scholarly journals The Effect of AtHKT1;1 or AtSOS1 Mutation on the Expressions of Na+ or K+ Transporter Genes and Ion Homeostasis in Arabidopsis thaliana under Salt Stress

2019 ◽  
Vol 20 (5) ◽  
pp. 1085 ◽  
Author(s):  
Qian Wang ◽  
Chao Guan ◽  
Pei Wang ◽  
Qing Ma ◽  
Ai-Ke Bao ◽  
...  

HKT1 and SOS1 are two key Na+ transporters that modulate salt tolerance in plants. Although much is known about the respective functions of HKT1 and SOS1 under salt conditions, few studies have examined the effects of HKT1 and SOS1 mutations on the expression of other important Na+ and K+ transporter genes. This study investigated the physiological parameters and expression profiles of AtHKT1;1, AtSOS1, AtHAK5, AtAKT1, AtSKOR, AtNHX1, and AtAVP1 in wild-type (WT) and athkt1;1 and atsos1 mutants of Arabidopsis thaliana under 25 mM NaCl. We found that AtSOS1 mutation induced a significant decrease in transcripts of AtHKT1;1 (by 56–62% at 6–24 h), AtSKOR (by 36–78% at 6–24 h), and AtAKT1 (by 31–53% at 6–24 h) in the roots compared with WT. This led to an increase in Na+ accumulation in the roots, a decrease in K+ uptake and transportation, and finally resulted in suppression of plant growth. AtHKT1;1 loss induced a 39–76% (6–24 h) decrease and a 27–32% (6–24 h) increase in transcripts of AtSKOR and AtHAK5, respectively, in the roots compared with WT. At the same time, 25 mM NaCl decreased the net selective transport capacity for K+ over Na+ by 92% in the athkt1;1 roots compared with the WT roots. Consequently, Na+ was loaded into the xylem and delivered to the shoots, whereas K+ transport was restricted. The results indicate that AtHKT1;1 and AtSOS1 not only mediate Na+ transport but also control ion uptake and the spatial distribution of Na+ and K+ by cooperatively regulating the expression levels of relevant Na+ and K+ transporter genes, ultimately regulating plant growth under salt stress.

2018 ◽  
Vol 9 ◽  
Author(s):  
Inas Al-Younis ◽  
Aloysius Wong ◽  
Fouad Lemtiri-Chlieh ◽  
Sandra Schmöckel ◽  
Mark Tester ◽  
...  

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Yuzhu Huo ◽  
Wangdan Xiong ◽  
Kunlong Su ◽  
Yu Li ◽  
Yawen Yang ◽  
...  

The plant-specific transcription factor TCPs play multiple roles in plant growth, development, and stress responses. However, a genome-wide analysis of TCP proteins and their roles in salt stress has not been declared in switchgrass (Panicum virgatum L.). In this study, 42 PvTCP genes (PvTCPs) were identified from the switchgrass genome and 38 members can be anchored to its chromosomes unevenly. Nine PvTCPs were predicted to be microRNA319 (miR319) targets. Furthermore, PvTCPs can be divided into three clades according to the phylogeny and conserved domains. Members in the same clade have the similar gene structure and motif localization. Although all PvTCPs were expressed in tested tissues, their expression profiles were different under normal condition. The specific expression may indicate their different roles in plant growth and development. In addition, approximately 20 cis-acting elements were detected in the promoters of PvTCPs, and 40% were related to stress response. Moreover, the expression profiles of PvTCPs under salt stress were also analyzed and 29 PvTCPs were regulated after NaCl treatment. Taken together, the PvTCP gene family was analyzed at a genome-wide level and their possible functions in salt stress, which lay the basis for further functional analysis of PvTCPs in switchgrass.


2021 ◽  
Vol 22 (21) ◽  
pp. 11370
Author(s):  
Ewa Surówka ◽  
Dariusz Latowski ◽  
Michał Dziurka ◽  
Magdalena Rys ◽  
Anna Maksymowicz ◽  
...  

