Root Abscisic Acid Contributes to Defending Photoinibition in Jerusalem Artichoke (Helianthus tuberosus L.) under Salt Stress

The aim of the study was to examine the role of root abscisic acid (ABA) in protecting photosystems and photosynthesis in Jerusalem artichoke against salt stress. Potted plants were pretreated by a specific ABA synthesis inhibitor sodium tungstate and then subjected to salt stress (150 mM NaCl). Tungstate did not directly affect root ABA content and photosynthetic parameters, whereas it inhibited root ABA accumulation and induced a greater decrease in photosynthetic rate under salt stress. The maximal photochemical efficiency of PSII (Fv/Fm) significantly declined in tungstate-pretreated plants under salt stress, suggesting photosystem II (PSII) photoinhibition appeared. PSII photoinhibition did not prevent PSI photoinhibition by restricting electron donation, as the maximal photochemical efficiency of PSI (ΔMR/MR0) was lowered. In line with photoinhibition, elevated H2O2 concentration and lipid peroxidation corroborated salt-induced oxidative stress in tungstate-pretreated plants. Less decrease in ΔMR/MR0 and Fv/Fm indicated that PSII and PSI in non-pretreated plants could maintain better performance than tungstate-pretreated plants under salt stress. Consistently, greater reduction in PSII and PSI reaction center protein abundance confirmed the elevated vulnerability of photosystems to salt stress in tungstate-pretreated plants. Overall, the root ABA signal participated in defending the photosystem’s photoinhibition and protecting photosynthesis in Jerusalem artichoke under salt stress.

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Photosynthetic performance in Eucalyptus clones cultivated in saline soil

Emirates Journal of Food and Agriculture ◽

10.9755/ejfa.2019.v31.i5.1955 ◽

2019 ◽

pp. 368

Author(s):

Jailma Ribeiro de Andrade ◽

Sebastião de Oliveira Maia Júnior ◽

Andrea Francisca da Silva Santos ◽

Vicente Mota da Silva ◽

L.T. Bezerra, J.R.R. da Silva, C.M. Santos, V.M. Ferreira, L. Endres

Keyword(s):

Salt Stress ◽

Block Design ◽

Photosynthetic Pigment ◽

Photochemical Efficiency ◽

Dry Mass ◽

Photosynthetic Performance ◽

Saline Stress ◽

Physiological Indicators ◽

Photochemical Efficiency Of Psii ◽

Randomized Block Design

The aim of this study was to evaluate the photosynthetic performance of Eucalyptus clones with the aim of identifying their tolerance to soil saline stress conditions. The experiment was arranged in a randomized block design with a 3 × 4 factorial arrangement: in five replications, totaling 60 plots, three Eucalyptus clones were used, VC865, I224, and I144, which were exposed to four concentrations of NaCl (0, 1, 2 and 3 g NaCl kg-1 of soil). Clone I144 shows mechanisms of salinity tolerance as smaller reductions in the stomatal conductance, transpiration, photosynthesis, photochemical efficiency of PSII, photosynthetic pigment content and total dry mass. On the other hand, clone I224 presents greater physiological damage, indicating high susceptibility to salt stress, while VC865 shows moderate sensitivity to salinity. Variables related to photosynthetic performance, such as gas exchange, photochemical efficiency of PSII and photosynthetic pigments are potentially reliable physiological indicators for selecting of tolerant Eucalyptus clones to salt stress.

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Comparison of changes in water status and photosynthetic parameters in wild type and abscisic acid-deficient sitiens mutant of tomato (Solanum lycopersicum cv. Rheinlands Ruhm) exposed to sublethal and lethal salt stress

Journal of Plant Physiology ◽

10.1016/j.jplph.2018.11.015 ◽

2019 ◽

Vol 232 ◽

pp. 130-140 ◽

Cited By ~ 5

Author(s):

Péter Poór ◽

Péter Borbély ◽

Zalán Czékus ◽

Zoltán Takács ◽

Attila Ördög ◽

...

Keyword(s):

Abscisic Acid ◽

Salt Stress ◽

Solanum Lycopersicum ◽

Water Status ◽

Photosynthetic Parameters ◽

Wild Type

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Effect of Zinc Priming on Salt Response of Wheat Seedlings: Relieving or Worsening?

Plants ◽

10.3390/plants9111514 ◽

2020 ◽

Vol 9 (11) ◽

pp. 1514

Author(s):

Carmelina Spanò ◽

Stefania Bottega ◽

Lorenza Bellani ◽

Simonetta Muccifora ◽

Carlo Sorce ◽

...

