scholarly journals Overexpression of a Voltage-Dependent Anion-Selective Channel (VDAC) Protein-Encoding Gene, MsVDAC, from Medicago sativa Confers Cold and Drought Tolerance to Transgenic Tobacco

Genes ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1706
Author(s):  
Mei Yang ◽  
Xinhang Duan ◽  
Zhaoyu Wang ◽  
Hang Yin ◽  
Junrui Zang ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Cold Stress ◽  
Medicago Sativa ◽  
Transgenic Tobacco ◽  
Soluble Sugars ◽  
Ros Scavenging ◽  
Osmotic Homeostasis ◽  
Voltage Dependent ◽  
Stress Responsive Genes

Voltage-dependent anion channels (VDACs) are highly conserved proteins that are involved in the translocation of tRNA and play a key role in modulating plant senescence and multiple pathways. However, the functions of VDACs in plants are still poorly understood. Here, a novel VDAC gene was isolated and identified from alfalfa (Medicago sativa L.). MsVDAC localized to the mitochondria, and its expression was highest in alfalfa roots and was induced in response to cold, drought and salt treatment. Overexpression of MsVDAC in tobacco significantly increased MDA, GSH, soluble sugars, soluble protein and proline contents under cold and drought stress. However, the activities of SOD and POD decreased in transgenic tobacco under cold stress, while the O2− content increased. Stress-responsive genes including LTP1, ERD10B and Hxk3 were upregulated in the transgenic plants under cold and drought stress. However, GAPC, CBL1, BI-1, Cu/ZnSOD and MnSOD were upregulated only in the transgenic tobacco plants under cold stress, and GAPC, CBL1, and BI-1 were downregulated under drought stress. These results suggest that MsVDAC provides cold tolerance by regulating ROS scavenging, osmotic homeostasis and stress-responsive gene expression in plants, but the improved drought tolerance via MsVDAC may be mainly due to osmotic homeostasis and stress-responsive genes.

scholarly journals Kandelia candel Thioredoxin f Confers Osmotic Stress Tolerance in Transgenic Tobacco

2020 ◽  
Vol 21 (9) ◽  
pp. 3335 ◽  
Author(s):  
Xiaoshu Jing ◽  
Jun Yao ◽  
Xujun Ma ◽  
Yanli Zhang ◽  
Yuanling Sun ◽  
...  
Keyword(s):  
Drought Stress ◽  
Transgenic Plants ◽  
Drought Tolerance ◽  
Osmotic Stress ◽  
Transgenic Tobacco ◽  
Stomatal Closure ◽  
H2o2 Production ◽  
Kandelia Candel ◽  
Ros Scavenging ◽  
Thioredoxin F

Water deficit caused by osmotic stress and drought limits crop yield and tree growth worldwide. Screening and identifying candidate genes from stress-resistant species are a genetic engineering strategy to increase drought resistance. In this study, an increased concentration of mannitol resulted in elevated expression of thioredoxin f (KcTrxf) in the nonsecretor mangrove species Kandelia candel. By means of amino acid sequence and phylogenetic analysis, the mangrove Trx was classified as an f-type thioredoxin. Subcellular localization showed that KcTrxf localizes to chloroplasts. Enzymatic activity characterization revealed that KcTrxf recombinant protein possesses the disulfide reductase function. KcTrxf overexpression contributes to osmotic and drought tolerance in tobacco in terms of fresh weight, root length, malondialdehyde (MDA) content, and hydrogen peroxide (H2O2) production. KcTrxf was shown to reduce the stomatal aperture by enhancing K+ efflux in guard cells, which increased the water-retaining capacity in leaves under drought conditions. Notably, the abscisic acid (ABA) sensitivity was increased in KcTrxf-transgenic tobacco, which benefits plants exposed to drought by reducing water loss by promoting stomatal closure. KcTrxf-transgenic plants limited drought-induced H2O2 in leaves, which could reduce lipid peroxidation and retain the membrane integrity. Additionally, glutathione (GSH) contributing to reactive oxygen species (ROS) scavenging and transgenic plants are more efficient at regenerating GSH from oxidized glutathione (GSSG) under conditions of drought stress. Notably, KcTrxf-transgenic plants had increased glucose and fructose contents under drought stress conditions, presumably resulting from KcTrxf-promoted starch degradation under water stress. We conclude that KcTrxf contributes to drought tolerance by increasing the water status, by enhancing osmotic adjustment, and by maintaining ROS homeostasis in transgene plants.