To determine the role of α- and γ-tocopherol (TC), this study compared the response to salt stress (200 mM NaCl) in wild type (WT) Arabidopsis thaliana (L.) Heynh. And its two mutants: (1) totally TC-deficient vte1; (2) vte4 accumulating γ-TC instead of α-TC; and (3) tmt transgenic line overaccumulating α-TC. Raman spectra revealed that salt-exposed α-TC accumulating plants were more flexible in regulating chlorophyll, carotenoid and polysaccharide levels than TC deficient mutants, while the plants overaccumulating γ-TC had the lowest levels of these biocompounds. Tocopherol composition and NaCl concentration affected xanthophyll cycle by changing the rate of violaxanthin de-epoxidation and zeaxanthin formation. NaCl treated plants with altered TC composition accumulated less oligosaccharides than WT plants. α-TC deficient plants increased their oligosaccharide levels and reduced maltose amount, while excessive accumulation of α-TC corresponded with enhanced amounts of maltose. Salt-stressed TC-deficient mutants and tmt transgenic line exhibited greater proline levels than WT plants, lower chlorogenic acid levels, and lower activity of catalase and peroxidases. α-TC accumulating plants produced more methylated proline- and glycine- betaines, and showed greater activity of superoxide dismutase than γ-TC deficient plants. Under salt stress, α-TC demonstrated a stronger regulatory effect on carbon- and nitrogen-related metabolites reorganization and modulation of antioxidant patterns than γ-TC. This suggested different links of α- and γ-TCs with various metabolic pathways via various functions and metabolic loops.


2019 ◽  
Author(s):  
Sareh Yousefirad ◽  
Hassan Soltanloo ◽  
Sayad Sanaz Ramezanpour ◽  
Khalil Zaynalinezhad ◽  
Vahid Shariati

Abstract Regarding the complexity of the mechanisms of salinity tolerance, the use of isogenic lines or mutants that have the same genetic background but show different tolerance to salinity is a suitable method to reduce the analytical complexity to study these mechanisms. In the current study, whole transcriptome analysis was evaluated using RNA-seq method between a salt-tolerant mutant line “73-M4-30” and its wild-type “Zarjou” cultivar at a seedling stage after six hours of exposure to salt stress (300 mM NaCl). Transcriptome sequencing yielded 20 million reads for each genotype. A total number of 7116 transcripts with differential expression were identified, 1586 and 1479 of which were obtained with significantly increased expression in the mutant and the wild-type, respectively. In addition, the families of WRKY, ERF, AP2/EREBP, NAC, CTR/DRE, AP2/ERF, MAD, MIKC, HSF, and bZIP were identified as the important transcription factors with specific expression in the mutant genotype. The RNA-seq results were confirmed in several time points using qRT-PCR of some important salt-responsive genes. In general, the results revealed that the mutant compared to its wild-type via fast stomach closure and consequently transpiration reduction under the salt stress, saved more sodium ion in the root and decreased its transfer to the shoot, and increased the amount of potassium ion leading to the maintenance a high ratio [K+]/­[Na+] in the shoot. Moreover, it caused a reduction in photosynthesis and respiration, resulting in the use of the stored energy and the carbon for maintaining the plant tissues, which is a mechanism of salt tolerance in plants. Up-regulation of catalase, peroxidase, and ascorbate peroxidase genes, which was probably due to the more accumulation of H2O2 in the wild-type compared to the mutant. Therefore, the wild-type initiated rapid ROS signals lead to less oxidative scavenging than the mutant. The mutant increased expression in the ion transporters and the channels related to the salinity to retain the ion homeostasis. Totally, the results demonstrated that the mutant responded better to the salt stress under both the osmotic and the ionic stress phases. Less damage was observed in the mutant compared to its wild-type under the salt stress.


Plants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 573 ◽  
Author(s):  
Xia Wan ◽  
Lu Peng ◽  
Jie Xiong ◽  
Xiaoyi Li ◽  
Jianmei Wang ◽  
...  

