The relationship between salt gland density and sodium accumulation/secretion in a wide selection from three Zoysia species

2016 ◽  
Vol 64 (4) ◽  
pp. 277 ◽  
Author(s):  
Akihiro Yamamoto ◽  
Masatsugu Hashiguchi ◽  
Ryo Akune ◽  
Takahito Masumoto ◽  
Melody Muguerza ◽  
...  

Several zoysiagrasses (Zoysia spp.) have been reported to have leaf-epidermal salt glands, and it has been suggested that salt gland density, salt secretion and salt tolerance are positively correlated. The economically most important Zoysia species are Zoysia japonica Steud., Zoysia matrella Merr., and Zoysia pacifica (Goudswaard) M. Hotta & Kuroki, and among these, Z. matrella is considered to be the most salt-tolerant. In this study, we investigated the salt gland density, and characterised the secretion and accumulation of Na+ of 48 accessions of the three Zoysia species. We did not find any morphological differences in salt glands of Z. japonica and Z. pacifica, but large bicellular salt glands were found only on the adaxial side of Z. matrella. In addition, salt gland density differed significantly within and between the species. Under salt stress, all accessions accumulated and secreted Na+ at different rates. Z. japonica was a salt-accumulating type, whereas Z. matrella and Z. pacifica secreted most of the absorbed salt. However, the correlation between salt gland density and salt accumulation/secretion were not observed. Furthermore, Z. pacifica had the lowest gland density but showed the highest Na+ uptake and a secretion rate similar to most salt-tolerant Z. matrella. These results suggest that response to salt stress, namely, salt accumulation/secretion, is different between species, and that salt gland density and salt secretion are not always positively correlated.

2008 ◽  
Vol 16 (2) ◽  
pp. 44-45
Author(s):  
Sheetal Rao ◽  
Michael W. Pendleton ◽  
Marla L. Binzel ◽  
E. Ann Ellis

Zoysia, a common turf grass, is characterized by the presence of functional salt glands. These glands are specialized structures through which the plants excrete excess salt. Research on the mechanism of salt secretion in Zoysia matrella (Manila grass) prompted the development of a specimen preparation technique that would preserve the secreted salt and salt gland. Conventional aqueous preparative techniques wash away the secreted salt on the leaf surface. A specimen preparation technique was modified from a simple cryo-preparative technique for examining hydrogels in the transmission electron microscope.


2019 ◽  
Vol 46 (1) ◽  
pp. 82 ◽  
Author(s):  
Fang Yuan ◽  
Xue Liang ◽  
Ying Li ◽  
Shanshan Yin ◽  
Baoshan Wang

Limonium bicolor is a typical recretohalophyte with salt glands in the epidermis, which shows maximal growth at moderate salt concentrations (100mM NaCl) but reduced growth in the presence of excess salt (more than 200mM). Jasmonic acid (JA) alleviates the reduced growth of L. bicolor under salt stress; however, the underlying mechanism is unknown. In this study we investigated the effects of exogenous methyl jasmonate (MeJA) application on L. bicolor growth at high NaCl concentrations. We found that treatment with 300mM NaCl led to dramatic inhibition of seedling growth that was significantly alleviated by the application of 0.03mM MeJA, resulting in a biomass close to that of plants not subjected to salt stress. To determine the parameters that correlate with MeJA-induced salt tolerance (assessed as the biomass production in saline and control conditions), we measured 14 physiological parameters relating to ion contents, plasma membrane permeability, photosynthetic parameters, salt gland density, and salt secretion. We identified a correlation between individual indicators and salt tolerance: the most positively correlated indicator was net photosynthetic rate, and the most negatively correlated one was relative electrical conductivity. These findings provide insights into a possible mechanism underlying MeJA-mediated salt stress alleviation.


1994 ◽  
Vol 267 (4) ◽  
pp. C990-C1001 ◽  
Author(s):  
S. A. Ernst ◽  
K. M. Crawford ◽  
M. A. Post ◽  
J. A. Cohn

Osmotic stress elicits hypertonic NaCl secretion and promotes structural and biochemical differentiation in avian salt glands. In addition to cholinergic control, Cl- secretion is stimulated by vasoactive intestinal peptide (VIP), suggesting that the cystic fibrosis transmembrane conductance regulator (CFTR) may be present and that its expression may be regulated by chronic salt stress. Anion efflux, assayed by 6-methoxy-N-(3-sulfopropyl)quinolinium fluorescence changes in single cells, was stimulated by VIP or 8-(4-chlorophenylthio)adenosine 3',5'-cyclic monophosphate. Immunoblots with a COOH-terminal peptide antibody to human CFTR revealed approximately 170- and approximately 180-kDa bands in lysates from control and salt-stressed glands, respectively. Both variants reduced to approximately 140 kDa after N-glycanase digestion and gave identical tryptic phosphopeptide maps after immunoprecipitation and phosphorylation by protein kinase A. CFTR was localized to apical membranes by immunofluorescence and, additionally, to subapical vesicles by immunoelectron microscopy. Salt stress induced an approximately twofold increase in CFTR abundance/cell protein (approximately 5-fold/cell) and intensified apical membrane immunofluorescence. For comparison, Na+ pump expression increased approximately fourfold per cell protein with little change in actin. Thus differentiation induced by salt stress is accompanied by alteration in CFTR abundance and glycosylation. Upregulation of CFTR likely contributes to increased efficiency of Cl- secretion.


