oil synthesis. Overexpression (OE) of BnWIN1 led to enhanced wax accumulation and promoted growth without adverse effects on oil synthesis under salt stress conditions. Lipid profiling revealed that BnWIN1-OE plants accumulated more waxes with elevated C29-alkanes, C31-alkanes, C28-alcohol, and C29-alcohol relative to wild type (WT) under salt stress. Moreover, overexpression of BnWIN1 also increased seed oil content under normal growth conditions. BnWIN1 directly bound to the promoter region of genes encoding biotin carboxyl carrier protein 1 (BCCP1), glycerol-3-phosphate acyltransferase 9 (GPAT9), lysophosphatidic acid acyltransferase 5 (LPAT5), and diacylglycerol acyltransferase 2 (DGAT2) involved in the lipid anabolic process. Overexpression of BnWIN1 resulted in upregulated expression of numerous genes involved in de novo fatty acid synthesis, wax accumulation, and oil production. The results suggest that BnWIN1 is a transcriptional activator to regulate the biosynthesis of both extracellular and intracellular lipids.


2020 ◽  
Vol 71 (12) ◽  
pp. 3603-3612 ◽  
Author(s):  
Natanella Illouz-Eliaz ◽  
Idan Nissan ◽  
Ido Nir ◽  
Uria Ramon ◽  
Hagai Shohat ◽  
...  

Abstract Low gibberellin (GA) activity in tomato (Solanum lycopersicum) inhibits leaf expansion and reduces stomatal conductance. This leads to lower transpiration and improved water status under transient drought conditions. Tomato has three GIBBERELLIN-INSENSITIVE DWARF1 (GID1) GA receptors with overlapping activities and high redundancy. We tested whether mutation in a single GID1 reduces transpiration without affecting growth and productivity. CRISPR-Cas9 gid1 mutants were able to maintain higher leaf water content under water-deficit conditions. Moreover, while gid1a exhibited normal growth, it showed reduced whole-plant transpiration and better recovery from dehydration. Mutation in GID1a inhibited xylem vessel proliferation, which led to lower hydraulic conductance. In stronger GA mutants, we also found reduced xylem vessel expansion. These results suggest that low GA activity affects transpiration by multiple mechanisms: it reduces leaf area, promotes stomatal closure, and reduces xylem proliferation and expansion, and as a result, xylem hydraulic conductance. We further examined if gid1a performs better than the control M82 in the field. Under these conditions, the high redundancy of GID1s was lost and gid1a plants were semi-dwarf, but their productivity was not affected. Although gid1a did not perform better under drought conditions in the field, it exhibited a higher harvest index.


1986 ◽  
Vol 13 (5) ◽  
pp. 659 ◽  
Author(s):  
SP Robinson ◽  
GP Jones

Glycinebetaine was determined in leaves and in isolated chloroplasts of spinach (Spinacia oleracea) by nuclear magnetic resonance spectroscopy. Some leakage of glycinebetaine from the chloroplasts occurred during the isolation so the concentration in chloroplasts in vivo could be up to 1.5 times higher than that measured in isolated chloroplasts. It was demonstrated that any contamination of the chloroplast preparations by glycinebetaine originating from other cellular compartments or from broken chloroplasts would have amounted to less than 10% of the measured values. Leaf osmotic potential of salt-stressed plants was -2.09 MPa compared to -0.91 MPa in non-stressed controls. This was accompanied by a sixfold increase in glycinebetaine content in the leaf but the levels of choline and proline were not increased. In chloroplasts isolated from control leaves the calculated glycinebetaine concentration was 26 mM which was 10-fold higher than the concentration in the leaf as a whole but only contributed 7% of the osmotic potential of the chloroplast. Chloroplasts from salt-stressed plants contained up to 300 mM glycinebetaine which was 20 times the concentration in the leaf as a whole. The glycinebetaine concentration in chloroplasts from salt-stressed leaves was equivalent to an osmotic potential of -0.75 MPa and this contributed 36% of the osmotic potential of the chloroplast and 64% of the decrease in osmotic potential induced by salt stress. At least 30-40% of the total leaf glycinebetaine was localized in the chloroplast. The results demonstrate that glycinebetaine accumulates in chloroplasts to provide osmotic adjustment during salt stress and provide support for the hypothesis that glycinebetaine is a compatible cytoplasmic solute which may be preferentially located in the cytoplasm of cells.


2010 ◽  
Vol 21 (10) ◽  
pp. 1772-1782 ◽  
Author(s):  
Xia Li ◽  
Yunrui Du ◽  
Steven Siegel ◽  
Susan Ferro-Novick ◽  
Peter Novick

Inheritance of the endoplasmic reticulum (ER) requires Ptc1p, a type 2C protein phosphatase of Saccharomyces cerevisiae . Genetic analysis indicates that Ptc1p is needed to inactivate the cell wall integrity (CWI) MAP kinase, Slt2p. Here we show that under normal growth conditions, Ptc1p inactivates Slt2p just as ER tubules begin to spread from the bud tip along the cortex. In ptc1Δ cells, the propagation of cortical ER from the bud tip to the periphery of the bud is delayed by hyperactivation of Slt2p. The pool of Slt2p that controls ER inheritance requires the CWI pathway scaffold, Spa2p, for its retention at the bud tip, and a mutation within Slt2p that prevents its association with the bud tip blocks its role in ER inheritance. These results imply that Slt2p inhibits a late step in ER inheritance by phosphorylating a target at the tip of daughter cells. The PI4P5-kinase, Mss4p, is an upstream activator of this pool of Slt2p. Ptc1p-dependant inactivation of Slt2p is also needed for mitochondrial inheritance; however, in this case, the relevant pool of Slt2p is not at the bud tip.