Keyword(s):

Oxidative Stress ◽

Salt Stress ◽

Zno Nanoparticles ◽

Photochemical Efficiency ◽

Saline Stress ◽

Photosynthetic Parameters ◽

Wheat Seedlings ◽

Large Variability ◽

Mode Of Application ◽

Salt Response

In an attempt to alleviate salt-induced damage, the application of ZnO nanoparticles has been suggested. As the use of these particles has also been associated with phytotoxicity, to better clarify the effect of zinc and its possible mitigation of salt stress, we treated wheat seedlings with ZnO (nanoparticles or their bulk-scale counterparts, amended either in the growth medium, NPs and B, or sprayed on the leaves, SPNPs and SPB) with or without subsequent treatment with salt. Growth, photosynthetic parameters, zinc and ion concentration, and in situ and biochemical determination of oxidative stress in wheat leaves and/or in roots were considered. Both Zn and NaCl significantly inhibited growth and induced severe alterations in root morphology. Oxidative stress and damage decreased or increased under ZnO treatment and in saline conditions depending on the organ and on the size and mode of application of particles. In spite of the higher stress conditions often recorded in treated leaves, neither pigment concentration nor photochemical efficiency were decreased. A large variability in the effects of ZnO treatment/priming on seedling salt response was recorded; however, the presence of a cumulative negative effect of priming and salt stress sometimes observed calls for caution in the use of ZnO in protection from saline stress.

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Impact of Drought and Salinity on Sweetgum Tree (Liquidambar styraciflua L.): Understanding Tree Ecophysiological Responses in the Urban Context

Forests ◽

10.3390/f10111032 ◽

2019 ◽

Vol 10 (11) ◽

pp. 1032

Author(s):

Rita Baraldi ◽

Arkadiusz Przybysz ◽

Osvaldo Facini ◽

Lorenzo Pierdonà ◽

Giulia Carriero ◽

...

Keyword(s):

Salt Stress ◽

Stomatal Conductance ◽

Xanthophyll Cycle ◽

Photochemical Efficiency ◽

Photosynthetic Apparatus ◽

Liquidambar Styraciflua ◽

Photosynthetic Parameters ◽

Urban Tree ◽

Isoprene Emission ◽

The Impact

Understanding urban tree responses to drought, salt stress, and co-occurring stresses, as well as the capability to recover afterward, is important to prevent the cited stresses’ negative effects on tree performance and ecological functionality. We investigated the impact of drought and salinity, alone and in combination, on leaf water potential, gas exchange, chlorophyll a fluorescence, xanthophyll cycle pigments, and isoprene emission of the urban tree species Liquidambar styraciflua L. Generally, drought had a rapid negative impact, while the effect of salt stress was more long lasting. Both stressors significantly decreased photosynthesis, transpiration, and stomatal conductance, as well as the maximum quantum efficiency of photosystem II (Fv/Fm) and the photochemical efficiency of PSII (ΦPSII), but increased nonphotochemical quenching (NPQ). Under stress conditions, a strong negative correlation between the PSII efficiency and the xanthophyll cycle pigment composition indicated a nocturnal retention of zeaxanthin and antheraxanthin in a state primed for energy dissipation. Drought and salt stress inhibited isoprene emission from leaves, although its emission was less responsive to stresses than stomatal conductance and photosynthesis. Full recovery of photosynthetic parameters took place after rewatering and washing off of excess salt, indicating that no permanent damage occurred, and suggesting downregulation rather than permanent impairment of the photosynthetic apparatus. Sweetgum trees were capable of withstanding and surviving moderate drought and salt events by activating defense mechanisms conferring tolerance to environmental stresses, without increasing the emission in the atmosphere of the highly reactive isoprene.

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Expression of Genes Related to Plant Hormone Signal Transduction in Jerusalem artichoke (Helianthus tuberosus L.) Seedlings Under Salt Stress

10.20944/preprints202111.0565.v1 ◽

2021 ◽

Author(s):

Yue Yang ◽

Wang Jueyun ◽

Ren Wencai ◽

Zhaosheng Zhou ◽

Long Xiaohua ◽

...