2021 ◽  
Vol 22 (4) ◽  
pp. 2203 ◽  
Author(s):  
Chaoxia Lu ◽  
Fang Yuan ◽  
Jianrong Guo ◽  
Guoliang Han ◽  
Chengfeng Wang ◽  
...  

Soil salinization is a serious and growing problem around the world. Some plants, recognized as the recretohalophytes, can normally grow on saline–alkali soil without adverse effects by secreting excessive salt out of the body. The elucidation of the salt secretion process is of great significance for understanding the salt tolerance mechanism adopted by the recretohalophytes. Between the 1950s and the 1970s, three hypotheses, including the osmotic potential hypothesis, the transfer system similar to liquid flow in animals, and vesicle-mediated exocytosis, were proposed to explain the salt secretion process of plant salt glands. More recently, increasing evidence has indicated that vesicular transport plays vital roles in salt secretion of recretohalophytes. Here, we summarize recent findings, especially regarding the molecular evidence on the functional roles of vesicular trafficking in the salt secretion process of plant salt glands. A model of salt secretion in salt gland is also proposed.


Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 458 ◽  
Author(s):  
Rong Wang ◽  
Xi Wang ◽  
Kuan Liu ◽  
Xue-Jie Zhang ◽  
Luo-Yan Zhang ◽  
...  

As one of the most severe environmental stresses, salt stress can cause a series of changes in plants. In salt tolerant plant Zoysia macrostachya, germination, physiology, and genetic variation under salinity have been studied previously, and the morphology and distribution of salt glands have been clarified. However, no study has investigated the transcriptome of such species under salt stress. In the present study, we compared transcriptome of Z. macrostachya under normal conditions and salt stress (300 mmol/L NaCl, 24 h) aimed to identify transcriptome responses and molecular mechanisms under salt stress in Z. macrostachya. A total of 8703 differently expressed genes (DEGs) were identified, including 4903 up-regulated and 3800 down-regulated ones. Moreover, a series of molecular processes were identified by Gene Ontology (GO) analysis, and these processes were suggested to be closely related to salt tolerance in Z. macrostachya. The identified DEGs concentrated on regulating plant growth via plant hormone signal transduction, maintaining ion homeostasis via salt secretion and osmoregulatory substance accumulation and preventing oxidative damage via increasing the activity of ROS (reactive oxygen species) scavenging system. These changes may be the most important responses of Z. macrostachya under salt stress. Some key genes related to salt stress were identified meanwhile. Collectively, our findings provided valuable insights into the molecular mechanisms and genetic underpinnings of salt tolerance in Z. macrostachya.


2014 ◽  
Vol 522-524 ◽  
pp. 380-384
Author(s):  
Guo Liang Han ◽  
Ming Li Liu ◽  
Na Sui

The effects of NaCl on the growth, the number of salt gland and salt secretion ofAeluropus littoraliswere studied at different NaCl concentrations. Results showed that with the increase of NaCl concentration, the growth ofAeluropus littoraliswas inhibited and MDA content increased gradually. With the increase of NaCl concentration, fresh weight, dry weight of single plant decreased, andA. littoralissalt secretion increased significantly. Salt gland density was significantly higher with the increase of NaCl concentration, and the total number of salt glands on the low surface was more than that on the upper surface. At the same time, the average secretion rates of individual salt glands increased. These showed that the salt glands could effectively secrete salt outside the body to keep normal physiological function.


