TY - JOUR A1 - Bazihizina, Nadia A1 - Böhm, Jennifer A1 - Messerer, Maxim A1 - Stigloher, Christian A1 - Müller, Heike M. A1 - Cuin, Tracey Ann A1 - Maierhofer, Tobias A1 - Cabot, Joan A1 - Mayer, Klaus F. X. A1 - Fella, Christian A1 - Huang, Shouguang A1 - Al‐Rasheid, Khaled A. S. A1 - Alquraishi, Saleh A1 - Breadmore, Michael A1 - Mancuso, Stefano A1 - Shabala, Sergey A1 - Ache, Peter A1 - Zhang, Heng A1 - Zhu, Jian‐Kang A1 - Hedrich, Rainer A1 - Scherzer, Sönke T1 - Stalk cell polar ion transport provide for bladder‐based salinity tolerance in Chenopodium quinoa JF - New Phytologist N2 - Chenopodium quinoa uses epidermal bladder cells (EBCs) to sequester excess salt. Each EBC complex consists of a leaf epidermal cell, a stalk cell, and the bladder. Under salt stress, sodium (Na\(^{+}\)), chloride (Cl\(^{−}\)), potassium (K\(^{+}\)) and various metabolites are shuttled from the leaf lamina to the bladders. Stalk cells operate as both a selectivity filter and a flux controller. In line with the nature of a transfer cell, advanced transmission electron tomography, electrophysiology, and fluorescent tracer flux studies revealed the stalk cell’s polar organization and bladder‐directed solute flow. RNA sequencing and cluster analysis revealed the gene expression profiles of the stalk cells. Among the stalk cell enriched genes, ion channels and carriers as well as sugar transporters were most pronounced. Based on their electrophysiological fingerprint and thermodynamic considerations, a model for stalk cell transcellular transport was derived. KW - halophyte KW - polar ion transport KW - quinoa KW - salt tolerance KW - stalk cell Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-287222 VL - 235 IS - 5 SP - 1822 EP - 1835 ER - TY - JOUR A1 - Rasouli, Fatemeh A1 - Kiani-Pouya, Ali A1 - Shabala, Lana A1 - Li, Leiting A1 - Tahir, Ayesha A1 - Yu, Min A1 - Hedrich, Rainer A1 - Chen, Zhonghua A1 - Wilson, Richard A1 - Zhang, Heng A1 - Shabala, Sergey T1 - Salinity effects on guard cell proteome in Chenopodium quinoa JF - International Journal of Molecular Sciences N2 - Epidermal fragments enriched in guard cells (GCs) were isolated from the halophyte quinoa (Chenopodium quinoa Wild.) species, and the response at the proteome level was studied after salinity treatment of 300 mM NaCl for 3 weeks. In total, 2147 proteins were identified, of which 36% were differentially expressed in response to salinity stress in GCs. Up and downregulated proteins included signaling molecules, enzyme modulators, transcription factors and oxidoreductases. The most abundant proteins induced by salt treatment were desiccation-responsive protein 29B (50-fold), osmotin-like protein OSML13 (13-fold), polycystin-1, lipoxygenase, alpha-toxin, and triacylglycerol lipase (PLAT) domain-containing protein 3-like (eight-fold), and dehydrin early responsive to dehydration (ERD14) (eight-fold). Ten proteins related to the gene ontology term “response to ABA” were upregulated in quinoa GC; this included aspartic protease, phospholipase D and plastid-lipid-associated protein. Additionally, seven proteins in the sucrose–starch pathway were upregulated in the GC in response to salinity stress, and accumulation of tryptophan synthase and L-methionine synthase (enzymes involved in the amino acid biosynthesis) was observed. Exogenous application of sucrose and tryptophan, L-methionine resulted in reduction in stomatal aperture and conductance, which could be advantageous for plants under salt stress. Eight aspartic proteinase proteins were highly upregulated in GCs of quinoa, and exogenous application of pepstatin A (an inhibitor of aspartic proteinase) was accompanied by higher oxidative stress and extremely low stomatal aperture and conductance, suggesting a possible role of aspartic proteinase in mitigating oxidative stress induced by saline conditions. KW - quinoa KW - guard cell KW - stomata KW - salt stress KW - proteomics analysis Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-285625 SN - 1422-0067 VL - 22 IS - 1 ER - TY - JOUR A1 - Rasouli, Fatemeh A1 - Kiani-Pouya, Ali A1 - Li, Leiting A1 - Zhang, Heng A1 - Chen, Zhonghua A1 - Hedrich, Rainer A1 - Wilson, Richard A1 - Shabala, Sergey T1 - Sugar beet (Beta vulgaris) guard cells responses to salinity stress: a proteomic analysis JF - International Journal of Molecular Sciences N2 - Soil salinity is a major environmental constraint affecting crop growth and threatening global food security. Plants adapt to salinity by optimizing the performance of stomata. Stomata are formed by two guard cells (GCs) that are morphologically and functionally distinct from the other leaf cells. These microscopic sphincters inserted into the wax-covered epidermis of the shoot balance CO\(_2\) intake for photosynthetic carbon gain and concomitant water loss. In order to better understand the molecular mechanisms underlying stomatal function under