Constitutive Overexpressing At.TC Improves Drought-mediated Oxidative Tolerance in Transgenic Brassica Napus L.

Abstract Background: Environmental stresses are the most important factors limiting crops production in worldwide. Tocopherol, belonging to family of vitamin E compounds, is an amphipathic antioxidants involved in oxidative responses. In the current study, we generated transgenic canola plants overexpressing Arabidopsis VTE1 gene (At.TC) through Agrobacterium tumefaciens system. Methods and results: The putative transgenic plants were successfully regenerated and acclimated in greenhouse conditions. The transcriptional activity of the At.TC gene was evaluated by RT-PCR. In addition, the relative gene expression analysis by qRT-PCR confirmed an increased expression pattern of the transformed gene in canola transgenic lines, with the highest level in R. Line1. Given the results, the transgenic plants, particularly H. Line1 and R. Line2 showed a lower lipid peroxidation compared to WTs under FC 30%. Moreover, two ROS scavenging enzymes including CAT and PPO were up-regulated in transgenic lines; however, no significant pattern was observed for Ascorbate Peroxidase. Also, the amount of leaf tocopherol was significantly more in all T1 lines under drought stress (FC 30%). Conclusion: Taken together, here we successfully developed transgenic lines overexpressing At.TC gene constituently throughout the plant. The results confirmed that the generated transgenic plants are resistant to drought stress, thereby paving the way toward introducing canola plants to deal with the climate change and water shortage.

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

International Journal of Molecular Sciences ◽

10.3390/ijms23020686 ◽

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.

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

Antioxidants ◽

10.3390/antiox9020161 ◽

2020 ◽

Vol 9 (2) ◽

pp. 161 ◽

Cited By ~ 2

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.

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Kandelia candel Thioredoxin f Confers Osmotic Stress Tolerance in Transgenic Tobacco

International Journal of Molecular Sciences ◽

10.3390/ijms21093335 ◽

2020 ◽

Vol 21 (9) ◽

pp. 3335 ◽

Cited By ~ 1

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.

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Overexpression of the GmDREB2 gene increases proline accumulation and tolerance to drought stress in soybean plants

Australian Journal of Crop Science ◽

10.21475/ajcs.20.14.03.p2173 ◽

2020 ◽

pp. 495-503

Author(s):

Thi Thanh Nhan Pham ◽

Huu Quan Nguyen ◽

Thi Ngoc Lan Nguyen ◽

Xuan Tan Dao ◽

Danh Thuong Sy ◽

...

Keyword(s):

Glycine Max ◽

Drought Stress ◽

Transgenic Plants ◽

Proline Accumulation ◽

Stress Conditions ◽

Transgenic Soybean ◽

Transcription Level ◽

Drought Tolerant ◽

Transgenic Lines ◽

Soybean Plants

The dehydration responsive element binding (DREB) is a plant protein subfamily expressed when soybean plants face abiotic stresses. These DREB proteins are also considered to activate the transcription of drought-resistant genes. In this study, we present the determined results of relationships between overexpression of Glycine max DREB2 (GmDREB2) with the transcription level of Glycine max pyrroline-5-carboxylate synthetase (GmP5CS) gene, proline accumulation and drought tolerant ability transgenic soybean plants as the basis for selection of transgenic lines with high drought tolerance. GmDREB2 was inserted into a plant transgenic vector and the 35S-GmDREB2-cmyc construct was transferred into the soybean plants by Agrobacterium-mediated transformation. Recombinant GmDREB2 protein with a molecular weight of approximately 20 kDa was expressed in four transgenic soybean lines in the T1 generation. The GmP5CS gene was shown to have significantly (P<0.05) increased expression in the T2 transgenic soybean lines and higher than compared to non-transgenic plants with considering both in well watered condition and stressed conditions were from 1.06 to 1.31-fold and 1.37 to 1.95-fold, respectively. The proline content of four transgenic soybean lines increased 155.81% to 187.42 % after five days in drought-stress conditions and increased from 180.52 % to 233.74 % after nine days under drought-stress conditions (P<0.05). Therefore, the overexpression of GmDREB2 resulted in increasing transcription level of P5CS gene, proline accumulation and drought-stress tolerance of the transgenic soybean plants. The GmDREB2 transformation into soybean plants was confirmed by the results of genetically modified lines in the T2 generation (T2-1, T2-6, T2-7, and T2-8) with higher drought tolerant ability than those of non-transgenic plants.