Water loss prevention plays a greater role than ROS scavenging in dehydration tolerance of Kalanchoe tubiflora epiphyllous buds

2015 ◽  
Vol 62 (3) ◽  
pp. 153-159 ◽  
Author(s):  
Yin Ling Luo ◽  
Zhi Long Su ◽  
Xian Liang Cui ◽  
Qin Ying Lan
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Water Loss ◽  
Seedling Survival ◽  
Soluble Sugars ◽  
Dry Weight ◽  
Ros Scavenging ◽  
Superoxide Anion Production ◽  
Kalanchoe Tubiflora ◽  
Epiphyllous Buds

Different plants and plant organs have various strategies to cope with drought stress.Kalanchoe tubifloraplants have a strong ability to prevent water loss and to scavenge reactive oxygen species. The epiphyllous bud of the plant serves as a reproduction unit and is able to generate plantlets even under conditions of extreme drought. The aim of this project was to study the antioxidant-stress response and osmoregulation ofK. tubifloraepiphyllous buds to dehydration and to compare the drought-tolerance mechanisms of the plant body and the epiphyllous buds. With the progression of bud dehydration, relative water content, seedling survival rate and dry weight per seedling decreased, and electrolyte leakage, hydrogen peroxide and malondialdehyde content and superoxide anion production rate increased. The activities of the antioxidant enzymes superoxide dismutase, catalase, ascorbate peroxidase, dehydroascorbate reductase and glutathione reductase decreased under dehydration. The content of proline, soluble sugars and soluble protein increased in dehydrated buds proportionally with the extent of water loss. These data indicate that the drought-tolerance mechanism of theK. tubiflorabud was different from that of its mother plant. The buds invest more energy to prevent water loss during drought stress, and their antioxidant defense weakens.

scholarly journals Overexpression of the pitaya phosphoethanolamine N-methyltransferase gene (HpPEAMT) enhanced simulated drought stress in tobacco

2021 ◽  
Author(s):  
Ai-Hua Wang ◽  
Lan Yang ◽  
Xin-Zhuan Yao ◽  
Xiao-Peng Wen
Keyword(s):  
Drought Stress ◽  
Stress Response ◽  
Transgenic Plants ◽  
Drought Tolerance ◽  
Transgenic Tobacco ◽  
Sequence Similarity ◽  
Amino Acid Sequence Similarity ◽  
Transgenic Tobacco Plants ◽  
Wild Type ◽  
Tobacco Plants

AbstractPhosphoethanolamine N-methyltransferase (PEAMTase) catalyzes the methylation of phosphoethanolamine to produce phosphocholine and plays an important role in the abiotic stress response. Although the PEAMT genes has been isolated from many species other than pitaya, its role in the drought stress response has not yet been fully elucidated. In the present study, we isolated a 1485 bp cDNA fragment of HpPEAMT from pitaya (Hylocereus polyrhizus). Phylogenetic analysis showed that, during its evolution, HpPEAMT has shown a high degree of amino acid sequence similarity with the orthologous genes in Chenopodiaceae species. To further investigate the function of HpPEAMT, we generated transgenic tobacco plants overexpressing HpPEAMT, and the transgenic plants accumulated significantly more glycine betaine (GB) than did the wild type (WT). Drought tolerance trials indicated that, compared with those of the wild-type (WT) plants, the roots of the transgenic plants showed higher drought tolerance ability and exhibited improved drought tolerance. Further analysis revealed that overexpression of HpPEAM in Nicotiana tabacum resulted in upregulation of transcript levels of GB biosynthesis-related genes (NiBADH, NiCMO and NiSDC) in the leaves. Furthermore, compared with the wild-type plants, the transgenic tobacco plants displayed a significantly lower malondialdehyde (MDA) accumulation and higher activities of the superoxide dismutase (SOD) and peroxidase (POD) antioxidant enzymes under drought stress. Taken together, our results suggested that HpPEAMT enhanced the drought tolerance of transgenic tobacco.

scholarly journals A Novel WRKY Transcription Factor from Ipomoea trifida, ItfWRKY70, Confers Drought Tolerance in Sweet Potato

