Melatonin Promotes SGT1-Involved Signals to Ameliorate Drought Stress Adaption in Rice

Drought has become one of the environmental threats to agriculture and food security. Applications of melatonin (MT) serve as an effective way to alleviate drought stress, but the underlying mechanism remains poorly understood. Here, we found that foliar spray of 100-µM MT greatly mitigated the severe drought stress-induced damages in rice seedlings, including improved survival rates, enhanced antioxidant system, and adjusted osmotic balance. However, mutation of the suppressor of the G2 allele of skp1 (OsSGT1) and ABSCISIC ACID INSENSITIVE 5 (OsABI5) abolished the effects of MT. Furthermore, the upregulated expression of OsABI5 was detected in wild type (WT) under drought stress, irrespective of MT treatment, whereas OsABI5 was significantly downregulated in sgt1 and sgt1abi5 mutants. In contrast, no change of the OsSGT1 expression level was detected in abi5. Moreover, mutation of OsSGT1 and OsABI5 significantly suppressed the expression of genes associated with the antioxidant system. These results suggested that the functions of OsSGT1 in the MT-mediated alleviation of drought stress were associated with the ABI5-mediated signals. Collectively, we demonstrated that OsSGT1 was involved in the drought response of rice and that melatonin promoted SGT1-involved signals to ameliorate drought stress adaption.

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Foliar Sprayed Green Zinc Oxide Nanoparticles Mitigate Drought-Induced Oxidative Stress in Tomato

Plants ◽

10.3390/plants10112400 ◽

2021 ◽

Vol 10 (11) ◽

pp. 2400

Author(s):

Manal El-Zohri ◽

Naseem A. Al-Wadaani ◽

Sameera O. Bafeel

Keyword(s):

Oxidative Stress ◽

Zinc Oxide ◽

Drought Stress ◽

Zinc Oxide Nanoparticles ◽

Foliar Spray ◽

Oxide Nanoparticles ◽

Severe Drought ◽

Zno Nps ◽

Drought Conditions ◽

Tomato Growth

This study explored the effectiveness of green zinc oxide nanoparticles (ZnO-NPs) foliar spray on tomato growth and oxidative stress relief under drought conditions. Tomato plant subjected to four water regimes (100, 75, 50, and 25% FC), and in the same while seedlings were sprayed with 25, 50, and 100 mg/L green ZnO-NPs. The results showed that tomato growth parameters reduced significantly by increasing drought stress levels, while ZnO-NPs enhanced plant growth under all studied drought levels. Out of three ZnO-NPs concentrations tested, 25 and 50 mg/L ZnO-NPs proved to be the optimum treatments for alleviating drought stress. They increased shoot and root biomass compared to untreated controls. Application of 25 and 50 mg/L ZnO-NPs enhanced shoot dry weight by about 2–2.5-fold, respectively, under severe drought conditions (25%) compared to ZnO-NPs untreated plants. The application of 25 and 50 mg/L green ZnO-NPs decreased the drought-induced oxidative stress as indicated by the reduction in malondialdehyde and hydrogen peroxide concentrations compared to untreated controls. While 100 mg/L ZnO-NPs further increased oxidative stress. The beneficial effects of ZnO-NPs were evident in the plants’ defensive state, in which the concentration of ascorbic acid, free phenols, and the activity of superoxide dismutase, catalase, and ascorbate peroxidase were maintained at higher levels compared to NPs-untreated plants. At severe drought conditions, 25 mg/L ZnO-NPs induced SOD, CAT, and APX activity by about 3.99-, 3.23-, and 2.82-fold of their corresponding controls, respectively. Likewise, at 25% FC, SOD, CAT, and APX activity increased with 50 mg/L ZnO-NPs by about 4.58-, 3.57-, and 3.25-fold consecutively compared with their respective controls. Therefore, foliar use of green ZnO-NPs at lower concentrations might be suggested as an efficient way for enhancing tomato tolerance to drought stress.

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Improved Drought Tolerance by AMF Inoculation in Maize (Zea mays) Involves Physiological and Biochemical Implications

Plants ◽

10.3390/plants8120579 ◽

2019 ◽

Vol 8 (12) ◽

pp. 579 ◽

Cited By ~ 12

Author(s):

Naheeda Begum ◽

Muhammad Abass Ahanger ◽

Yunyun Su ◽

Yafang Lei ◽

Nabil Sabet A. Mustafa ◽

...

