Reduced expression of a vesicle trafficking-related ATPase SKD1 decreases salt tolerance in Arabidopsis

2010 ◽  
Vol 37 (10) ◽  
pp. 962 ◽  
Author(s):  
Li-Wei Ho ◽  
Ting-Ting Yang ◽  
Shyan-Shu Shieh ◽  
Gerald E. Edwards ◽  
Hungchen E. Yen

In this study we present the functional characterisation of SKD1 (suppressor of K+ transport growth defect) in salt tolerance of higher plants. SKD1 participates in endosome-mediated protein sorting and expression of SKD1 is salt-induced in Na+ storage cells of halophyte ice plant. Transgenic Arabidopsis with reduced SKD1 expression were generated by expressing AtSKD1 in antisense orientation. Relative root growth rate of antisense seedlings was slower than that of wild-type seedlings under salt treatment. The Na+/K+ ratio doubled in the antisense seedlings compared with the wild-type seedlings indicating a loss in Na+/K+ homeostasis. The PSII activity dropped following one week of salt-stress in antisense plants whereas wild-type plants maintained normal activity. Upon germination, transgenic seedlings developed multiple roots where each root had lower density of lateral roots. Application of 1-naphthaleneacetic acid restored the ability of transgenic seedlings to form lateral roots. Expression profiling analyses revealed that expressions of one stress-related kinase, several salt-induced transcription factors and one auxin efflux transporter were altered in antisense seedlings. With decreased expression of SKD1, plants experience a reduced salinity response and altered root development indicating the importance of intracellular vesicular trafficking in both auxin-mediated plant growth and in maintaining ion homeostasis under salt stress.

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.


2008 ◽  
Vol 35 (3) ◽  
pp. 185 ◽  
Author(s):  
Le-Yi Shi ◽  
Hong-Qing Li ◽  
Xiao-Ping Pan ◽  
Guo-Jiang Wu ◽  
Mei-Ru Li

In this paper, transgenic torenia plants expressing the AtNHX5 gene from Arabidopsis in sense and antisense orientations were produced to examine the potential role of AtNHX5 in plant salt tolerance and development. We found that torenia plants overexpressing AtNHX5 showed markedly enhanced tolerance to salt stress compared with both wild-type and antisense AtNHX5 transgenic plants upon salt stress. Measurements of ion levels indicated that Na+ and K+ contents were all higher in AtNHX5 overexpressing shoots than in those of both wild-type and antisense AtNHX5 shoots treated with 50 mm NaCl. This indicated that overexpression of AtNHX5 could improve the salt tolerance of transgenic torenia via accumulation of both Na+ and K+ in shoots, in which overall ion homeostasis and osmotic adjustment was changed to sustain the increase in shoot salt tolerance. Further, we found that overexpression of AtNHX5 in torenia significantly improved the shoot regeneration frequency in leaf explants and increased the plantlet survival rate when transferring the regenerated plants to soil. In addition, the AtNHX5 expressing plants produced flowers earlier than both wild-type and the antisense AtNHX5 plants. Taken together, the results indicated that AtNHX5 functions not only in plant salt tolerance but also in plant growth and development.


2018 ◽  
Vol 19 (10) ◽  
pp. 3108 ◽  
Author(s):  
Hongxia Miao ◽  
Peiguang Sun ◽  
Juhua Liu ◽  
Jingyi Wang ◽  
Biyu Xu ◽  
...  

Rho-like GTPases from plants (ROPs) are plant-specific molecular switches that are crucial for plant survival when subjected to abiotic stress. We identified and characterized 17 novel ROP proteins from Musa acuminata (MaROPs) using genomic techniques. The identified MaROPs fell into three of the four previously described ROP groups (Groups II–IV), with MaROPs in each group having similar genetic structures and conserved motifs. Our transcriptomic analysis showed that the two banana genotypes tested, Fen Jiao and BaXi Jiao, had similar responses to abiotic stress: Six genes (MaROP-3b, -5a, -5c, -5f, -5g, and -6) were highly expressed in response to cold, salt, and drought stress conditions in both genotypes. Of these, MaROP5g was most highly expressed in response to salt stress. Co-localization experiments showed that the MaROP5g protein was localized at the plasma membrane. When subjected to salt stress, transgenic Arabidopsis thaliana overexpressing MaROP5g had longer primary roots and increased survival rates compared to wild-type A. thaliana. The increased salt tolerance conferred by MaROP5g might be related to reduced membrane injury and the increased cytosolic K+/Na+ ratio and Ca2+ concentration in the transgenic plants as compared to wild-type. The increased expression of salt overly sensitive (SOS)-pathway genes and calcium-signaling pathway genes in MaROP5g-overexpressing A. thaliana reflected the enhanced tolerance to salt stress by the transgenic lines in comparison to wild-type. Collectively, our results suggested that abiotic stress tolerance in banana plants might be regulated by multiple MaROPs, and that MaROP5g might enhance salt tolerance by increasing root length, improving membrane injury and ion distribution.


