Expression of OsDREB2A in Transgenic Tomato Improves Drought Tolerance

Dehydration responsive element binding (DREB) are important regulatory molecules which have a crucial role in abiotic stress tolerance. The productivity of tomato, as a drought-sensitive crop, is highly restricted by drought stress. The current study aimed at introducing the OsDERB2A gene into two tomato genotypes via Agrobacterium-mediated transformation system. Cotyledonary explants were pre-cultured for two days with Agrobacterium strain LBA4404 harboring pCAMBIA1301 with OsDREB2A driven by the constitutive promoter CaMV35S for transformation. Shoots were directly regenerated on MS medium containing 1 mg l-1 zeatin and 1 mg l-1 BAP, and in presence of 30 mg l-1 hygromycin as selective agent. Only eight weeks were needed to regenerate transgenic tomato using this protocol. An OD600 of 0.4 resulted in 64.3-76.9% transformation efficiency. Stable integration and expression of the OsDREB2A gene were confirmed in transgenic tomato using PCR and RT-PCR analyses, and drought tolerance of T0 transgenic lines was confirmed by leaf disc assay in 300 mM mannitol. The superior biomass, photosynthetic pigments, free soluble sugars and proline accumulation of OsDREB2A transgenic lines over wild type in response to mannitol-stress revealed their enhanced drought tolerance and indicated that the constitutive expression of OsDREB2A might modulate the expression of other drought responsive genes.

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Genetic improvement of Chinese cabbage for salt and drought tolerance by constitutive expression of a B. napus LEA gene

Plant Science ◽

10.1016/j.plantsci.2005.05.008 ◽

2005 ◽

Vol 169 (3) ◽

pp. 553-558 ◽

Cited By ~ 83

Author(s):

Byong-Jin Park ◽

Zaochang Liu ◽

Akira Kanno ◽

Toshiaki Kameya

Keyword(s):

Drought Tolerance ◽

Chinese Cabbage ◽

Genetic Improvement ◽

Constitutive Expression ◽

Salt And Drought Tolerance ◽

Lea Gene

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Overexpression of antizyme in the hearts of transgenic mice prevents the isoprenaline-induced increase in cardiac ornithine decarboxylase activity and polyamines, but does not prevent cardiac hypertrophy

Biochemical Journal ◽

10.1042/bj3500645 ◽

2000 ◽

Vol 350 (3) ◽

pp. 645-653 ◽

Cited By ~ 11

Author(s):

Caroline A. MACKINTOSH ◽

David J. FEITH ◽

Lisa M. SHANTZ ◽

Anthony E. PEGG

Keyword(s):

Transgenic Mice ◽

Ornithine Decarboxylase ◽

Prolonged Exposure ◽

Constitutive Expression ◽

Decarboxylase Activity ◽

Cardiac Growth ◽

Polyamine Content ◽

Transgenic Lines ◽

Response To Stress ◽

Polyamine Uptake

Two lines of transgenic mice were produced with constitutive expression of antizyme-1 in the heart, driven from the cardiac α-myosin heavy chain promoter. The use of engineered antizyme cDNA in which nucleotide 205 had been deleted eliminated the need for polyamine-mediated frameshifting, normally necessary for translation of antizyme mRNA, and thus ensured the constitutive expression of antizyme. Antizyme-1 is thought to be a major factor in regulating cellular polyamine content, acting both to inhibit ornithine decarboxylase (ODC) activity and to target it for degradation, as well as preventing polyamine uptake. The two transgenic lines had substantial, but different, levels of antizyme in the heart, as detected by Western blotting and by the ability of heart extracts to inhibit exogenous purified ODC. Despite the high levels of antizyme, endogenous ODC activity was not completely abolished, with 10– 39% remaining, depending on the transgenic line. Additionally, a relatively small decrease (30–32%) in cardiac spermidine content was observed, with levels of putrescine and spermine unaffected. Interestingly, although the two lines of transgenic mice had different antizyme expression levels, they had almost identical cardiac polyamine content. When treated with a single acute dose of isoprenaline (isoproterenol), cardiac ODC activity and putrescine content were substantially increased (by 14-fold and 4.7-fold respectively) in non-transgenic littermate mice, but these increases were completely prevented in the transgenic mice from both founder lines. Prolonged exposure to isoprenaline also caused increases in cardiac ODC activity and polyamine content, as well as an increase in cardiac growth, in non-transgenic mice. Although the increases in cardiac ODC activity and polyamine content were prevented in the transgenic mice from both founder lines, the increase in cardiac growth was unaffected. These transgenic mice thus provide a valuable model system in which to study the importance of polyamine levels in cardiac growth and electrophysiology in response to stress.

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Molecular cloning, bioinformatics, and expression profiling of a dehydration-responsive element-binding-2 (DREB2) homologue fromFestuca arundinacea,FapDREB2, with high drought tolerance

The Journal of Horticultural Science and Biotechnology ◽

10.1080/14620316.2008.11512370 ◽

2008 ◽

Vol 83 (2) ◽

pp. 199-206 ◽

Cited By ~ 1

Author(s):

Zhifei Zhang ◽

Liqun Rao ◽

Zhiyang Zhang ◽

Zuoxiang Xiang ◽

Zhijian Yang ◽

...

