scholarly journals The Arabidopsis SMALL AUXIN UP RNA32 Protein Regulates ABA-Mediated Responses to Drought Stress

2021 ◽  
Vol 12 ◽  
Author(s):  
Yanjun He ◽  
Yue Liu ◽  
Mengzhuo Li ◽  
Anthony Tumbeh Lamin-Samu ◽  
Dandan Yang ◽  
...  
Keyword(s):  
Drought Stress ◽  
Negative Impact ◽  
Stomatal Closure ◽  
Bimolecular Fluorescence Complementation ◽  
Limiting Factors ◽  
Ion Leakage ◽  
Drought Treatment ◽  
Aba Signal Transduction ◽  
Aba Sensitivity ◽  
Exact Function

SMALL AUXIN UP-REGULATED RNAs (SAURs) are recognized as auxin-responsive genes involved in the regulation of abiotic stress adaptive growth. Among the growth-limiting factors, water-deficit condition significantly affects plant growth and development. The putative function of SAUR family member AtSAUR32 has the potential to diminish the negative impact of drought stress, but the exact function and mode of action remain unclear in Arabidopsis. In the current study, AtSAUR32 gene was cloned and functionally analyzed. AtSAUR32 localized to the plasma membrane and nucleus was dominantly expressed in roots and highly induced by abscisic acid and drought treatment at certain time points. The stomatal closure and seed germination of saur32 were less sensitive to ABA relative to AtSAUR32-overexpressed line (OE32-5) and wild type (WT). Moreover, the saur32 mutant under drought stress showed increased ion leakage while quantum yield of photosystem II (ΦPSII) and endogenous ABA accumulation were reduced, along with the expression pattern of ABA/stress-responsive genes compared with WT and the OE32-5 transgenic line. Additionally, yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays showed that AtSAUR32 interacted with clade-A PP2C proteins (AtHAI1 and AtAIP1) to regulate ABA sensitivity in Arabidopsis. Taken together, these results indicate that AtSAUR32 plays an important role in drought stress adaptation via mediating ABA signal transduction.

scholarly journals MeSPL9 Attenuates Drought Resistance by Regulating JA Signaling and Protectant Metabolite Contents in Cassava

2021 ◽  
Author(s):  
Shuxia Li ◽  
Zhihao Cheng ◽  
Zhibo Li ◽  
Shiman Dong ◽  
Xiaoling Yu ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Resistance ◽  
Stomatal Closure ◽  
Soluble Sugars ◽  
Dominant Negative ◽  
Pcr Analysis ◽  
Drought Treatment ◽  
Cassava Leaves ◽  
C Terminus ◽  
Ja Signaling

Abstract Drought stress severely impairs crop yield and is considered a primary threat to food security worldwide. Although the SQUAMOSA promoter binding protein-like 9 (SPL9) gene participates extensively in numerous developmental processes and in plant response to abiotic stimuli, its role and regulatory pathway in cassava (Manihot esculenta) response to the drought condition remain elusive. In the current study, we show that MeSPL9 plays negative roles in drought stress resistance. MeSPL9 expression was strongly repressed by drought treatment. Overexpression of a dominant-negative form of miR156-resistant MeSPL9, rMeSPL9-SRDX, in which a 12-amino acid repressor sequence was fused to rMeSPL9 at the C terminus, conferred drought tolerance without penalizing overall growth. rMeSPL9-SRDX-overexpressing lines not only exhibited increased osmoprotectant metabolites including proline and anthocyanin, but also accumulated more endogenous jasmonic acid (JA) and soluble sugars. Transcriptomic and real-time PCR analysis suggested that differentially expressed genes were involved in sugar or JA biosynthesis, signaling, and metabolism in transgenic cassava under drought conditions. Exogenous application of JA further confirmed that JA conferred improved drought resistance and promoted stomatal closure in cassava leaves. Taken together, our findings suggest that MeSPL9 affects drought resistance by modulating protectant metabolite levels and JA signaling, which have substantial implications for engineering drought tolerant crops.

scholarly journals Physiological Responses of Diverse Tall Fescue Cultivars to Drought Stress