Keyword(s):

Zea Mays ◽

Drought Stress ◽

Antioxidant System ◽

Membrane Damage ◽

Mycorrhizal Fungus ◽

Carotenoid Content ◽

Severe Drought ◽

Effects Of Drought ◽

Amf Inoculation

The role of arbuscular mycorrhizal fungus (AMF, Glomus versiforme) in amelioration of drought-induced effects on growth and physio-biochemical attributes in maize (Zea mays L.) was studied. Maize plants were exposed to two drought regimes, i.e., moderate drought (MD) and severe drought (SD), with and without AMF inoculation. Drought at both levels reduced plant height, and chlorophyll and carotenoid content, thereby impeding photosynthesis. In addition, drought stress enhanced the generation of toxic reactive oxygen species (ROS), including H2O2, resulting in membrane damage reflected as increased electrolyte leakage and lipid peroxidation. Such negative effects were much more apparent under SD conditions that those of MD and the control, however, AMF inoculation significantly ameliorated the deleterious effects of drought-induced oxidative damage. Under control conditions, inoculation of AMF increased growth and photosynthesis by significantly improving chlorophyll content, mineral uptake and assimilation. AMF inoculation increased the content of compatible solutes, such as proline, sugars and free amino acids, assisting in maintaining the relative water content. Up-regulation of the antioxidant system was obvious in AMF-inoculated plants, thereby mediating quick alleviation of oxidative effects of drought through elimination of ROS. In addition, AMF mediated up-regulation of the antioxidant system contributed to maintenance of redox homeostasis, leading to protection of major metabolic pathways, including photosynthesis, as observed in the present study. Total phenols increased due to AMF inoculation under both MD and SD conditions. The present study advocates the beneficial role of G. versiforme inoculation in maize against drought stress.

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Is seaweed extract an elicitor compound? Changing proline content in drought-stressed bean plants

Comunicata Scientiae ◽

10.14295/cs.v9i2.2134 ◽

2018 ◽

Vol 9 (2) ◽

pp. 292-297 ◽

Cited By ~ 9

Author(s):

Marcia E.A. Carvalho ◽

Paulo R.C. Castro ◽

Salete A. Gaziola ◽

Ricardo A. Azevedo

Keyword(s):

Drought Stress ◽

Phaseolus Vulgaris ◽

Foliar Spray ◽

Antioxidant Response ◽

Proline Content ◽

Seaweed Extract ◽

Severe Drought ◽

Bean Plants ◽

Crop Development ◽

Soil Irrigation

Abiotic stresses negatively affect crop development and yield. However, the use of seaweed extracts can alleviate production losses through improvement of the antioxidant system and synthesis of compatible osmolytes. The aim of this study was to assess the effects of Ascophyllum nodosum extract on antioxidant response and yield of common bean plants (Phaseolus vulgaris) under drought stress. Therefore, two methods of application (foliar spray and soil irrigation) and two doses (5 and 10 mL L-1) were tested, whereas untreated plants were used as control. There were no significant differences in malondialdehyde and hydrogen peroxide contents among treatments, indicating that application of seaweed extract did not change the oxidative status in treated plants when compared to the control ones. On the other hand, the use of seaweed extract increased proline content even prior to drought stress (46.3 to 145.4% when compared to the control), and this increment remained until the 10th day of stress (from 60.1 to 201.7% over the reference plants), supporting early evidences that A. nodosum extract is a plant elicitor. The yield parameters were not affected by the extract, probably due to the severe drought stress which plants were submitted. The results suggest that A. nodosum extract affects proline metabolism in Phaseolus vulgaris plants, making the synthesis of this osmolyte more responsive to drought stress because seaweed-treated plants presented a higher proline content than the control ones during the exposure to water deficit.

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Dynamic histone acetylation in floral volatile synthesis and emission in petunia flowers

Journal of Experimental Botany ◽

10.1093/jxb/erab072 ◽

2021 ◽

Author(s):

Ryan M Patrick ◽

Xing-Qi Huang ◽

Natalia Dudareva ◽

Ying Li

Keyword(s):