1997 ◽  
Vol 200 (13) ◽  
pp. 1895-1904 ◽  
Author(s):  
JP Hildebrandt

Chronic salt stress in ducklings (Anas platyrhynchos) resulted in a sustained accumulation of cyclic AMP in the secretory cells of the nasal salt glands. Adaptive increases in the activity of the Na+/K+-ATPase, measured as ATP hydrolysis rates in freshly isolated tissue, were observed after 12 h of salt stress. This change in enzyme activity was associated with increases in protein abundance in the - as well as in the ss-subunit of Na+/K+-ATPase and an increase in ss-subunit glycosylation. We investigated whether the increase in the cytosolic cyclic AMP concentration and the adaptive changes in Na+/K+-ATPase activity were causally related. Using an organotypic tissue culture system for salt gland slices from unstressed (naive) ducklings, we produced similar changes in Na+/K+-ATPase activity and subunit abundance by treating cultured tissue with drugs that elevate cytosolic cyclic AMP levels (forskolin, 8-CPT-cAMP) during a 15 h culture period. Protein synthesis assays using cultured tissue revealed that elevations in cytosolic cyclic AMP level mediate increases in Na+/K+-ATPase subunit abundance by slowing down the degradation of ATPase subunits. This increase in the amount of enzyme protein was associated with a significant increase in Na+/K+-ATPase activity in tissue homogenates. The time course of these changes in cyclic-AMP-treated cultured tissue resembled that observed in salt-stressed intact animals, indicating that the elevation in cyclic AMP level in salt gland tissue may constitute a portion of the signalling events ultimately leading to the adaptive increase in Na+/K+-ATPase activity in vivo.


HortScience ◽  
1997 ◽  
Vol 32 (2) ◽  
pp. 296-300 ◽  
Author(s):  
M.R. Foolad ◽  
G.Y. Lin

Seed of 42 wild accessions (Plant Introductions) of Lycopersicon pimpinellifolium Jusl., 11 cultigens (cultivated accessions) of L. esculentum Mill., and three control genotypes [LA716 (a salt-tolerant wild accession of L. pennellii Corr.), PI 174263 (a salt-tolerant cultigen), and UCT5 (a salt-sensitive breeding line)] were evaluated for germination in either 0 mm (control) or 100 mm synthetic sea salt (SSS, Na+/Ca2+ molar ratio equal to 5). Germination time increased in response to salt-stress in all genotypes, however, genotypic variation was observed. One accession of L. pimpinellifolium, LA1578, germinated as rapidly as LA716, and both germinated more rapidly than any other genotype under salt-stress. Ten accessions of L. pimpinellifolium germinated more rapidly than PI 174263 and 35 accessions germinated more rapidly than UCT5 under salt-stress. The results indicate a strong genetic potential for salt tolerance during germination within L. pimpinellifolium. Across genotypes, germination under salt-stress was positively correlated (r = 0.62, P < 0.01) with germination in the control treatment. The stability of germination response at diverse salt-stress levels was determined by evaluating germination of a subset of wild, cultivated accessions and the three control genotypes at 75, 150, and 200 mm SSS. Seeds that germinated rapidly at 75 mm also germinated rapidly at 150 mm salt. A strong correlation (r = 0.90, P < 0.01) existed between the speed of germination at these two salt-stress levels. At 200 mm salt, most accessions (76%) did not reach 50% germination by 38 days, demonstrating limited genetic potential within Lycopersicon for salt tolerance during germination at this high salinity.


Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1227
Author(s):  
Ali Mahmoud El-Badri ◽  
Maria Batool ◽  
Ibrahim A. A. Mohamed ◽  
Zongkai Wang ◽  
Ahmed Khatab ◽  
...  

Measuring metabolite patterns and antioxidant ability is vital to understanding the physiological and molecular responses of plants under salinity. A morphological analysis of five rapeseed cultivars showed that Yangyou 9 and Zhongshuang 11 were the most salt-tolerant and -sensitive, respectively. In Yangyou 9, the reactive oxygen species (ROS) level and malondialdehyde (MDA) content were minimized by the activation of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) for scavenging of over-accumulated ROS under salinity stress. Furthermore, Yangyou 9 showed a significantly higher positive correlation with photosynthetic pigments, osmolyte accumulation, and an adjusted Na+/K+ ratio to improve salt tolerance compared to Zhongshuang 11. Out of 332 compounds identified in the metabolic profile, 225 metabolites were filtrated according to p < 0.05, and 47 metabolites responded to salt stress within tolerant and sensitive cultivars during the studied time, whereas 16 and 9 metabolic compounds accumulated during 12 and 24 h, respectively, in Yangyou 9 after being sown in salt treatment, including fatty acids, amino acids, and flavonoids. These metabolites are relevant to metabolic pathways (amino acid, sucrose, flavonoid metabolism, and tricarboxylic acid cycle (TCA), which accumulated as a response to salinity stress. Thus, Yangyou 9, as a tolerant cultivar, showed improved antioxidant enzyme activity and higher metabolite accumulation, which enhances its tolerance against salinity. This work aids in elucidating the essential cellular metabolic changes in response to salt stress in rapeseed cultivars during seed germination. Meanwhile, the identified metabolites can act as biomarkers to characterize plant performance in breeding programs under salt stress. This comprehensive study of the metabolomics and antioxidant activities of Brassica napus L. during the early seedling stage is of great reference value for plant breeders to develop salt-tolerant rapeseed cultivars.


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