Because they are sessile organisms, plants need rapid and finely tuned signaling pathways to adapt to adverse environments, including salt stress. In this study, we identified a gene named Arabidopsis thaliana stress-induced BTB protein 1 (AtSIBP1), which encodes a nucleus protein with a BTB domain in its C-terminal side and is induced by salt and other stresses. The expression of the β-glucuronidase (GUS) gene driven by the AtSIBP1 promoter was found to be significantly induced in the presence of NaCl. The sibp1 mutant that lost AtSIBP1 function was found to be highly sensitive to salt stress and more vulnerable to salt stress than the wild type WT, while the overexpression of AtSIBP1 transgenic plants exhibited more tolerance to salt stress. According to the DAB staining, the sibp1 mutant accumulated more reactive oxygen species (ROS) than the WT and AtSIBP1 overexpression plants after salt stress. In addition, the expression levels of stress-induced marker genes in AtSIBP1 overexpression plants were markedly higher than those in the WT and sibp1 mutant plants. Therefore, our results demonstrate that AtSIBP1 was a positive regulator in salinity responses in Arabidopsis.


2020 ◽  
Vol 47 (10) ◽  
pp. 912
Author(s):  
Anis Ben Hsouna ◽  
Thaura Ghneim-Herrera ◽  
Walid Ben Romdhane ◽  
Amira Dabbous ◽  
Rania Ben Saad ◽  
...  

Soil salinity is an abiotic stress that reduces agricultural productivity. For decades, halophytes have been studied to elucidate the physiological and biochemical processes involved in alleviating cellular ionic imbalance and conferring salt tolerance. Recently, several interesting genes with proven influence on salt tolerance were isolated from the Mediterranean halophyte Lobularia maritima (L.) Desv. A better understanding of salt response in this species is needed to exploit its potential as a source of stress-related genes. We report the characterisation of L. maritima’s response to increasing NaCl concentrations (100–400 mM) at the physiological, biochemical and molecular levels. L. maritima growth was unaffected by salinity up to 100 mM NaCl and it was able to survive at 400 mM NaCl without exhibiting visual symptoms of damage. Lobularia maritima showed a Na+ and K+ accumulation pattern typical of a salt-includer halophyte, with higher contents of Na+ in the leaves and K+ in the roots of salt-treated plants. The expression profiles of NHX1, SOS1, HKT1, KT1 and VHA-E1 in salt-treated plants matched this Na+ and K+ accumulation pattern, suggesting an important role for these transporters in the regulation of ion homeostasis in leaves and roots of L. maritima. A concomitant stimulation in phenolic biosynthesis and antioxidant enzyme activity was observed under moderate salinity, suggesting a potential link between the production of polyphenolic antioxidants and protection against salt stress in L. maritima. Our findings indicate that the halophyte L. maritima can rapidly develop physiological and antioxidant mechanisms to adapt to salt and manage oxidative stress.


2019 ◽  
Vol 11 (2) ◽  
pp. 378 ◽  
Author(s):  
Jing Pan ◽  
Fei Peng ◽  
Xian Xue ◽  
Quangang You ◽  
Wenjuan Zhang ◽  
...  

Understanding the primary mechanisms for plant promotion under salt stress with plant growth promoting rhizobacteria (PGPR) inoculation of different salt-tolerant plant groups would be conducive to using PGPR efficiently. We conducted a meta-analysis to evaluate plant growth promotion and uncover its underlying mechanisms in salt-sensitive plants (SSP) and salt-tolerant plants (STP) with PGPR inoculation under salt stress. PGPR inoculation decreased proline, sodium ion (Na+) and malondialdehyde but increased plant biomass, nutrient acquisition (nitrogen, phosphorus, potassium ion (K+), calcium ion (Ca2+), and magnesium ion (Mg2+)), ion homeostasis (K+/Na+ ratio, Ca2+/Na+ ratio, and Mg2+/Na+ ratio), osmolytes accumulation (soluble sugar and soluble protein), antioxidants (superoxide dismutase), and photosynthesis (chlorophyll, carotenoid, and photosynthetic rate) in both SSP and STP. The effect size of total biomass positively correlated with the effect sizes of nutrient acquisition and the homeostasis of K+/Na+, and negatively correlated with the effect size of malondialdehyde in both SSP and STP. The effect size of total biomass also positively correlated with the effect sizes of carotenoid and the homeostasis in Ca2+/Na+ and Mg2+/Na+ and negatively correlated with the effect size of Na+ in SSP, but it only negatively correlated with the effect size of Ca2+ in STP. Our results suggest that the plant growth improvement depends on the nutrient acquisition enhancement in both SSP and STP, while ion homeostasis plays an important role and carotenoid may promote plant growth through protecting photosynthesis, reducing oxidative damage and promoting nutrient acquisition only in SSP after PGPR inoculation under salt stress.


Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 73
Author(s):  
Joseph L. Pegler ◽  
Jackson M.J. Oultram ◽  
Christopher P.L. Grof ◽  
Andrew L Eamens

In Arabidopsis thaliana (Arabidopsis), the microRNA399 (miR399)/PHOSPHATE2 (PHO2) expression module is central to the response of Arabidopsis to phosphate (PO4) stress. In addition, miR399 has been demonstrated to also alter in abundance in response to salt stress. We therefore used a molecular modification approach to alter miR399 abundance to investigate the requirement of altered miR399 abundance in Arabidopsis in response to salt stress. The generated transformant lines, MIM399 and MIR399 plants, with reduced and elevated miR399 abundance respectively, displayed differences in their phenotypic and physiological response to those of wild-type Arabidopsis (Col-0) plants following exposure to a 7-day period of salt stress. However, at the molecular level, elevated miR399 abundance, and therefore, altered PHO2 target gene expression in salt-stressed Col-0, MIM399 and MIR399 plants, resulted in significant changes to the expression level of the two PO4 transporter genes, PHOSPHATE TRANSPORTER1;4 (PHT1;4) and PHT1;9. Elevated PHT1;4 and PHT1;9 PO4 transporter levels in salt stressed Arabidopsis would enhance PO4 translocation from the root to the shoot tissue which would supply additional levels of this precious cellular resource that could be utilized by the aerial tissues of salt stressed Arabidopsis to either maintain essential biological processes or to mount an adaptive response to salt stress.


2018 ◽  
Vol 15 (2) ◽  
pp. 174-180 ◽  
Author(s):  
V. D. Olenieva ◽  
D. I. Lytvyn ◽  
A. I. Yemets ◽  
Ya. B. Blume

Aim. The aim of this work was to investigate changes in expression profiles of key genes involved in the development of autophagy by means of microtubules under the influence of sucrose starvation, osmotic and salt stresses. Methods. Arabidopsis thaliana seeds were sown aseptically on Murashige and Skoog solid medium. Salt and osmotic stresses were simulated by seed germination and seedlings cultivation on the media containing 150 mM NaCl and 10 mM mannitol, respectively. For investigation of starvation-induced autophagy plants were germinated and grown on sucrose-free medium. Results. Changes in expression of α-tubulin and atg8 genes had clearly defined stressdependent nature. Overexpression of tua1 and atg8e under starvation; tua3 and atg8f under osmotic stress; tua3 and atg8f, atg8e during salt stress indirectly testifies interaction between the structural units of autophagosomes and microtubules. It was shown that influence of investigated abiotic stimuli results in overexpression of elp3 and hda6 genes. Small increase in expression levels of hexokinase 2 and 3 was demonstrated. Conclusions. Transcriptome analysis of key genes involved in realization of autophagy induced by sucrose starvation, osmotic and salt stresses in Arabidopsis thaliana cells was conducted. Received data indirectly testifies interaction between the structural units of autophagosomes and microtubules and enables to point α-tubulin and atg8 genes, which are specific for the realization of autophagy induced by a certain abiotic stimuli. Expression profiles of elp3/deacetylases as well as hexokinases indicate the critical role of α-tubulin acetylation for autophagic response, that is involved in the development of programmed cell death.Keywords: autophagy, sucrose starvation, osmotic stress, salt stress, transcriptome analysis, α-tubulin, atg8.


Sign in / Sign up

Export Citation Format

Share Document