2017 ◽  
Vol 39 (3) ◽  
Author(s):  
Davood Kiani ◽  
Hassan Soltanloo ◽  
Seyyede Sanaz Ramezanpour ◽  
Ali Asghar Nasrolahnezhad Qumi ◽  
Ahad Yamchi ◽  
...  

2020 ◽  
Author(s):  
Pan Zhang ◽  
Tianqi Duo ◽  
Fengdan Wang ◽  
Xunzhong Zhang ◽  
Zouzhuan Yang ◽  
...  

Abstract Background: Soil salinization is a major limiting factor for crop cultivation. Switchgrass is a perennial rhizomatous bunchgrass that is considered an ideal plant for marginal lands, including sites with saline soil. Here, we investigated the physiological responses and transcriptome changes in the roots of two switchgrass genotypes under alkaline salt stress.Results: Alkaline salt stress significantly affected the membrane, osmotic adjustment and antioxidant systems in switchgrass roots, and the ASTTI values between Alamo and AM-314/MS-155 were divergent at different time points. A total of 108,319 unigenes were obtained after reassembly, including 73,636 unigenes in AM-314/MS-155 and 65,492 unigenes in Alamo. A total of 10,219 DEGs were identified, and the number of upregulated genes in Alamo was much greater than that in AM-314/MS-155 in both the early and late stages of alkaline salt stress. The DEGs in AM-314/MS-155 were mainly concentrated in the early stage, while Alamo showed greater advantages in the late stage. These DEGs were mainly enriched in plant-pathogen interactions, ubiquitin-mediated proteolysis and glycolysis/gluconeogenesis pathways. We characterized 1,480 TF genes into 64 TF families, and the most abundant TF family was the C2H2 family, followed by the bZIP and bHLH families. A total of 1,718 PKs were predicted, including CaMK, CDPK, MAPK and RLK. WGCNA revealed that the DEGs in the blue, brown, dark magenta and light steel blue 1 modules were associated with the physiological changes in roots of switchgrass under alkaline salt stress. The consistency between the qRT-PCR and RNA-Seq results confirmed the reliability of the RNA-seq sequencing data. A molecular regulatory network of the switchgrass response to alkaline salt stress was preliminarily constructed on the basis of transcriptional regulation and functional genes.Conclusions: The alkaline salt tolerance of switchgrass may be achieved by the regulation of ion homeostasis, transport proteins, detoxification, heat shock proteins, dehydration and sugar metabolism. These findings provide a comprehensive analysis of gene transcription and regulation induced by alkaline salt stress in two switchgrass genotypes and contribute to the understanding of the alkaline salt tolerance mechanism of switchgrass and the improvement of switchgrass germplasm.


2007 ◽  
Vol 27 (14) ◽  
pp. 5214-5224 ◽  
Author(s):  
Jianhua Zhu ◽  
Xinmiao Fu ◽  
Yoon Duck Koo ◽  
Jian-Kang Zhu ◽  
Francis E. Jenney ◽  
...  