Keyword(s):

Signal Transduction ◽

Abscisic Acid ◽

Salt Stress ◽

Plant Hormone ◽

Jerusalem Artichoke ◽

Helianthus Tuberosus ◽

Rna Seq ◽

Tolerance Mechanisms ◽

Expression Of Genes ◽

Gene Functions

Background: Jerusalem artichoke (Helianthus tuberosus L.) is tolerant to salinity stress and has high economic value. The salt tolerance mechanisms of Jerusalem artichoke are still unclear. Especially in the early stage of Jerusalem artichoke exposure to salt stress, the plant physiology, biochemistry and gene transcription are likely to undergo large changes. Elucidating these changes may be of great significance to understanding the salt tolerance mechanisms of it. Results: We obtained high-quality transcriptome from leaves and roots of Jerusalem artichoke exposed to salinity (300 mM NaCl) for 0 h, 6 h, 12 h, 24 h and 48 h, with 150,129 unigenes and 9023 DEGs (Differentially Expressed Genes). The RNA-seq data were clustered into time-dependent groups (nine clusters each in leaves and roots); gene functions were distributed evenly among the groups convergence. KEGG enrichment analysis showed the genes related to plant hormone signal transduction were enriched in almost all treatment comparisons. Under salt stress, genes belongs to PYL (abscisic acid receptor PYR / PYL family), PP2C (Type 2C protein phosphatases), GH3 (Gretchen Hagen3), ETR (ethylene receptor), EIN2/3 (ethylene-insensitive protein 2/3), JAZ (Genes such as jasmonate ZIM-domain gene) and MYC2 (Transcription factor MYC2) had extremely similar expression patterns. The results of qPCR of 12 randomly selected genes confirmed the accuracy of RNA-seq. Conclusions: Under the impact of high salinity (300mM) environment, Jerusalem artichoke in the seedling stage was difficult to survive for a long time, and the phenotype was severe in the short term. Based on the expression of genes on the time scale, we found that the distribution of gene functions in time is relatively even. Upregulation of the phytohormone signal transduction had a crucial role in the response of Jerusalem artichoke seedlings to salt stress, the genes of abscisic acid, auxin, ethylene, and jasmonic acid had the most obvious change pattern.

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Exogenous putrescine alleviates photoinhibition caused by salt stress through increasing cyclic electron flow in cucumber

10.1101/301762 ◽

2018 ◽

Author(s):

Xinyi Wu ◽

Sheng Shu ◽

Yu Wang ◽

Ruonan Yuan ◽

Shirong Guo

Keyword(s):

Salt Stress ◽

Electron Flow ◽

Critical Role ◽

Photochemical Efficiency ◽

Cyclic Electron Flow ◽

Photochemical Quenching ◽

Photochemical Efficiency Of Psii ◽

High Level ◽

Non Photochemical Quenching ◽

Related Proteins

AbstractWhen plants suffer from abiotic stresses, cyclic electron flow (CEF) is induced for photoprotection. Putrescine (Put), a main polyamine in chloroplasts, plays a critical role in stress tolerance. To elucidate the mechanism of Put regulating CEF for salt-tolerance in cucumber leaves, we measured chlorophyll fluorescence, P700 redox state, ATP and NADPH accumulation and so on. The maximum photochemical efficiency of PSII (Fv/Fm) was not influenced by NaCl and/or Put, but the activity of PSI reaction center (P700) was seriously inhibited by NaCl. Salt stress induced high level of CEF, moreover, NaCl and Put treated plants exhibited much higher CEF activity and ATP accumulation than single salt-treated plants to provide adequate ATP/NADPH ratio for plants growth. Furthermore, Put decreased the trans-membrane proton gradient (ΔpH), accompanied by reducing the pH-dependent non-photochemical quenching (qE) and increasing efficient quantum yield of PSII (Y(II)). The ratio of NADP+/NADPH in salt stressed leaves was significantly increased by Put, indicating that Put relieved over-reduction pressure at PSI accepter side. Taken together, our results suggest that exogenous Put enhances CEF to supply extra ATP for PSI recovery and CO2 assimilation, decreases ΔpH for electron transport related proteins staying active, and enable the non-photochemical quenching transformed into photochemical quenching.

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Effect of Bacillus spp. and Brevibacillus sp. on the Photosynthesis and Redox Status of Solanum lycopersicum

Horticulturae ◽

10.3390/horticulturae7020024 ◽

2021 ◽

Vol 7 (2) ◽

pp. 24

Author(s):

Marino Costa-Santos ◽

Nuno Mariz-Ponte ◽

Maria Celeste Dias ◽

Luísa Moura ◽

Guilhermina Marques ◽

...

