scholarly journals Salt acclimation induced salt tolerance in wild-type and abscisic acid-deficient mutant barley

2019 ◽  
Vol 65 (No. 10) ◽  
pp. 516-521 ◽  
Author(s):  
Zhiyu Zuo ◽  
Junhong Guo ◽  
Caiyun Xin ◽  
Shengqun Liu ◽  
Hanping Mao ◽  
...  

Salt acclimation is a process to enhance salt tolerance in plants. The salt acclimation induced salt tolerance was investigated in a spring barley (Hordeum vulgare L.) cv. Steptoe (wild type, WT) and its abscisic acid (ABA)-deficient mutant Az34. Endogenesis ABA concentration in leaf was significantly increased by salt stress in WT, while it was not affected in Az34. Under salt stress, the salt acclimated Az34 plants had 14.8% lower total soluble sugar concentration and 93.7% higher sodium (Na) concentration in leaf, compared with salt acclimated WT plants. The acclimated plants had significantly higher leaf water potential and osmotic potential than non-acclimated plants in both WT and Az34 under salt stress. The salt acclimation enhanced the net photosynthetic rate (by 22.9% and 12.3%) and the maximum quantum yield of PS II (22.7% and 22.0%) in WT and Az34 under salt stress. However, the stomatal conductance in salt acclimated Az34 plants was 28.9% lower than WT under salt stress. Besides, the guard cell pair width was significantly higher in salt acclimated Az34 plants than that in WT plants. The results indicated that the salt acclimated WT plants showed a higher salt tolerance than Az34 plants, suggesting that ABA deficiency has a negative effect on the salt acclimation induced salt tolerance in barley.

2021 ◽  
Vol 67 (No. 1) ◽  
pp. 26-32
Author(s):  
Zhiyu Zuo ◽  
Fan Ye ◽  
Zongshuai Wang ◽  
Shuxin Li ◽  
Hui Li ◽  
...  

Salt acclimation can promote the tolerance of wheat plants to the subsequent salt stress, which may be related to the responses of the photosynthetic apparatus. The chlorophyl (Chl) b-deficient mutant wheat ANK 32B and its wild type (WT) were firstly saltly acclimated with 30 mmol NaCl for 12 days, then subsequently subjected to 6-day salt stress (500 mmol NaCl). The ANK 32B mutant plants had lower Chl b concentration, which was manifested in the lower total Chl concentration, higher ratio of Chl a/b and in reduced photosynthetic activity (P<sub>n</sub>). The effect of salt acclimation was manifested mainly after salt stress. Compared to non-acclimated plants, the salt acclimation increased the leaf water potential, osmotic potential (Ψ<sub>o</sub>) and K concentration, while decreased the amount of Na<sup>+</sup> and H<sub>2</sub>O<sub>2</sub> in WT and ANK 32B under salt stress, except for Ψ<sub>o</sub> in ANK 32B. In addition, the salt acclimation enhanced the APX (ascorbate peroxidase) activity by 10.55% and 33.69% in WT and ANK 32B under salt stress, respectively. Compared to the genotypes, under salt stress, the Ψ<sub>o</sub>, F<sub>v</sub>/F<sub>m</sub>, P<sub>n</sub> and g<sub>s</sub> of mutant plants were 5.60, 17.62, 46.73 and 26.41% lower than that of WT, respectively. These results indicated that although the salt acclimation could alleviate the negative consequences of salt stress, it is mainly manifested in the WT, and the ANK 32B plants had lower salt tolerance than WT plants, suggesting that lower Chl b concentration has a negative effect on the salt acclimation induced salt tolerance in wheat.  


2020 ◽  
Vol 21 (9) ◽  
pp. 3334 ◽  
Author(s):  
Kerstin Duscha ◽  
Cristina Martins Rodrigues ◽  
Maria Müller ◽  
Ruth Wartenberg ◽  
Larry Fliegel ◽  
...  