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Cloning of TaPRP from Wheat and Its Cold Tolerance Analysis in Transgenic Tobacco

Journal of Agricultural Science ◽

10.5539/jas.v8n5p61 ◽

2016 ◽

Vol 8 (5) ◽

pp. 61

Author(s):

Zhang Baolei ◽

Li Da ◽

Zhang Weidong ◽

Liu Dasheng ◽

Gao Qingrong ◽

...

Keyword(s):

Transgenic Plants ◽

Cold Tolerance ◽

Transgenic Tobacco ◽

Tolerance Analysis ◽

Treatment Temperature ◽

Nucleotide Sequence Analysis ◽

Amino Acid Residues ◽

Rt Pcr ◽

Sequence Homologies ◽

Transgenic Lines

TaPRP, a proline rich protein (PRP) cDNA, was cloned by RT-PCR from winter wheat. Nucleotide sequence analysis showed TaPRP is composed of 1137 bp (378 amino acid residues with a Mr of 42.19 kD). TaPRP shows 92.6%, 89.3%, 73.0%, and 73.3% sequence homologies with PRP genes from wheat, sorghum, rice, and maize, respectively. The deduced protein includes 170 prolines, presenting a normal PRP primary structure. Expression vector pBI-TaPRP was constructed, in which TaPRP was driven by CaMV35S promoter and stopped by NospolyA. Tobaccos were transformed by Agrobacterium containing the constructed vectors. Three transgenic lines were confirmed by PCR detection and Southern blot. Under the same low temperature stress conditions, transgenic plants had lower conductivity rate compared with the non-transgenic plants, suggesting that cold tolerance in transgenic tobacco plants was improved. However, the different transgenic plants showed significant differences in cold resistant, and there also existed significant interactions between plant and treatment temperature. TaPRP might have an important role in wheat in cold adaptation process.

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Regeneration of vgb-transgenic poplar (Populus alba×P. glandulosa) and the primary observation of growth

Chinese Journal of Agricultural Biotechnology ◽

10.1079/cjb200584 ◽

2006 ◽

Vol 3 (1) ◽

pp. 59-64 ◽

Cited By ~ 2

Author(s):

Zhang Bing-Yu ◽

Su Xiao-Hua ◽

Li Yi-Liang ◽

Huang Qin-Jun ◽

Zhang Xiang-Hua ◽

...

Keyword(s):

Transgenic Plants ◽

Blot Hybridization ◽

Pcr Amplification ◽

First Year ◽

Populus Alba ◽

Rt Pcr ◽

Dot Blot ◽

Transgenic Lines ◽

Polymerase Chain ◽

Morphological Differences

AbstractIncreasing the growth rate is especially important for low-quality wood applications, so this has become an important goal in poplar breeding. The present study describes the transfer of Vitreoscilla haemoglobin (VHb) gene (vgb) driven by constitutive promoters, by Agrobacterium tumefaciens into poplar (Populus alba×P. glandulosa). From about 450 leaf discs used for transformation, 60 Kan-resistant plants were obtained, and 52 proved to be true transgenic plants. The transgenic nature of these plants was confirmed by polymerase chain reaction (PCR) amplification and Southern dot blot hybridization. The expression of vgb gene in transgenic plants was confirmed by reverse transcriptase-PCR (RT-PCR). The performance of the transgenic lines was evaluated during the first year of growth in a greenhouse. These plants showed no significant stable morphological differences from the untransformed plants. Among them, three vgb-transgenic lines exhibited noticeably higher growth rates in terms of height and diameter.