2022 ◽  
Vol 23 (2) ◽  
pp. 686
Author(s):  
Sifan Sun ◽  
Xu Li ◽  
Shaopei Gao ◽  
Nan Nie ◽  
Huan Zhang ◽  
...  
Keyword(s):  
Drought Stress ◽  
Transgenic Plants ◽  
Drought Tolerance ◽  
Sweet Potato ◽  
Stress Responses ◽  
Leaf Tissue ◽  
Stomatal Aperture ◽  
Ros Scavenging ◽  
Ipomoea Trifida ◽  
Positive Role

WRKY transcription factors are one of the important families in plants, and have important roles in plant growth, abiotic stress responses, and defense regulation. In this study, we isolated a WRKY gene, ItfWRKY70, from the wild relative of sweet potato Ipomoea trifida (H.B.K.) G. Don. This gene was highly expressed in leaf tissue and strongly induced by 20% PEG6000 and 100 μM abscisic acid (ABA). Subcellar localization analyses indicated that ItfWRKY70 was localized in the nucleus. Overexpression of ItfWRKY70 significantly increased drought tolerance in transgenic sweet potato plants. The content of ABA and proline, and the activity of SOD and POD were significantly increased, whereas the content of malondialdehyde (MDA) and H2O2 were decreased in transgenic plants under drought stress. Overexpression of ItfWRKY70 up-regulated the genes involved in ABA biosynthesis, stress-response, ROS-scavenging system, and stomatal aperture in transgenic plants under drought stress. Taken together, these results demonstrated that ItfWRKY70 plays a positive role in drought tolerance by accumulating the content of ABA, regulating stomatal aperture and activating the ROS scavenging system in sweet potato.

scholarly journals CsCYT75B1, a Citrus CYTOCHROME P450 Gene, Is Involved in Accumulation of Antioxidant Flavonoids and Induces Drought Tolerance in Transgenic Arabidopsis

Antioxidants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 161 ◽  
Author(s):  
Muhammad Junaid Rao ◽  
Yuantao Xu ◽  
Xiaomei Tang ◽  
Yue Huang ◽  
Jihong Liu ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Transgenic Arabidopsis ◽  
Wild Type ◽  
Ros Scavenging ◽  
Cytochrome P450 Gene ◽  
P450 Gene ◽  
Large Gene ◽  
Transgenic Lines

CYTOCHROME P450s genes are a large gene family in the plant kingdom. Our earlier transcriptome data revealed that a CYTOCHROME P450 gene of Citrus sinensis (CsCYT75B1) was associated with flavonoid metabolism and was highly induced after drought stress. Here, we characterized the function of CsCYT75B1 in drought tolerance by overexpressing it in Arabidopsis thaliana. Our results demonstrated that the overexpression of the CsCYT75B1 gene significantly enhanced the total flavonoid contents with increased antioxidant activity in transgenic Arabidopsis. The gene expression results showed that several genes that are responsible for the biosynthesis of antioxidant flavonoids were induced by 2–12 fold in transgenic Arabidopsis lines. After 14 days of drought stress, all transgenic lines displayed an enhanced tolerance to drought stress along with accumulating antioxidant flavonoids with lower superoxide radicals and reactive oxygen species (ROS) than wild type plants. In addition, drought-stressed transgenic lines possessed higher antioxidant enzymatic activities than wild type transgenic lines. Moreover, the stressed transgenic lines had significantly lower levels of electrolytic leakage than wild type transgenic lines. These results demonstrate that the CsCYT75B1 gene of sweet orange functions in the metabolism of antioxidant flavonoid and contributes to drought tolerance by elevating ROS scavenging activities.

scholarly journals OsACA6, a P-type IIB Ca2+ATPase promotes salinity and drought stress tolerance in tobacco by ROS scavenging and enhancing the expression of stress-responsive genes

2013 ◽  
Vol 76 (6) ◽  
pp. 997-1015 ◽  
Author(s):  
Kazi M. K. Huda ◽  
M. Sufara Akhter Banu ◽  
Bharti Garg ◽  
Suresh Tula ◽  
Renu Tuteja ◽  
...  
Keyword(s):  
Drought Stress ◽  
Stress Tolerance ◽  
Ros Scavenging ◽  
Drought Stress Tolerance ◽  
Stress Responsive Genes ◽  
P Type

scholarly journals Physiological and Differential Proteomic Analyses of Imitation Drought Stress Response in Sorghum bicolor Root at the Seedling Stage