Transcriptional Activation ◽

Metabolic Pathways ◽

Transcriptional Repression ◽

Metabolic Networks ◽

Underlying Mechanism ◽

Expression Of Genes ◽

Genome Wide ◽

Chemical Inhibitors ◽

Volatile Organic ◽

Floral Volatile

Abstract Biosynthesis of secondary metabolites relies on primary metabolic pathways to provide precursors, energy, and cofactors, thus requiring coordinated regulation of primary and secondary metabolic networks. However, to date, it remains largely unknown how this coordination is achieved. Using Petunia hybrida flowers, which emit high levels of phenylpropanoid/benzenoid volatile organic compounds (VOCs), we uncovered genome-wide dynamic deposition of histone H3 lysine 9 acetylation (H3K9ac) during anthesis as an underlying mechanism to coordinate primary and secondary metabolic networks. The observed epigenome reprogramming is accompanied by transcriptional activation at gene loci involved in primary metabolic pathways that provide precursor phenylalanine, as well as secondary metabolic pathways to produce volatile compounds. We also observed transcriptional repression among genes involved in alternative phenylpropanoid branches that compete for metabolic precursors. We show that GNAT family histone acetyltransferase(s) (HATs) are required for the expression of genes involved in VOC biosynthesis and emission, by using chemical inhibitors of HATs, and by knocking down a specific HAT gene, ELP3, through transient RNAi. Together, our study supports that regulatory mechanisms at chromatin level may play an essential role in activating primary and secondary metabolic pathways to regulate VOC synthesis in petunia flowers.

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Role of Suillus placidus in Improving the Drought Tolerance of Masson Pine (Pinus massoniana Lamb.) Seedlings

Forests ◽

10.3390/f12030332 ◽

2021 ◽

Vol 12 (3) ◽

pp. 332

Author(s):

Min Li ◽

Haoyun Wang ◽

Xizhou Zhao ◽

Zhongke Lu ◽

Xueguang Sun ◽

...

Keyword(s):

Drought Stress ◽

Defense Mechanism ◽

Southern China ◽

Dry Weight ◽

Pinus Massoniana ◽

Photosynthetic Performance ◽

Ectomycorrhizal Fungus ◽

Severe Drought ◽

Masson Pine ◽

Pine Seedlings

Masson pine is an important afforestation species in southern China, where seasonal drought is common. The present study focused on the effects of Suillus placidus, an ectomycorrhizal fungus, inoculation on the growth and physiological and biochemical performance of masson pine seedlings under four different watering treatments (well-watered, mild drought, moderate drought, and severe drought) to evaluate the symbiotic relationship between S. placidus and masson pine seedlings. Ectomycorrhizal-inoculated (ECM) and non-inoculated (NM) seedlings were grown in pots and maintained for 60 days using the weighing method. Results showed that seedlings’ growth, dry weight, RWC, chlorophyll content, PSII efficiency, and photosynthesis decreased as drought stress intensified in both ECM and NM plants. This suggests that drought stress significantly limits the growth and photosynthetic performance of masson pine seedlings. Nevertheless, increased An/gs and proline contents in both NM and ECM prevented oxidative damage caused by drought stress. In addition, increased peroxidase (POD) activity is an essential defense mechanism of ECM seedling under drought stress. Compared with NM, ECM seedlings showed faster growth, higher RWC, and photosynthetic performance, and lower lipid peroxidation in cell membranes under drought stress, as indicated by higher POD activity and lower proline and malondialdehyde (MDA). Our experiment found that S. placidus inoculation can enhance the drought resistance of masson pine seedlings by increasing antioxidant enzyme activity, water use efficiency, and proline content, thereby enhancing growth under water-deficiency conditions. S. placidus can be used to cultivate high-quality seedlings and improve their survival in regions that experience seasonal droughts.

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Spermine: Its Emerging Role in Regulating Drought Stress Responses in Plants

Cells ◽

10.3390/cells10020261 ◽

2021 ◽

Vol 10 (2) ◽

pp. 261

Author(s):

Md. Mahadi Hasan ◽

Milan Skalicky ◽

Mohammad Shah Jahan ◽

Md. Nazmul Hossain ◽

Zunaira Anwar ◽

...

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Stress Responses ◽

Abiotic Stresses ◽

Defense Mechanisms ◽

Antioxidant Defense ◽

Severe Drought ◽

New Information ◽

Effects Of Drought

In recent years, research on spermine (Spm) has turned up a lot of new information about this essential polyamine, especially as it is able to counteract damage from abiotic stresses. Spm has been shown to protect plants from a variety of environmental insults, but whether it can prevent the adverse effects of drought has not yet been reported. Drought stress increases endogenous Spm in plants and exogenous application of Spm improves the plants’ ability to tolerate drought stress. Spm’s role in enhancing antioxidant defense mechanisms, glyoxalase systems, methylglyoxal (MG) detoxification, and creating tolerance for drought-induced oxidative stress is well documented in plants. However, the influences of enzyme activity and osmoregulation on Spm biosynthesis and metabolism are variable. Spm interacts with other molecules like nitric oxide (NO) and phytohormones such as abscisic acid, salicylic acid, brassinosteroids, and ethylene, to coordinate the reactions necessary for developing drought tolerance. This review focuses on the role of Spm in plants under severe drought stress. We have proposed models to explain how Spm interacts with existing defense mechanisms in plants to improve drought tolerance.