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Drought stress - related functional characterization of transcription factor GmNAC085 in soybean

Vietnam Journal of Biotechnology ◽

10.15625/1811-4989/16/4/13062 ◽

2020 ◽

Vol 16 (4) ◽

pp. 641-648

Author(s):

Tran Thi Khanh Hoa ◽

Huynh Ngoc Tuyet ◽

Nguyen Phuong Thao ◽

Hoang Thi Lan Xuan

Keyword(s):

Transcription Factor ◽

Drought Stress ◽

Shoot Growth ◽

Functional Characterization ◽

Water Shortage ◽

Plant Tolerance ◽

Wild Type ◽

Peroxidase Enzyme ◽

Scavenging Enzymes

Studies on soybean GmNAC085 transcription factor revealed that the gene expression in plants was induced by water shortage treatments and its overexpression in the model plant Arabidopsis displayed improved plant tolerance characteristics towards drought stress. In this study, we continued analyzing the biological functions of GmNAC085 using transgenic soybean system overexpressing GmNAC085 gene, by targeting at a number of plant physiological features and biochemical activities in response to limited water growing condition. Compared to the wild-type, the transgenic line demonstrated that it possessed stress tolerance characters, including enhanced elongation of taproot, minimized reduction of shoot growth, lower intracellular H2O2 content and stronger peroxidase enzyme activity under drought condition. The results of this study therefore suggest the transgenic plants had better drought tolerance and the GmNAC085 plays important role in aiding plants to cope with water deficit condition, probably via regulating the growth of roots and shoots, and activities of reactive-oxygen-species- scavenging enzymes.

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CaLEA 73 gene from Capsicum annuum L. enhances drought and osmotic tolerance modulating transpiration rate in transgenic Arabidopsis thaliana

Canadian Journal of Plant Science ◽

10.4141/cjps-2014-281 ◽

2015 ◽

Vol 95 (2) ◽

pp. 227-235 ◽

Cited By ~ 4

Author(s):

Gerardo Acosta-García ◽

Angela M. Chapa-Oliver ◽

Jesus R. Millán-Almaraz ◽

Ramón G. Guevara-González ◽

Elvira Cortez-Baheza ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Salt Stress ◽

Drought Stress ◽

Transgenic Plants ◽

Capsicum Annuum ◽

Transpiration Rate ◽

Transgenic Arabidopsis ◽

Transgenic Arabidopsis Thaliana ◽

Osmotic Tolerance ◽

Transgenic Lines

Acosta-García, G., Chapa-Oliver, A. M., Millán-Almaraz, J. R., Guevara-González, R. G., Cortez-Baheza, E., Rangel-Cano, R. M., Ramírez-Pimentel, J. G., Cruz-Hernandez, A., Gueara-Olvera, L., Aguilera-Bibian, J. E., Hernández-Salazar, M. and Torres-Pacheco, I. 2015. CaLEA 73 gene from Capsicum annuum L. enhances drought and osmotic tolerance modulating transpiration rate in transgenic Arabidopsis thaliana. Can. J. Plant Sci. 95: 227–235. Late embryogenesis abundant (LEA) proteins are an important group of proteins related to the protection of several kinds of abiotic stresses in plants. A LEA gene was cloned from Capsicum annuum seeds and named CaLEA73. This gene was expressed in C. annuum plants during several phenological stages as well as in cold stress and exogen ABA applications. The CaLEA73 gene was ectopically expressed in transgenic Arabidopsis thaliana plants in order to analyse its role under drought and salt stress. Our results displayed an increase in tolerance to drought and osmotic, but not under salt stress in the transgenic lines evaluated. Interestingly, proline levels in transgenic lines were not higher than azygous control plants, when the drought stress was evaluated. Transpiration levels in transgenic plants were lower than control, suggesting an improvement in water efficiency use in CaLEA73 transgenic lines. The stomatal density and index were significantly minor in transgenic plants in comparison to azygous control, likely indicating a reason of the minor transpiration in transgenic plants. Our results are discussed in the context of drought stress physiology aspects for crop improvement.