ABSTRACT The myristoylated calcium sensor SOS3 and its interacting protein kinase, SOS2, play critical regulatory roles in salt tolerance. Mutations in either of these proteins render Arabidopsis thaliana plants hypersensitive to salt stress. We report here the isolation and characterization of a mutant called enh1-1 that enhances the salt sensitivity of sos3-1 and also causes increased salt sensitivity by itself. ENH1 encodes a chloroplast-localized protein with a PDZ domain at the N-terminal region and a rubredoxin domain in the C-terminal part. Rubredoxins are known to be involved in the reduction of superoxide in some anaerobic bacteria. The enh1-1 mutation causes enhanced accumulation of reactive oxygen species (ROS), particularly under salt stress. ROS also accumulate to higher levels in sos2-1 but not in sos3-1 mutants. The enh1-1 mutation does not enhance sos2-1 phenotypes. Also, enh1-1 and sos2-1 mutants, but not sos3-1 mutants, show increased sensitivity to oxidative stress. These results indicate that ENH1 functions in the detoxification of reactive oxygen species resulting from salt stress by participating in a new salt tolerance pathway that may involve SOS2 but not SOS3.


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.


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.


2019 ◽  
Vol 144 (4) ◽  
pp. 219-235
Author(s):  
He Huang ◽  
Yuting Liu ◽  
Ya Pu ◽  
Mi Zhang ◽  
Silan Dai

Plant growth and development are significantly affected by salt stress. Chrysanthemum lavandulifolium is a halophyte species and one of the ancestors of chrysanthemum (C. ×morifolium). Understanding how this species tolerates salt stress could provide vital insight for clarifying the salt response systems of higher plants, and chrysanthemum-breeding programs could be improved. In this study, salt tolerance was compared among C. lavandulifolium and three chrysanthemum cultivars by physiological experiments, among which C. lavandulifolium and Jinba displayed better tolerance to salt stress than the other two cultivars, whereas Xueshan was a salt-sensitive cultivar. Using the transcriptome database of C. lavandulifolium as a reference, we used digital gene expression technology to analyze the global gene expression changes in C. lavandulifolium seedlings treated with 200 mm NaCl for 12 hours compared with seedlings cultured in normal conditions. In total, 2254 differentially expressed genes (DEGs), including 1418 up-regulated and 836 down-regulated genes, were identified. These DEGs were significantly enriched in 35 gene ontology terms and 29 Kyoto Encyclopedia of Genes and Genomes pathways. Genes related to signal transduction, ion transport, proline biosynthesis, reactive oxygen species scavenging systems, and flavonoid biosynthesis pathways were relevant to the salt tolerance of C. lavandulifolium. Furthermore, comparative gene expression analysis was conducted using reverse transcription polymerase chain reaction to compare the transcriptional levels of significantly up-regulated DEGs in C. lavandulifolium and the salt-sensitive cultivar Xueshan, and species-specific differences were observed. The analysis of one of the DEGs, ClAKT, an important K+ transport gene, was found to enable transgenic Arabidopsis thaliana to absorb K+ and efflux Na+ under salt stress and to absorb K+ under drought stress. The present study investigated potential genes and pathways involved in salt tolerance in C. lavandulifolium and provided a hereditary resource for the confinement of genes and pathways responsible for salt tolerance in this species. This study provided a valuable source of reference genes for chrysanthemum cultivar transgenesis breeding.


2020 ◽  
Author(s):  
Yantong Zhou ◽  
Xiaoxia Tian ◽  
Yong Zhang ◽  
Peichun Mao ◽  
Mingli Zheng ◽  
...  

Abstract As an important nutrient, K+ plays a crucial role in plant stress resistance. It has been reported that the stelar K+ outward rectifying channel (SKOR) is involved in loading K+ into the xylem for its transport from roots to shoots. Elytrigia elongata is a perennial, sparsely distributed, rhizome-type herbaceous plant belonging to the wheatgrass family; it has high salt tolerance. Here, we isolated EeSKOR from decaploid E. elongata and investigated its function in transgenic tobacco. The results showed that EeSKOR was mainly expressed in the roots and was up-regulated with increasing salinity and drought intensity. Overexpression of EeSKOR in plants exposed to salt stress enhanced growth performance, increased SOD activity and chlorophyll content, significantly reduced H2O2 and MDA content, reduced Na+ concentration, and increased K+ concentration in transgenic tobacco plants compared with wild-type (WT) and null vector (Vector) plants. Our findings suggest that transgenic plants overexpressing EeSKOR could enhance K+ transport from the roots to the aboveground parts to maintain K+ steady-state in the aboveground under conditions of salt stress, thereby enhancing tobacco salt tolerance.


Sign in / Sign up

Export Citation Format

Share Document