Keyword(s):

Solanum Lycopersicum ◽

Intercellular Co2 Concentration ◽

Redox Status ◽

Antioxidant Defenses ◽

Photosynthetic Parameters ◽

Plant Growth Promoting Bacteria ◽

Potted Plants ◽

Chlorophylls A And B ◽

Bacillus Spp ◽

The Impact

Plant-growth-promoting bacteria (PGPB) are gaining attention as a sustainable alternative to current agrochemicals. This study evaluated the impact of three Bacillus spp. (5PB1, 1PB1, FV46) and one Brevibacillus sp. (C9F) on the important crop tomato (Solanum lycopersicum) using the model cv. ‘MicroTom’. The effects of these isolates were assessed on (a) seedlings’ growth and vigor, and (b) adult potted plants. In potted plants, several photosynthetic parameters (chlorophylls (a and b), carotenoids and anthocyanins contents, transpiration rate, stomatal conductance, net CO2 photosynthetic rate, and intercellular CO2 concentration, and on chlorophyll fluorescence yields of light- and dark-adapted leaves)), as well as soluble sugars and starch contents, were quantified. Additionally, the effects on redox status were evaluated. While the growth of seedlings was, overall, not influenced by the strains, some effects were observed on adult plants. The Bacillus safensis FV46 stimulated the content of pigments, compared to C9F. Bacillus zhangzhouensis 5PB1 increased starch levels and was positively correlated with some parameters of the photophosphorylation and the gas exchange phases. Interestingly, Bacillus megaterium 1PB1 decreased superoxide (O2−) content, and B. safensis FV46 promoted non-enzymatic antioxidant defenses, increasing total phenol content levels. These results, conducted on a model cultivar, support the theory that these isolates differently act on tomato plant physiology, and that their activity depends on the age of the plant, and may differently influence photosynthesis. It would now be interesting to analyze the influence of these bacteria using commercial cultivars.

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Exogenous melatonin improves the salt tolerance of cotton by removing active oxygen and protecting photosynthetic organs

BMC Plant Biology ◽

10.1186/s12870-021-03082-7 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Dan Jiang ◽

Bin Lu ◽

Liantao Liu ◽

Wenjing Duan ◽

Yanjun Meng ◽

...

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Oxidative Damage ◽

Photosynthetic Capacity ◽

Photochemical Efficiency ◽

Photochemical Quenching ◽

Plant Tolerance ◽

Signal Molecule ◽

Ion Balance ◽

Photosynthetic System

Abstract Background As damage to the ecological environment continues to increase amid unreasonable amounts of irrigation, soil salinization has become a major challenge to agricultural development. Melatonin (MT) is a pleiotropic signal molecule and indole hormone, which alleviates the damage of abiotic stress to plants. MT has been confirmed to eliminate reactive oxygen species (ROS) by improving the antioxidant system and reducing oxidative damage under adversity. However, the mechanism by which exogenous MT mediates salt tolerance by regulating the photosynthetic capacity and ion balance of cotton seedlings still remains unknown. In this study, the regulatory effects of MT on the photosynthetic system, osmotic modulators, chloroplast, and anatomical structure of cotton seedlings were determined under 0–500 μM MT treatments with salt stress induced by treatment with 150 mM NaCl. Results Salt stress reduces the chlorophyll content, net photosynthetic rate, stomatal conductance, intercellular CO2 concentration, transpiration rate, PSII photochemical efficiency, PSII actual photochemical quantum yield, the apparent electron transfer efficiency, stomata opening, and biomass. In addition, it increases non-photochemical quenching. All of these responses were effectively alleviated by exogenous treatment with MT. Exogenous MT reduces oxidative damage and lipid peroxidation by reducing salt-induced ROS and protects the plasma membrane from oxidative toxicity. MT also reduces the osmotic pressure by reducing the salt-induced accumulation of Na+ and increasing the contents of K+ and proline. Exogenous MT can facilitate stomatal opening and protect the integrity of cotton chloroplast grana lamella structure and mitochondria under salt stress, protect the photosynthetic system of plants, and improve their biomass. An anatomical analysis of leaves and stems showed that MT can improve xylem and phloem and other properties and aides in the transportation of water, inorganic salts, and organic substances. Therefore, the application of MT attenuates salt-induced stress damage to plants. Treatment with exogenous MT positively increased the salt tolerance of cotton seedlings by improving their photosynthetic capacity, stomatal characteristics, ion balance, osmotic substance biosynthetic pathways, and chloroplast and anatomical structures (xylem vessels and phloem vessels). Conclusions Our study attributes help to protect the structural stability of photosynthetic organs and increase the amount of material accumulation, thereby reducing salt-induced secondary stress. The mechanisms of MT-induced plant tolerance to salt stress provide a theoretical basis for the use of MT to alleviate salt stress caused by unreasonable irrigation, fertilization, and climate change.

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