2020 ◽  
Vol 21 (23) ◽  
pp. 9174
Author(s):  
Hongbing Li ◽  
Yulin Li ◽  
Qingbo Ke ◽  
Sang-Soo Kwak ◽  
Suiqi Zhang ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Sorghum Bicolor ◽  
Stress Responses ◽  
Expression Patterns ◽  
Physiological Mechanism ◽  
Seedling Stage ◽  
Ros Scavenging ◽  
Root Response

Drought is one of the most important constraints on the growth and productivity of many crops, including sorghum. However, as a primary sensing organ, the plant root response to drought has not been well documented at the proteomic level. In the present study, we compared physiological alteration and differential accumulation of proteins in the roots of sorghum (Sorghum bicolor) inbred line BT×623 response to Polyethylene Glycol (PEG)-induced drought stress at the seedling stage. Drought stress (up to 24 h after PEG treatment) resulted in increased accumulation of reactive oxygen species (ROS) and subsequent lipid peroxidation. The proline content was increased in drought-stressed plants. The physiological mechanism of sorghum root response to drought was attributed to the elimination of harmful free radicals and to the alleviation of oxidative stress via the synergistic action of antioxidant enzymes, such as superoxide dismutase, peroxidase, and polyphenol oxidase. The high-resolution proteome map demonstrated significant variations in about 65 protein spots detected on Coomassie Brilliant Blue-stained 2-DE gels. Of these, 52 protein spots were identified by matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI-TOF-TOF MS) representing 49 unique proteins; the levels of 43 protein spots were increased, and 22 were decreased under drought condition. The proteins identified in this study are involved in a variety of cellular functions, including carbohydrate and energy metabolism, antioxidant and defense response, protein synthesis/processing/degradation, transcriptional regulation, amino acid biosynthesis, and nitrogen metabolism, which contribute jointly to the molecular mechanism of outstanding drought tolerance in sorghum plants. Analysis of protein expression patterns and physiological analysis revealed that proteins associated with changes in energy usage; osmotic adjustment; ROS scavenging; and protein synthesis, processing, and proteolysis play important roles in maintaining root growth under drought stress. This study provides new insight for better understanding of the molecular basis of drought stress responses, aiming to improve plant drought tolerance for enhanced yield.

scholarly journals Antioxidant Enzymatic Activity and Osmotic Adjustment as Components of the Drought Tolerance Mechanism in Carex duriuscula

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 436
Author(s):  
Peichen Hou ◽  
Feifei Wang ◽  
Bin Luo ◽  
Aixue Li ◽  
Cheng Wang ◽  
...  
Keyword(s):  
Drought Stress ◽  
Osmotic Adjustment ◽  
Soluble Sugars ◽  
Soil Drought ◽  
Arid Environments ◽  
Ros Scavenging ◽  
Efficient Operation ◽  
Ambient Temperatures ◽  
Relative Contribution ◽  
Leaves And Roots

Drought stress is a major environmental constraint for plant growth. Climate-change-driven increases in ambient temperatures resulted in reduced or unevenly distributed rainfalls, leading to increased soil drought. Carex duriuscula C. A. Mey is a typical drought-tolerant sedge, but few reports have examined the mechanisms conferring its tolerant traits. In the present study, the drought responses of C. duriuscula were assessed by quantifying activity of antioxidant enzymes in its leaf and root tissues and evaluating the relative contribution of organic and inorganic osmolyte in plant osmotic adjustment, linking it with the patterns of the ion acquisition by roots. Two levels of stress—mild (MD) and severe (SD) drought treatments—were used, followed by re-watering. Drought stress caused reduction in a relative water content and chlorophyll content of leaves; this was accompanied by an increase in the hydrogen peroxide (H2O2) and superoxide (O2−) contents in leaves and roots. Under MD stress, the activities of catalase (CAT), peroxidase (POD), and glutathione peroxidase (GPX) increased in leaves, whereas, in roots, only CAT and POD activities increased. SD stress led to an increase in the activities of CAT, POD, superoxide dismutase (SOD), and GPX in both tissues. The levels of proline, soluble sugars, and soluble proteins in the leaves also increased. Under both MD and SD stress conditions, C. duriuscula increased K+, Na+, and Cl− uptake by plant roots, which resulted in an increased K+, Na+, and Cl− concentrations in leaves and roots. This reliance on inorganic osmolytes enables a cost-efficient osmotic adjustment in C. duriuscula. Overall, this study revealed that C. duriuscula was able to survive arid environments due to an efficient operation of its ROS-scavenging systems and osmotic adjustment mechanisms.

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