HortScience ◽  
1999 ◽  
Vol 34 (5) ◽  
pp. 897-901 ◽  
Author(s):  
Bingru Huang ◽  
Hongwen Gao
Keyword(s):  
Drought Stress ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Drought Resistance ◽  
Tall Fescue ◽  
Physiological Responses ◽  
Stomatal Closure ◽  
Photochemical Efficiency ◽  
Limiting Factors

Drought is among the most limiting factors for turfgrass growth. Understanding genetic variations and physiological mechanisms in turfgrass drought resistance would facilitate breeding and management programs to improve drought resistance. The experiment was designed to investigate shoot physiological responses of six tall fescue (Festuca arundinacea Schreb.) cultivars representing several generations of turfgrass improvement to drought stress. Grasses were grown in well-watered or drying (nonirrigated) soil for 35 days in the greenhouse. Net photosynthetic rate (Pn), stomatal conductance (gs), transpiration rate (Tr), relative water content (RWC), and photochemical efficiency (Fv/Fm) declined during drought progression in all cultivars, but the time and the severity of reductions varied with cultivar and physiological factors. The values of Pn, RWC, gs, and Tr decreased significantly for `Rebel Jr', `Bonsai', and `Phoenix' when soil water content declined to 20% after 9 days of treatment (DOT) and for `Houndog V', `Kentucky-31', and `Falcon II' when soil water content dropped to 10% at 15 DOT. A significant decrease in Fv/Fm was not observed in drought-stressed plants until 21 DOT for `Rebel Jr', `Bonsai', and `Phoenix' and 28 DOT for `Houndog V', `Kentucky-31', and `Falcon II'. The decline in Pn resulted mainly from internal water deficit and stomatal closure under mild drought-stress conditions. After a prolonged period of drought stress (35 DOT), `Falcon II', `Houndog V', and `Kentucky-31' maintained higher Pn than did `Rebel Jr', `Bonsai', and `Phoenix', which could be attributed to their higher Fv/Fm. This study demonstrated variation in drought resistance among tall fescue cultivars, which was related to their differential responses in photosynthetic capacity and water relations.

scholarly journals Key Proteins and Metabolic Pathways Involved in 24-Epibrasionlide Improving Drought Tolerance of Rhododendron delavayi Franch

Horticulturae ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 501
Author(s):  
Yan-Fei Cai ◽  
Lu Zhang ◽  
Lv-Chun Peng ◽  
Shi-Feng Li ◽  
Jie Song ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Metabolic Pathways ◽  
Expression Profiles ◽  
Stomatal Closure ◽  
Soluble Sugar ◽  
Ether Lipid ◽  
Photosynthetic Performance ◽  
Drought Treatment ◽  
Pre Treatment

Rhododendron delavayi Franch. is a famous ornamental plant. However, seasonal drought caused by a monsoon climate seriously limits its growth and flowering performance in urban gardens. Our previous study has found that brassinosteroids (BRs) can improve the tolerance of R. delavayi to drought stress. Here, we employed a data-independent acquisition (DIA) approach to compare the protein expression profiles under drought treatment (D) and pre-treatment with BR before drought treatment (BR). With an increase in drought stress, the net photosynthetic rate, stomatal conductance, and transpiration rate in the BR treatment showed more stable changes that were significantly higher than those in the D treatment. However, the contents of malondialdehyde, soluble sugar, soluble protein, and the activity of superoxide dismutase (SOD), peroxidase, and catalase showed opposite trends. The pre-treatment with BR alleviated the negative effect of drought stress on the photosynthetic performance of R. delavayi. A total of 3453 differentially expressed proteins (DEPs) were identified, and 683 DEPs were significantly expressed in the D and BR treatments. The DEPs uniquely expressed in the BR treatment participated in the pathways of “ribosome”, “ether lipid metabolism”, “photosynthesis”, and “oxidative phosphorylation”. The improvement effect of the BR treatment on the drought tolerance of R. delavayi was mainly attributed to improved photosynthesis by alleviating stomatal closure and oxidative stress, maintaining the integrity and stability of the ribosomal complex to mediate protein synthesis and the balance between energy metabolism and carbon metabolism. Our study presents a comprehensive understanding of the key proteins and metabolic pathways related to the response of R. delavayi to drought and will contribute to the breeding of drought-tolerant rhododendrons.