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Mapping QTLs for yield components and chlorophyll a fluorescence parameters in wheat under three levels of water availability

Plant Genetic Resources ◽

10.1017/s1479262111000207 ◽

2011 ◽

Vol 9 (2) ◽

pp. 291-295 ◽

Cited By ~ 24

Author(s):

Ilona Czyczyło-Mysza ◽

Izabela Marcińska ◽

Edyta Skrzypek ◽

Małgorzata Chrupek ◽

Stanisław Grzesiak ◽

...

Keyword(s):

Drought Stress ◽

Chlorophyll A ◽

Chlorophyll A Fluorescence ◽

Wheat Yield ◽

Dry Weight ◽

Interval Mapping ◽

Main Stem ◽

Severe Drought ◽

Single Marker Analysis ◽

Fluorescence Parameters

Drought is one of the major factors limiting wheat yield in many developing countries worldwide. Parameters of chlorophyll a fluorescence kinetics under drought stress conditions have been used to characterize dehydration tolerance in wheat. In the present study, a set of 94 doubled haploid lines obtained from Chinese Spring × SQ1 (CSDH), mapped with 450 markers, was evaluated for yield (grain dry weight/main stem ear), number of grains/main stem ear (NG) and chlorophyll a fluorescence parameters (FC) under moderate and severe drought stress, and compared with results for well-watered plants. quantitative trait loci (QTLs) were identified using Windows QTLCartographer version 2.5 software and the results were analysed using single-marker analysis (SMA) and composite interval mapping (CIM). Analysis using SMA and CIM showed mostly similar QTLs for all traits, though more QTLs were identified by SMA than by CIM. The genetic control of yield, NG and FC varied considerably between drought-stressed and non-stressed plants. Although no major QTL co-locations were found for yield and FC using CIM, the co-location of QTLs for NG, yield and Fv/Fm in drought-stressed plants was observed on chromosome 5A using SMA.

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Effect of 28-homobrassinolide on the drought stress-induced changes in photosynthesis and antioxidant system of Brassica juncea L.

Acta Physiologiae Plantarum ◽

10.1007/s11738-009-0302-7 ◽

2009 ◽

Vol 31 (5) ◽

pp. 889-897 ◽

Cited By ~ 62

Author(s):

Q. Fariduddin ◽

S. Khanam ◽

S. A. Hasan ◽

B. Ali ◽

S. Hayat ◽

...

Keyword(s):

Drought Stress ◽

Brassica Juncea ◽

Antioxidant System ◽

Induced Changes

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Proteome Analysis of Date Palm (Phoenix dactylifera L.) under Severe Drought and Salt Stress

International Journal of Genomics ◽

10.1155/2016/7840759 ◽

2016 ◽

Vol 2016 ◽

pp. 1-8 ◽

Cited By ~ 6

Author(s):

Haddad A. El Rabey ◽

Abdulrahman L. Al-Malki ◽

Khalid O. Abulnaja

Keyword(s):

Salt Stress ◽

Drought Stress ◽

Drought Tolerance ◽

Date Palm ◽

Proteome Analysis ◽

Rubisco Activase ◽

2D Electrophoresis ◽

Severe Drought ◽

Protein Abundance ◽

Low Protein

Date palm cultivars differently tolerate salinity and drought stress. This study was carried out to study the response of date palm to severe salinity and drought based on leaf proteome analysis. Eighteen-month-old date palm plants were subjected to severe salt (48 g/L NaCl) and drought (82.5 g/L PEG or no irrigation) conditions for one month. Using a protein 2D electrophoresis method, 55 protein spots were analyzed using mass spectrometry. ATP synthase CF1 alpha chains were significantly upregulated under all three stress conditions. Changes in the abundance of RubisCO activase and one of the RubisCO fragments were significant in the same spots only for salt stress and drought stress with no irrigation, and oxygen-evolving enhancer protein 2 was changed in different spots. Transketolase was significantly changed only in drought stress with PEG. The expression of salt and drought stress genes of the chosen protein spots was either overexpressed or downexpressed as revealed by the high or low protein abundance, respectively. In addition, all drought tolerance genes due to no irrigation were downregulated. In conclusion, the proteome analysis of date palm under salinity and drought conditions indicated that both salinity and drought tolerance genes were differentially expressed resulting in high or low protein abundance of the chosen protein spots as a result of exposure to drought and salinity stress condition.

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