Short-term salt stress in Brassica rapa seedlings causes alterations in auxin metabolism

Pavlović, Iva; Pěnčík, Aleš; Novák, Ondřej; Vujčić, Valerija; Brkanac, Sandra Radić; Lepeduš, Hrvoje; Strnad, Miroslav; Salopek‐Sondi, Branka

doi:10.1016/j.plaphy.2018.01.026

Cited by 47 publications

(34 citation statements)

References 38 publications

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“…The level of salinity tolerance/sensitivity of the selected Brassica crops was determined using the root-growth bioassay described by Pavlović et al (2018a). The effect of NaCl on the seedlings biomass production was evaluated after 7 days of treatments in comparison to the corresponding controls.…”

Section: Methodsmentioning

confidence: 99%

Early Brassica Crops Responses to Salinity Stress: A Comparative Analysis Between Chinese Cabbage, White Cabbage, and Kale

et al. 2019

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Soil salinity is severely affecting crop productivity in many countries, particularly in the Mediterranean area. To evaluate early plant responses to increased salinity and characterize tolerance markers, three important Brassica crops – Chinese cabbage ( Brassica rapa ssp. pekinensis ), white cabbage ( B. oleracea var. capitata ) and kale ( B. oleracea var. acephala ) were subjected to short-term (24 h) salt stress by exposing them to NaCl at concentrations of 50, 100, or 200 mM. Physiological (root growth, photosynthetic performance parameters, and Na + /K + ratio) and biochemical parameters (proline content and lipid peroxidation as indicated by malondialdehyde, MDA, levels) in the plants’ roots and leaves were then measured. Photosynthetic parameters such as the total performance index PI total (describing the overall efficiency of PSI, PSII and the intersystem electron transport chain) appeared to be the most salinity-sensitive parameter and informative stress marker. This parameter was decreased more strongly in Chinese cabbage than in white cabbage and kale. It indicated that salinity reduced the capacity of the photosynthetic system for efficient energy conversion, particularly in Chinese cabbage. In parallel with the photosynthetic impairments, the Na + /K + ratio was highest in Chinese cabbage leaves and lowest in kale leaves while kale root is able to keep high Na + /K + ratio without a significant increase in MDA. Thus Na + /K + ratio, high in root and low in leaves accompanying with low MDA level is an informative marker of salinity tolerance. The crops’ tolerance was positively correlated with levels of the stress hormone abscisic acid (ABA) and negatively correlated with levels of jasmonic acid (JA), and jasmonoyl-L-isoleucine (JA-Ile). Furthermore, salinity induced contrasting changes in levels of the growth-promoting hormones brassinosteroids (BRs). The crop’s tolerance was positively correlated with levels of BR precursor typhasterol while negatively with the active BR brassinolide. Principal Component Analysis revealed correlations in observed changes in phytohormones, biochemical, and physiological parameters. Overall, the results show that kale is the most tolerant of the three species and Chinese cabbage the most sensitive to salt stress, and provide holistic indications of the spectrum of tolerance mechanisms involved.

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Section: Methodsmentioning

confidence: 99%

Early Brassica Crops Responses to Salinity Stress: A Comparative Analysis Between Chinese Cabbage, White Cabbage, and Kale

et al. 2019

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“…acephala ) in relation to sensitivity/tolerance to salinity, identified Chinese cabbage as sensitive, white cabbage as mildly tolerant, and kale as the most tolerant species [22]. We have also shown that plant hormones play an important role in mediating salinity tolerance in the above Brassica crops [22,23]. In this article, we have extended our research and evaluated the effect of salinity on the levels of specialized metabolites in the same Brassica species ( B. rapa spp.…”

Section: Introductionmentioning

confidence: 99%

Involvement of Phenolic Acids in Short-Term Adaptation to Salinity Stress is Species-Specific among Brassicaceae

Linić

Šamec

Grúz

et al. 2019

Plants

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Salinity is a major abiotic stress negatively affecting plant growth and consequently crop production. The effects of short-term salt stress were evaluated on seedlings of three globally important Brassica crops—Chinese cabbage (Brassica rapa ssp. pekinensis), white cabbage (Brassica oleracea var. capitata), and kale (Brassica oleracea var. acephala)—with particular focus on phenolic acids. The physiological and biochemical stress parameters in the seedlings and the levels of three main groups of metabolites (total glucosinolates, carotenoids, and phenolics) and individual phenolic acids were determined. The salt treatments caused a dose-dependent reduction in root growth and biomass and an increase in stress parameters (Na+/K+ ratio, reactive oxygen species (ROS) and glutathione (GSH)) in all seedlings but most prominently in Chinese cabbage. Based on PCA, specific metabolites grouped close to the more tolerant species, white cabbage and kale. The highest levels of phenolic acids, particularly hydroxycinnamic acids, were determined in the more tolerant kale and white cabbage. A reduction in caffeic, salicylic, and 4-coumaric acid was found in Chinese cabbage and kale, and an increase in ferulic acid levels was found in kale upon salinity treatments. Phenolic acids are species-specific among Brassicaceae, and some may participate in stress tolerance. Salt-tolerant varieties have higher levels of some phenolic acids and suffer less from metabolic stress disorders under salinity stress.