scholarly journals CmLOX10 positively regulates drought tolerance through jasmonic acid -mediated stomatal closure in oriental melon (Cucumis melo var. makuwa Makino)

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Qiaojuan Xing ◽  
Jingjing Liao ◽  
Songxiao Cao ◽  
Meng Li ◽  
Tinghui Lv ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Jasmonic Acid ◽  
Foliar Application ◽  
Stomatal Closure ◽  
Stomatal Aperture ◽  
Drought Treatment ◽  
Indirect Response ◽  
Oriental Melon ◽  
Ja Signaling

Abstract Drought stress severely impairs plant growth and production. Lipoxygenase (LOX), a master regulator for lipid peroxidation, is critical for direct or indirect response to abiotic stresses. Here, we found that drought stress induced the transcription of CmLOX10 in leaves of oriental melon seedlings. Reverse genetic approaches and physiological analyses revealed that silencing CmLOX10 increased drought susceptibility and stomatal aperture in oriental melon seedlings, and that ectopic overexpression of CmLOX10 in Arabidopsis enhanced drought tolerance and decreased the stomatal aperture. Moreover, the transcription of jasmonic acid (JA)-related genes and JA accumulation were significantly induced in CmLOX10-overexpressed Arabidopsis, which were reversely suppressed in CmLOX10-silenced seedlings during the stage of drought stress. Foliar application of JA further verified that JA enhanced drought tolerance and induced stomatal closure in leaves of melon seedlings. In addition, the feedback regulation of CmLOX10 was induced by JA signaling, and the expression level of CmMYC2 was increased by JA and drought treatment. Yeast one-hybrid analysis showed that CmMYC2 directly bound to the promoter of CmLOX10. In summary, we identified the important roles of CmLOX10 in the regulation of drought tolerance in oriental melon seedlings through JA- mediated stomatal closure and JA signaling-mediated feedback through CmMYC2.

Respon Morfologis dan Ekspresi Gen Aquaporin pada Padi IR 64 yang Mengalami Cekaman Kekeringan pada Fase Reproduktif (Morphological Responses and Aquaporin Gene Expression in Rice IR64 under Drought Stress at the Reproductive Stage)

2018 ◽  
Vol 7 (2) ◽  
Author(s):  
Made Pharmawati ◽  
Ni Nyoman Wirasiti ◽  
Luh Putu Wrasiati
Keyword(s):  
Gene Expression ◽  
Drought Stress ◽  
Real Time ◽  
Real Time Pcr ◽  
Control Plant ◽  
Reproductive Stage ◽  
Limiting Factors ◽  
Rice Grain ◽  
Aquaporin Gene ◽  
Peg Treatment