saline conditions, we used proteomics approach to study isolated GCs from the salt-tolerant sugar beet species. Of the 2088 proteins identified in sugar beet GCs, 82 were differentially regulated by salt treatment. According to bioinformatics analysis (GO enrichment analysis and protein classification), these proteins were involved in lipid metabolism, cell wall modification, ATP biosynthesis, and signaling. Among the significant differentially abundant proteins, several proteins classified as “stress proteins” were upregulated, including non-specific lipid transfer protein, chaperone proteins, heat shock proteins, inorganic pyrophosphatase 2, responsible for energized vacuole membrane for ion transportation. Moreover, several antioxidant enzymes (peroxide, superoxidase dismutase) were highly upregulated. Furthermore, cell wall proteins detected in GCs provided some evidence that GC walls were more flexible in response to salt stress. Proteins such as L-ascorbate oxidase that were constitutively high under both control and high salinity conditions may contribute to the ability of sugar beet GCs to adapt to salinity by mitigating salinity-induced oxidative stress. KW - guard cells KW - stomata KW - sugar beet KW - salt stress KW - proteomic Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-285765 SN - 1422-0067 VL - 21 IS - 7 ER - TY - JOUR A1 - Zhu, Min A1 - Shabala, Lana A1 - Cuin, Tracey A A1 - Huang, Xin A1 - Zhou, Meixue A1 - Munns, Rana A1 - Shabala, Sergey T1 - Nax loci affect SOS1-like Na\(^{+}\)/H\(^{+}\) exchanger expression and activity in wheat JF - Journal of Experimental Botany N2 - Salinity stress tolerance in durum wheat is strongly associated with a plant’s ability to control Na\(^{+}\) delivery to the shoot. Two loci, termed Nax1 and Nax2, were recently identified as being critical for this process and the sodium transporters HKT1;4 and HKT1;5 were identified as the respective candidate genes. These transporters retrieve Na\(^{+}\) from the xylem, thus limiting the rates of Na\(^{+}\) transport from the root to the shoot. In this work, we show that the Nax loci also affect activity and expression levels of the SOS1-like Na\(^{+}\)/H\(^{+}\) exchanger in both root cortical and stelar tissues. Net Na\(^{+}\) efflux measured in isolated steles from salt-treated plants, using the non-invasive ion flux measuring MIFE technique, decreased in the sequence: Tamaroi (parental line)>Nax1=Nax2>Nax1:Nax2 lines. This efflux was sensitive to amiloride (a known inhibitor of the Na\(^{+}\)/H\(^{+}\) exchanger) and was mirrored by net H\(^{+}\) flux changes. TdSOS1 relative transcript levels were 6–10-fold lower in Nax lines compared with Tamaroi. Thus, it appears that Nax loci confer two highly complementary mechanisms, both of which contribute towards reducing the xylem Na\(^{+}\) content. One enhances the retrieval of Na\(^{+}\) back into the root stele via HKT1;4 or HKT1;5, whilst the other reduces the rate of Na\(^{+}\) loading into the xylem via SOS1. It is suggested that such duality plays an important adaptive role with greater versatility for responding to a changing environment and controlling Na\(^{+}\) delivery to the shoot. KW - HKT transporter KW - potassium KW - salinity stress KW - sequestration KW - sodium KW - xylem loading Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-150236 VL - 67 IS - 3 ER - TY - JOUR A1 - Zhu, Min A1 - Shabala, Lana A1 - Cuin, Tracey A. A1 - Huang, Xin A1 - Zhou, Meixue A1 - Munns, Rana A1 - Shabala, Sergey T1 - Nax loci affect SOS1-like Na\(^+\)/H\(^+\) exchanger expression and activity in wheat JF - Journal of Experimental Botany N2 - Salinity stress tolerance in durum wheat is strongly associated with a plant's ability to control Na\(^+\) delivery to the shoot. Two loci, termed Nax1 and Nax2, were recently identified as being critical for this process and the sodium transporters HKT1;4 and HKT1; 5 were identified as the respective candidate genes. These transporters retrieve Na\(^+\) from the xylem, thus limiting the rates of Na\(^+\) transport from the root to the shoot. In this work, we show that the Nax loci also affect activity and expression levels of the SOS1-like Na\(^+\)/H\(^+\) exchanger in both root cortical and stelar tissues. Net Na\(^+\) efflux measured in isolated steles from salt-treated plants, using the non-invasive ion flux measuring MIFE technique, decreased in the sequence: Tamaroi (parental line)>Nax1=Nax2>Nax1:Nax2 lines. This efflux was sensitive to amiloride (a known inhibitor of the Na\(^+\)/H\(^+\) exchanger) and was mirrored by net H\(^+\) flux changes. TdSOS1 relative transcript levels were 6-10-fold lower in Nax lines compared with Tamaroi. Thus, it appears that Nax loci confer two highly complementary mechanisms, both of which contribute towards reducing the xylem Na\(^+\) content. One enhances the retrieval of Na\(^+\) back into the root stele via HKT1;4 or