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“…(1) Salt stress-activated JA biosynthesis in plants. Elevated JA levels were detected in a number of plant species such as Arabidopsis [52], tomato [53,54], rice [55,56], maize [57], and Brassica rapa [58] when challenged with salt stress, indicating that high levels of JAs accumulated in salt-challenged plants after salt treatment may function as a protection signal in plants against salinity stress. (2) The exogenous application of JA or MeJA to leaves or roots enhances the salt tolerance of plants.…”

Section: Discussionmentioning

confidence: 99%

Interruption of Jasmonic Acid Biosynthesis Causes Differential Responses in the Roots and Shoots of Maize Seedlings against Salt Stress

Ahmad

Cheng

Sheng

et al. 2019

IJMS

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Jasmonates (JAs) together with jasmonic acid and its offshoots are lipid-derived endogenous hormones that play key roles in both developmental processes and different defense responses in plants. JAs have been studied intensively in the past decades for their substantial roles in plant defense comebacks against diverse environmental stresses among model plants. However, the role of this phytohormone has been poorly investigated in the monocotyledonous species against abiotic stresses. In this study, a JA biosynthesis mutant opr7opr8 was used for the investigation of JA roles in the salt stress responses of maize seedlings, whose roots were exposed to 0 to 300 mM NaCl. Foliar stomatal observation showed that opr7opr8 had a larger stomatal aperture than wild type (WT) (B73) under salinity stress, indicating that JA positively regulates guard cell movement under salt stress. The results regarding chlorophyll content and leaf senescence showed that opr7opr8 exhibited delayed leaf senescence under salt stress as compared to WT, indicating that JA plays a role in salt-inducing cell death and subsequent leaf senescence. Moreover, the morphological parameters, including the length of the shoots and roots, and the fresh and dry weights of the shoots and roots, showed that after 7 days of salt treatment, opr7opr8 had heavier and longer shoots than WT but slighter and shorter roots than WT. In addition, ion analysis showed that opr7opr8 accumulated less sodium but more potassium in the leaves than WT but more sodium and less potassium in the roots than WT, suggesting that JA deficiency causes higher salt stress to the roots but less stress to the leaves of the seedlings. Reactive oxygen species (ROS) analysis showed that opr7opr8 produced less H2O2 than WT in the leaves but more H2O2 in the roots under salt treatment, and correspondingly, ROS-scavenging enzymes superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) showed a similar variation, i.e., opr7opr8 has lower enzymatic activities in the shoots but higher activities in the roots than WT under salt treatment. For osmotic adjustment, opr7opr8 produced less proline in the shoots at 100 and 300 mM NaCl treatments but more in the roots than the WT roots under all salt treatments. In addition, the gene expression for abscisic acid (ABA) biosynthesis under salt stress was investigated. Results showed that the expression levels of four key enzymes of ABA biosynthesis, ZEP1, NCED5, AO1, and VP10, were significantly downregulated in the shoots as compared to WT under salt treatment. Putting all the data together, we concluded that JA-deficiency in maize seedlings reduced the salt-stress responses in the shoots but exaggerated the responses in the roots. In addition, endogenous JA acted as a positive regulator for the transportation of sodium ions from the roots to the shoots because the mutant opr7opr8 had a higher level of sodium in the roots but a significantly lower level in the shoots than WT. Furthermore, JA may act as a positive regulator for ABA biosynthesis in the leaves under salt stress.

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Short-term salt stress in Brassica rapa seedlings causes alterations in auxin metabolism

Cited by 47 publications

References 38 publications

Early Brassica Crops Responses to Salinity Stress: A Comparative Analysis Between Chinese Cabbage, White Cabbage, and Kale

Early Brassica Crops Responses to Salinity Stress: A Comparative Analysis Between Chinese Cabbage, White Cabbage, and Kale

Involvement of Phenolic Acids in Short-Term Adaptation to Salinity Stress is Species-Specific among Brassicaceae

Interruption of Jasmonic Acid Biosynthesis Causes Differential Responses in the Roots and Shoots of Maize Seedlings against Salt Stress

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