Abstrak Cekaman kekeringan merupakan faktor pembatas penting bagi pertumbuhan dan produktivitas tanaman termasuk padi.      Penelitian ini bertujuan menganalisis respon padi IR64 terhadap cekaman kekeringan dengan pemberian polietilen glikol (PEG) pada fase reproduktif.  Penelitian juga bertujuan menganalisis ekspresi gen aquaporin akibat cekaman kekeringan.  Bibit padi ditanam dalam pot dan perlakuan PEG dengan konsentrasi 108g/L (-0.25MPa) dan 178g/L (-0.52 MPa) diberikan saat munculnya panikula. Perlakuan diberikan selama 2 minggu, kemudian tanaman disiram kembali.  Ekspresi gen diamati pada akhir perlakuan dengan semi kuantitatif real time PCR.  Ekstraksi RNA menggunakan RNeasy plant mini kit, sedangkan sintesis cDNA menggunakan Transcriptor First Strand cDNA Kit.  Hasil penelitian menunjukkan bahwa jumlah malai dan berat total malai berkurang akibat cekaman kekeringan.  Persentase gabah kosong mencapai 84,6% pada perlakuan PEG-0,52 MPa, sedangkan pada perlakuan PEG -0,25 MPa persentase gabah kosong sebesar 67,8%.  Pada kontrol persentase gabah kosong adalah 10,3%.  Ekspresi gen OsPIP2;7 sedikit menurun pada perlakuan PEG -0,52 MPa.Kata kunci: ekspresi gen, IR64, kekeringan, padi, PEG  Abstract Drought stress is one of the limiting factors of plant growth and productivity including rice.  The aim of this study was to analyze responses of IR64 rice to polyethylene glycol (PEG)-induced-drought stress at the reproductive stage.  This study also aimed to analyze the expression of aquaporin under drought stress.  Rice seedlings were grown in pot system and PEG treatment at concentration of -0.25MPa (108g/L) and -0.52 MPa (178g/L) were given when the panicles arose.  Treatments were conducted for 2 weeks, after that the plants were rewatered.  Gene expression was evaluated at the end of PEG treatment using semi quantitative real time PCR. RNA was extracted using RNeasy plant mini kit, while cDNA synthesis was done using Transcriptor First Strand cDNA Kit.  The results showed that the number and weight of rice ear were less in plant treated with PEG than in control.  The percentage of empty rice grain reached 84.6% at PEG -0.52 MPa, while at PEG -0.25 MPa the percentage of empty grain was 67.8%.  In control plant, the percentage of empty grain was 10.3%.  Drought stress did not alter the expression of OsPIP2;7.  Keywords: drought, gene expression, IR64, PEG, rice

scholarly journals Flavonoids improve drought tolerance of maize seedlings by regulating the homeostasis of reactive oxygen species

2021 ◽  
Author(s):  
Baozhu Li ◽  
Ruonan Fan ◽  
Guiling Sun ◽  
Ting Sun ◽  
Yanting Fan ◽  
...  
Keyword(s):  
Free Radicals ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Infrared Imaging ◽  
Oxygen Free Radicals ◽  
Transcriptome Profiling ◽  
Far Infrared ◽  
Drought Treatment ◽  
Physiological Characterization ◽  
Oxidative Damages

Abstract Background and aims As drought threatens the yield and quality of maize (Zea mays L.), it is important to dissect the molecular basis of maize drought tolerance. Flavonoids, participate in the scavenging of oxygen free radicals and alleviate stress-induced oxidative damages. This study aims to dissect the function of flavonoids in the improvement of maize drought tolerance. Methods Using far-infrared imaging screening, we previously isolated a drought overly insensitivity (doi) mutant from an ethyl methanesulfonate (EMS)-mutagenized maize library and designated it as doi57. In this study, we performed a physiological characterization and transcriptome profiling of doi57 in comparison to corresponding wild-type B73 under drought stress. Results Under drought stress, doi57 seedlings displayed lower leaf-surface temperature (LST), faster water loss, and better performance in growth than B73. Transcriptome analysis reveals that key genes involved in flavonoid biosynthesis are enriched among differentially expressed genes in doi57. In line with these results, more flavonols and less hydrogen peroxide (H2O2) were accumulated in guard cells of doi57 than in those of B73 with the decrease of soil water content (SWC). Moreover, the capacity determined from doi57 seedling extracts to scavenge oxygen free radicals was more effective than that of B73 under the drought treatment. Additionally, doi57 seedlings had higher photosynthetic rates, stomatal conductance, transpiration rates, and water use efficiency than B73 exposed to drought stress, resulting in high biomass and greater root/shoot ratios in doi57 mutant plants. Conclusion Flavonoids may facilitate maize seedling drought tolerance by lowering drought-induced oxidative damage as well regulating stomatal movement.

scholarly journals Comparing transcriptional responses to Fusarium crown rot in wheat and barley identified an important relationship between disease resistance and drought tolerance

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Z. Y. Su ◽  
J. J. Powell ◽  
S. Gao ◽  
M. Zhou ◽  
C. Liu
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Crown Rot ◽  
Differentially Expressed ◽  
Transcriptional Responses ◽  
Drought Treatment ◽  
Crop Species ◽  
Fusarium Crown Rot ◽  
Important Relationship ◽  
The Impact