2017 ◽  
Vol 409 (17) ◽  
pp. 4233-4245 ◽  
Author(s):  
Luca Zoia ◽  
Diego Tamburini ◽  
Marco Orlandi ◽  
Jeannette Jacqueline Łucejko ◽  
Anika Salanti ◽  
...  

PROTEOMICS ◽  
2009 ◽  
Vol 9 (5) ◽  
pp. 1416-1416
Author(s):  
Noor Remmerie ◽  
Luc Roef ◽  
Eveline Van De Slijke ◽  
Jelle Van Leene ◽  
Geert Persiau ◽  
...  

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2544
Author(s):  
Sami Hannachi ◽  
Stefaan Werbrouck ◽  
Insaf Bahrini ◽  
Abdelmuhsin Abdelgadir ◽  
Hira Affan Siddiqui

Previously, an efficient regeneration protocol was established and applied to regenerate plants from calli lines that could grow on eggplant leaf explants after a stepwise in vitro selection for tolerance to salt stress. Plants were regenerated from calli lines that could tolerate up to 120 mM NaCl. For further in vitro and in vivo evaluation, four plants with a higher number of leaves and longer roots were selected from the 32 plants tested in vitro. The aim of this study was to confirm the stability of salt tolerance in the progeny of these four mutants (‘R18’, ‘R19’, ‘R23’ and ‘R30’). After three years of in vivo culture, we evaluated the impact of NaCl stress on agronomic, physiological and biochemical parameters compared to the parental control (‘P’). The regenerated and control plants were assessed under in vitro and in vivo conditions and were subjected to 0, 40, 80 and 160 mM of NaCl. Our results show significant variation in salinity tolerance among regenerated and control plants, indicating the superiority of four regenerants (‘R18’, ‘R19’, ‘R23’ and ‘R30’) when compared to the parental line (‘P’). In vitro germination kinetics and young seedling growth divided the lines into a sensitive and a tolerant group. ‘P’ tolerate only moderate salt stress, up to 40 mM NaCl, while the tolerance level of ‘R18’, ‘R19’, ‘R23’ and ‘R30’ was up to 80 mM NaCl. The quantum yield of PSII (ΦPSII) declined significantly in ‘P’ under salt stress. The photochemical quenching was reduced while nonphotochemical quenching rose in ‘P’ under salt stress. Interestingly, the regenerants (‘R18’, ‘R19’, ‘R23’ and ‘R30’) exhibited high apparent salt tolerance by maintaining quite stable Chl fluorescence parameters. Rising NaCl concentration led to a substantial increase in foliar proline, malondialdehyde and soluble carbohydrates accumulation in ‘P’. On the contrary, ‘R18’, ‘R19’, ‘R23’ and ‘R30’ exhibited a decline in soluble carbohydrates and a significant enhancement in starch under salinity conditions. The water status reflected by midday leaf water potential (ψl) and leaf osmotic potential (ψπ) was significantly affected in ‘P’ and was maintained a stable level in ‘R18’, ‘R19’, ‘R23’ and ‘R30’ under salt stress. The increase in foliar Na+ and Cl− content was more accentuated in parental plants than in regenerated plants. The leaf K+, Ca2+ and Mg2+ content reduction was more aggravated under salt stress in ‘P’. Under increased salt concentration, ‘R18’, ‘R19’, ‘R23’ and ‘R30’ associate lower foliar Na+ content with a higher plant tolerance index (PTI), thus maintaining a normal growth, while foliar Na+ accumulation was more pronounced in ‘P’, revealing their failure in maintaining normal growth under salinity stress. ‘R18’, ‘R19’, ‘R23’ and ‘R30’ showed an obvious salt tolerance by maintaining significantly high chlorophyll content. In ‘R18’, ‘R19’, ‘R23’ and ‘R30’, the enzyme scavenging machinery was more performant in the roots compared to the leaves. Salt stress led to a significant augmentation of catalase, ascorbate peroxidase and guaiacol peroxidase activities in the roots of ‘R18’, ‘R19’, ‘R23’ and ‘R30’. In contrast, enzyme activities were less enhanced in ‘P’, indicating lower efficiency to cope with oxidative stress than in ‘R18’, ‘R19’, ‘R23’ and ‘R30’. ACC deaminase activity was significantly higher in ‘R18’, ‘R19’, ‘R23’ and ‘R30’ than in ‘P’. The present study suggests that regenerated plants ‘R18’, ‘R19’, ‘R23’ and ‘R30’ showed an evident stability in tolerating salinity, which shows their potential to be adopted as interesting selected mutants, providing the desired salt tolerance trait in eggplant.


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