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BrPARP1, a Poly (ADP-Ribose) Polymerase Gene, Is Involved in Root Development in Brassica rapa under Drought Stress

Horticulturae ◽

10.3390/horticulturae8010078 ◽

2022 ◽

Vol 8 (1) ◽

pp. 78

Author(s):

Gangqiang Cao ◽

Wenjing Jiang ◽

Gongyao Shi ◽

Zhaoran Tian ◽

Jingjing Shang ◽

...

Keyword(s):

Drought Stress ◽

Root Growth ◽

Underlying Mechanism ◽

Ros Scavenging ◽

Drought Treatment ◽

Adverse Conditions ◽

Copy Numbers ◽

Transgenic Lines ◽

Stress Related Genes ◽

Genome Triplication

PARP proteins are highly conserved homologs among the eukaryotic poly (ADP-ribose) polymerases. After activation, ADP-ribose polymers are synthesized on a series of ribozymes that use NAD+ as a substrate. PARPs participate in the regulation of various important biological processes, such as plant growth, development, and stress response. In this study, we characterized the homologue of PARP1 in B. rapa using RNA interference (RNAi) to reveal the underlying mechanism responding to drought stress. Bioinformatics and expression pattern analyses demonstrated that two copy numbers of PARP1 genes (BrPARP1.A03 and BrPARP1.A05) in B. rapa following a whole-genome triplication (WGT) event were retained compared with Arabidopsis, but only BrPARP1.A03 was predominantly transcribed in plant roots. Silencing of BrPARP1 could markedly promote root growth and development, probably via regulating cell division, and the transgenic Brassica lines showed more tolerance under drought treatment, accompanied with substantial alterations including accumulated proline contents, significantly reduced malondialdehyde, and increased antioxidative enzyme activity. In addition, the findings showed that the expression of stress-responsive genes, as well as reactive oxygen species (ROS)-scavenging related genes, was largely reinforced in the transgenic lines under drought stress. In general, these results indicated that BrPARP1 likely responds to drought stress by regulating root growth and the expression of stress-related genes to cope with adverse conditions in B. rapa.

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Overexpression of Orange Gene (OsOr-R115H) Enhances Heat Tolerance and Defense-Related Gene Expression in Rice (Oryza sativa L.)

Genes ◽

10.3390/genes12121891 ◽

2021 ◽

Vol 12 (12) ◽

pp. 1891

Author(s):

Yu Jin Jung ◽

Ji Yun Go ◽

Hyo Ju Lee ◽

Jung Soon Park ◽

Jin Young Kim ◽

...

Keyword(s):

Heat Stress ◽

Oryza Sativa L ◽

Carotenoid Biosynthesis ◽

Stress Conditions ◽

Ros Scavenging ◽

Chlorophyll Contents ◽

Defense Related Gene ◽

Transgenic Lines ◽

Or Gene ◽

Scavenging Enzymes

In plants, the orange (Or) gene plays roles in regulating carotenoid biosynthesis and responses to environmental stress. The present study investigated whether the expression of rice Or (OsOr) gene could enhance rice tolerance to heat stress conditions. The OsOr gene was cloned and constructed with OsOr or OsOr-R115H (leading to Arg to His substitution at position 115 on the OsOr protein), and transformed into rice plants. The chlorophyll contents and proline contents of transgenic lines were significantly higher than those of non-transgenic (NT) plants under heat stress conditions. However, we found that the levels of electrolyte leakage and malondialdehyde in transgenic lines were significantly reduced compared to NT plants under heat stress conditions. In addition, the levels of expression of four genes related to reactive oxygen species (ROS) scavenging enzymes (OsAPX2, OsCATA, OsCATB, OsSOD-Cu/Zn) and five genes (OsLEA3, OsDREB2A, OsDREB1A, OsP5CS, SNAC1) responded to abiotic stress was showed significantly higher in the transgenic lines than NT plants under heat stress conditions. Therefore, OsOr-R115H could be exploited as a promising strategy for developing new rice cultivars with improved heat stress tolerance.

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