Abstract Background Fusarium crown rot (FCR) is a chronic disease in cereal production worldwide. The impact of this disease is highly environmentally dependant and significant yield losses occur mainly in drought-affected crops. Results In the study reported here, we evaluated possible relationships between genes conferring FCR resistance and drought tolerance using two approaches. The first approach studied FCR induced differentially expressed genes (DEGs) targeting two barley and one wheat loci against a panel of genes curated from the literature based on known functions in drought tolerance. Of the 149 curated genes, 61.0% were responsive to FCR infection across the three loci. The second approach was a comparison of the global DEGs induced by FCR infection with the global transcriptomic responses under drought in wheat. This analysis found that approximately 48.0% of the DEGs detected one week following drought treatment and 74.4% of the DEGs detected three weeks following drought treatment were also differentially expressed between the susceptible and resistant isolines under FCR infection at one or more timepoints. As for the results from the first approach, the vast majority of common DEGs were downregulated under drought and expressed more highly in the resistant isoline than the sensitive isoline under FCR infection. Conclusions Results from this study suggest that the resistant isoline in wheat was experiencing less drought stress, which could contribute to the stronger defence response than the sensitive isoline. However, most of the genes induced by drought stress in barley were more highly expressed in the susceptible isolines than the resistant isolines under infection, indicating that genes conferring drought tolerance and FCR resistance may interact differently between these two crop species. Nevertheless, the strong relationship between FCR resistance and drought responsiveness provides further evidence indicating the possibility to enhance FCR resistance by manipulating genes conferring drought tolerance.

scholarly journals Arabidopsis MADS-box factor AGL16 negatively regulates drought resistance via stomatal density and stomatal movement

2020 ◽  
Vol 71 (19) ◽  
pp. 6092-6106 ◽  
Author(s):  
Ping-Xia Zhao ◽  
Zi-Qing Miao ◽  
Jing Zhang ◽  
Si-Yan Chen ◽  
Qian-Qian Liu ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Resistance ◽  
Molecular Mechanisms ◽  
Stomatal Density ◽  
Stomatal Closure ◽  
Negative Regulator ◽  
Stomatal Development ◽  
Mads Box ◽  
Mobility Shift ◽  
Aba Metabolism

Abstract Drought is one of the most important environmental factors limiting plant growth and productivity. The molecular mechanisms underlying plant drought resistance are complex and not yet fully understood. Here, we show that the Arabidopsis MADS-box transcription factor AGL16 acts as a negative regulator in drought resistance by regulating stomatal density and movement. Loss-of-AGL16 mutants were more resistant to drought stress and had higher relative water content, which was attributed to lower leaf stomatal density and more sensitive stomatal closure due to higher leaf ABA levels compared with the wild type. AGL16-overexpressing lines displayed the opposite phenotypes. AGL16 is preferentially expressed in guard cells and down-regulated in response to drought stress. The expression of CYP707A3 and AAO3 in ABA metabolism and SDD1 in stomatal development was altered in agl16 and overexpression lines, making them potential targets of AGL16. Using chromatin immunoprecipitation, transient transactivation, yeast one-hybrid, and electrophoretic mobility shift assays, we demonstrated that AGL16 was able to bind the CArG motifs in the promoters of the CYP707A3, AAO3, and SDD1 and regulate their transcription, leading to altered leaf stomatal density and ABA levels. Taking our findings together, AGL16 acts as a negative regulator of drought resistance by modulating leaf stomatal density and ABA accumulation.

scholarly journals C-Repeat Binding Factor and Dehydrin Genes are Induced Co-Ordinately in Drought Tolerance Response of Wheat Cultivars

2017 ◽  
Vol 9 (2) ◽  
pp. 18 ◽  
Author(s):  
Csilla Deák ◽  
Katalin Jäger ◽  
Veronika Anna Nagy ◽  
Réka Oszlányi ◽  
Beáta Barnabás ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Mrna Level ◽  
Drought Treatment ◽  
Drought Tolerant ◽  
Aba Sensitivity ◽  
Defence Genes ◽  
Binding Factor ◽  
Tolerance Response ◽  
Pcr Method