HKT1;5, whilst the other reduces the rate of Na\(^+\) loading into the xylem via SOS1. It is suggested that such duality plays an important adaptive role with greater versatility for responding to a changing environment and controlling Na\(^+\) delivery to the shoot. KW - HKT transporter KW - potassium KW - salinity stress KW - sequestration KW - sodium KW - xylem loading Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-190908 VL - 67 IS - 3 ER - TY - JOUR A1 - Böhm, Jennifer A1 - Scherzer, Sönke A1 - Krol, Elzbieta A1 - Kreuzer, Ines A1 - von Meyer, Katharina A1 - Lorey, Christian A1 - Mueller, Thomas D. A1 - Shabala, Lana A1 - Monte, Isabel A1 - Salano, Roberto A1 - Al-Rasheid, Khaled A. S. A1 - Rennenberg, Heinz A1 - Shabala, Sergey A1 - Neher, Erwin A1 - Hedrich, Rainer T1 - The Venus Flytrap Dionaea muscipula Counts Prey-Induced Action Potentials to Induce Sodium Uptake JF - Current Biology N2 - Carnivorous plants, such as the Venus flytrap (Dionaea muscipula), depend on an animal diet when grown in nutrient-poor soils. When an insect visits the trap and tilts the mechanosensors on the inner surface, action potentials (APs) are fired. After a moving object elicits two APs, the trap snaps shut, encaging the victim. Panicking preys repeatedly touch the trigger hairs over the subsequent hours, leading to a hermetically closed trap, which via the gland-based endocrine system is flooded by a prey-decomposing acidic enzyme cocktail. Here, we asked the question as to how many times trigger hairs have to be stimulated (e.g., now many APs are required) for the flytrap to recognize an encaged object as potential food, thus making it worthwhile activating the glands. By applying a series of trigger-hair stimulations, we found that the touch hormone jasmonic acid (JA) signaling pathway is activated after the second stimulus, while more than three APs are required to trigger an expression of genes encoding prey-degrading hydrolases, and that this expression is proportional to the number of mechanical stimulations. A decomposing animal contains a sodium load, and we have found that these sodium ions enter the capture organ via glands. We identified a flytrap sodium channel DmHKT1 as responsible for this sodium acquisition, with the number of transcripts expressed being dependent on the number of mechano-electric stimulations. Hence, the number of APs a victim triggers while trying to break out of the trap identifies the moving prey as a struggling Na+-rich animal and nutrition for the plant. KW - Venusfliegenfalle KW - Dionaea muscipula Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-128054 VL - 26 IS - 3 ER - TY - JOUR A1 - Böhm, Jennifer A1 - Scherzer, Sönke A1 - Krol, Elzbieta A1 - Kreuzer, Ines A1 - von Meyer, Katharina A1 - Lorey, Christian A1 - Mueller, Thomas D. A1 - Shabala, Lana A1 - Monte, Isabel A1 - Solano, Roberto A1 - Al-Rasheid, Khaled A. S. A1 - Rennenberg, Heinz A1 - Shabala, Sergey A1 - Neher, Erwin A1 - Hedrich, Rainer T1 - The Venus flytrap Dionaea muscipula counts prey-induced action potentials to induce sodium uptake JF - Current Biology N2 - Carnivorous plants, such as the Venus flytrap (Dionaea muscipula), depend on an animal diet when grown in nutrient-poor soils. When an insect visits the trap and tilts the mechanosensors on the inner surface, action potentials (APs) are fired. After a moving object elicits two APs, the trap snaps shut, encaging the victim. Panicking preys repeatedly touch the trigger hairs over the subsequent hours, leading to a hermetically closed trap, which via the gland-based endocrine system is flooded by a prey-decomposing acidic enzyme cocktail. Here, we asked the question as to how many times trigger hairs have to be stimulated (e.g., now many APs are required) for the flytrap to recognize an encaged object as potential food, thus making it worthwhile activating the glands. By applying a series of trigger-hair stimulations, we found that the touch hormone jasmonic acid (JA) signaling pathway is activated after the second stimulus, while more than three APs are required to trigger an expression of genes encoding prey-degrading hydrolases, and that this expression is proportional to the number of mechanical stimulations. A decomposing animal contains a sodium load, and we have found that these sodium ions enter the capture organ via glands. We identified a flytrap sodium channel DmHKT1 as responsible for this sodium acquisition, with the number of transcripts expressed being dependent on the number of mechano-electric stimulations. Hence, the number of APs a victim triggers while trying to break out of the trap identifies the moving prey as a struggling Na\(^+\)-rich animal and nutrition for the plant. KW - jasmonic acid biosynthesis KW - gene expression KW - signal transduction KW - transporters KW - Arabidopsis Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-190870 VL - 26 IS - 3 ER -