The plasma membrane transporter SOS1 (SALT-OVERLY SENSITIVE1) is vital for plant survival under salt stress. SOS1 activity is tightly regulated, but little is known about the underlying mechanism. SOS1 contains a cytosolic, autoinhibitory C-terminal tail (abbreviated as SOS1 C-term), which is targeted by the protein kinase SOS2 to trigger its transport activity. Here, to identify additional binding proteins that regulate SOS1 activity, we synthesized the SOS1 C-term domain and used it as bait to probe Arabidopsis thaliana cell extracts. Several 14-3-3 proteins, which function in plant salt tolerance, specifically bound to and interacted with the SOS1 C-term. Compared to wild-type plants, when exposed to salt stress, Arabidopsis plants overexpressing SOS1 C-term showed improved salt tolerance, significantly reduced Na+ accumulation in leaves, reduced induction of the salt-responsive gene WRKY25, decreased soluble sugar, starch, and proline levels, less impaired inflorescence formation and increased biomass. It appears that overexpressing SOS1 C-term leads to the sequestration of inhibitory 14-3-3 proteins, allowing SOS1 to be more readily activated and leading to increased salt tolerance. We propose that the SOS1 C-term binds to previously unknown proteins such as 14-3-3 isoforms, thereby regulating salt tolerance. This finding uncovers another regulatory layer of the plant salt tolerance program.


2017 ◽  
Vol 63 (No. 7) ◽  
pp. 307-314 ◽  
Author(s):  
Wang Zongshuai ◽  
Li Xiangnan ◽  
Zhu Xiancan ◽  
Liu Shengqun ◽  
Song Fengbin ◽  
...  

High salt stress significantly depresses carbon assimilation and plant growth in wheat (Triticum aestivum L.). Salt acclimation can enhance the tolerance of wheat plants to salt stress. Priming with abscisic acid (1 mmol ABA) was applied during the salt acclimation (30 mmol NaCl) process to investigate its effects on the tolerance of wheat to subsequent salt stress (500 mmol NaCl). The results showed that priming with ABA modulated the leaf ABA concentration to maintain better water status in salt acclimated wheat plants. Also, the ABA priming drove the antioxidant systems to protect photosynthetic electron transport in salt acclimated plants against subsequent salt stress, hence improving the carbon assimilation in wheat. It suggested that salt acclimation induced salt tolerance could be improved by abscisic acid priming in wheat.


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.


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.


HortScience ◽  
2015 ◽  
Vol 50 (10) ◽  
pp. 1518-1523 ◽  
Author(s):  
Shanshan Sun ◽  
Mengying An ◽  
Liebao Han ◽  
Shuxia Yin

Perennial ryegrass (Lolium perenne L.) is a widely used turfgrass. In this study, the effect of exogenously applied 24-epibrassinolide (EBR) on salt stress tolerance of perennial ryegrass was investigated. The results indicated that pretreatment with four concentrations of EBR (0, 0.1, 10, 1000 nM) improved salt tolerance of perennial ryegrass. Exogenous EBR treatment decreased electrolyte leakage (EL), malondialdehyde (MDA), and H2O2 contents and enhanced the leaf relative water content (RWC), proline, soluble sugar, and soluble protein content under salt stress condition. Meanwhile, EBR reduced the accumulation of Na+ and increased K+, Ca2+, and Mg2+ contents in leaves after salt treatment. Moreover, EBR pretreatment also increased superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) activity, as well as ascorbic acid (AsA) and glutathione contents. These results suggested that EBR improved salt tolerance by enhancing osmotic adjustment and antioxidant defense systems in perennial ryegrass.


2016 ◽  
Vol 61 (3) ◽  
pp. 328-339 ◽  
Author(s):  
Xiangnan Li ◽  
Dun-Xian Tan ◽  
Dong Jiang ◽  
Fulai Liu

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
G. H. Yu ◽  
X. Zhang ◽  
H. X. Ma

The SbPIP1 gene is a new member of the plasma membrane major intrinsic gene family cloned from the euhalophyteSalicornia bigeloviiTorr. In order to understand the physiological responses in plants that are mediated by the SbPIP1 gene, SbPIP1-overexpressing wheat lines and WT plants of the wheat cv. Ningmai 13 were treated with salt stress. Several physiological parameters, such as the proline content, the malondialdehyde (MDA) content, and the content of soluble sugars and proteins, were compared between SbPIP1-transformed lines and WT plants under normal growth or salt stress conditions. The results indicate that overexpression of the SbPIP1 gene can increase the accumulation of the osmolyte proline, decrease the MDA content, and enhance the soluble sugar biosynthesis in the early period but has no influence on the regulation of soluble protein biosynthesis in wheat. The results suggest that SbPIP1 contributes to salt tolerance by facilitating the accumulation of the osmolyte proline, increasing the antioxidant response, and increasing the biosynthesis of soluble sugar in the early period. These results indicate SbPIP1 plays an important role in the salt stress response. Overexpression of SbPIP1 might be used to improve the salt tolerance of important crop plants.


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