Four bread wheat genotypes with contrasting drought stress tolerance were studied. Expression levels of dehydrin (Wdhn13) and C-repeat binding factor (Cbf14, Cbf15) genes were investigated in leaves of two drought tolerant (Plainsman V, Mv Emese) and two sensitive (GK Élet, Cappelle Desprez) cultivars by semi-quantitative RT-PCR during drought treatment at anthesis. Coordinate induction of Cbf14, Cbf15 and Wdhn13 genes occurred at a late stage of stress treatment in all cultivars except the most sensitive Cappelle Desprez, where no induction was evident. The most pronounced late induction of genes was observed in the tolerant Mv Emese genotype. Cbf14, Cbf15 and Wdhn13 showed largely parallel changes of expression in stressed adult plants. The mRNA level of the same set of genes was measured in leaves of non-stressed seedlings with qRT-PCR method. Expression level of Wdhn13 was high and low in seedlings of tolerant and sensitive cultivars, respectively. Cbf15 specific transcript was barely detectable in leaves of non-stressed seedlings. In order to shed light on any potential difference in hormone responsiveness, seedlings were subjected to ABA treatment in vitro. At low hormone concentrations (10 and 20 µM ABA) consistently weaker ABA induced root growth retardation of GK Élet was found in comparison with the other three cultivars. Results highlight pronounced and late induction of a set of defence genes and low ABA sensitivity as features appearing in drought tolerant and sensitive responses, respectively. Data is discussed in the light of multifactorial determination of the complex phenotype of drought tolerance in wheat.

scholarly journals Comparative Proteomics of Root Apex and Root Elongation Zones Provides Insights into Molecular Mechanisms for Drought Stress and Recovery Adjustment in Switchgrass

Proteomes ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 3 ◽  
Author(s):  
Zhujia Ye ◽  
Sasikiran Reddy Sangireddy ◽  
Chih-Li Yu ◽  
Dafeng Hui ◽  
Kevin Howe ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Drought Stress ◽  
Molecular Mechanisms ◽  
Root Zone ◽  
Root Apex ◽  
Root Tip ◽  
Leaf Water Content ◽  
Severe Drought ◽  
Proteomics Data ◽  
Drought Treatment

Switchgrass plants were grown in a Sandwich tube system to induce gradual drought stress by withholding watering. After 29 days, the leaf photosynthetic rate decreased significantly, compared to the control plants which were watered regularly. The drought-treated plants recovered to the same leaf water content after three days of re-watering. The root tip (1cm basal fragment, designated as RT1 hereafter) and the elongation/maturation zone (the next upper 1 cm tissue, designated as RT2 hereafter) tissues were collected at the 29th day of drought stress treatment, (named SDT for severe drought treated), after one (D1W) and three days (D3W) of re-watering. The tandem mass tags mass spectrometry-based quantitative proteomics analysis was performed to identify the proteomes, and drought-induced differentially accumulated proteins (DAPs). From RT1 tissues, 6156, 7687, and 7699 proteins were quantified, and 296, 535, and 384 DAPs were identified in the SDT, D1W, and D3W samples, respectively. From RT2 tissues, 7382, 7255, and 6883 proteins were quantified, and 393, 587, and 321 proteins DAPs were identified in the SDT, D1W, and D3W samples. Between RT1 and RT2 tissues, very few DAPs overlapped at SDT, but the number of such proteins increased during the recovery phase. A large number of hydrophilic proteins and stress-responsive proteins were induced during SDT and remained at a higher level during the recovery stages. A large number of DAPs in RT1 tissues maintained the same expression pattern throughout drought treatment and the recovery phases. The DAPs in RT1 tissues were classified in cell proliferation, mitotic cell division, and chromatin modification, and those in RT2 were placed in cell wall remodeling and cell expansion processes. This study provided information pertaining to root zone-specific proteome changes during drought and recover phases, which will allow us to select proteins (genes) as better defined targets for developing drought tolerant plants. The mass spectrometry proteomics data are available via ProteomeXchange with identifier PXD017441.

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