Keyword(s):

Drought Tolerance ◽

Molecular Cloning ◽

Expression Profiling ◽

Responsive Element

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Mechanisms of Response to Salt Stress in Oleander (Nerium oleander L.)

Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca Horticulture ◽

10.15835/buasvmcn-hort:12287 ◽

2016 ◽

Vol 73 (2) ◽

pp. 249

Author(s):

Dinesh Kumar ◽

Mohamad Al Hassan ◽

Oscar Vicente ◽

Veena Agrawal ◽

Monica Boscaiu

Keyword(s):

Salt Stress ◽

Abiotic Stress Tolerance ◽

Soluble Sugar ◽

Soluble Sugars ◽

Nerium Oleander ◽

Antioxidant Systems ◽

Change Scenario ◽

Antioxidant Compounds ◽

Stress Dependent

Elucidating the mechanisms of abiotic stress tolerance in different species will help to develop more resistant plant varieties, contributing to improve agricultural production in a climate change scenario. Basic responses to salt stress, dependent on osmolyte accumulation and activation of antioxidant systems, have been studied in Nerium oleander, a xerophytic species widely used as ornamental. Salt strongly inhibited growth, but the plants survived one-month treatments with quite high NaCl concentrations, up to 800 mM, indicating the the species is relatively resistant to salt stress, in addition to drought. Levels of proline, glycine betaine and soluble sugars increased only slightly in the presence of salt; however, soluble sugar absolute contents were much higher than those of the other osmolytes, suggesting a functional role of these compounds in osmotic adjustment, and the presence of constitutive mechanisms of response to salt stress. High salinity generated oxidative stress in the plants, as shown by the increase of malondialdehyde levels. Antioxidant systems, enzymatic and non-enzymatic, are generally activated in response to salt stress; in oleander, they do not seem to include total phenolics or flavonoids, antioxidant compounds which did not accumulate significantly in salt-trated plants

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Evaluation of powdery mildew resistance in various melon (Cucumis melo L.) genotypes

Agricultural Science and Technology ◽

10.15547/10.15547/ast.2018.04.053 ◽

2018 ◽

Vol 10 (4) ◽

pp. 279-284

Author(s):

Zh. Ivanova ◽

K. Vasileva ◽

N. Velkov ◽

S. Grozeva

Keyword(s):

Powdery Mildew ◽

Genetic Resistance ◽

Leaf Disc ◽

Breeding Program ◽

Vegetable Crops ◽

Plant Materials ◽

South Central ◽

Leaf Disc Assay ◽

Disc Assay

Abstract. Powdery mildew, caused by Podosphaera xanthii and Golovinomyces cichoracearum, is an economically important disease in melon worldwide. Genetic resistance is one of the most suitable strategies to control powdery mildew. During the last few years several races of the pathogens have been reported. The need to develop resistant varieties is a challenge for each breeding program. Leaf disc assay was used in phytopathology and breeding programs as a rapid and reliable method for evaluation of disease resistance in a large number of plant materials. The purpose of this study was to establish species and races of powdery mildew in Plovdiv region, South Central Bulgaria; to develop a suitable system of pathogen isolation and cultivation; to determine the resistance levels in different melon genotypes available in Maritsa Vegetable Crops Research Institute (MVCRI) - Plovdiv collection by the leaf disc assay. Fifty-three melon genotypes, including lines, varieties, hybrids and ten differential lines were tested. The data showed that causal agent of powdery mildew was race 1 of P. xanthii in Plovdiv region. Our experimental results indicated that for the long-term storage of powdery mildew it is preferable to keep a whole plant under in vitro conditions. This allows the preservation of powdery mildew for two months before transferring on a new tissue. Thirty-four of the tested melon genotypes reacted as immune or resistant and nineteen as susceptible. Resistant melon genotypes are a suitable source in initiating a new breeding program aimed to increase resistance to powdery mildew.

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RabA2b Overexpression Alters the Plasma-Membrane Proteome and Improves Drought Tolerance in Arabidopsis

Frontiers in Plant Science ◽

10.3389/fpls.2021.738694 ◽

2021 ◽

Vol 12 ◽

Author(s):

Vivek Ambastha ◽

Ifat Matityahu ◽

Dafna Tidhar ◽

Yehoram Leshem

Keyword(s):

Plasma Membrane ◽

Transgenic Plants ◽

Drought Tolerance ◽

Small Gtpases ◽

Plant Responses ◽

Rab Proteins ◽

Strong Activity ◽

Native Promoter ◽

Transgenic Lines ◽

Drought Resistant

Rab proteins are small GTPases that are important in the regulation of vesicle trafficking. Through data mining, we identified RabA2b to be stress responsive, though little is known about the involvement of RabA in plant responses to abiotic stresses. Analysis of the RabA2b native promoter showed strong activity during osmotic stress, which required the stress hormone Abscisic acid (ABA) and was restricted to the vasculature. Sequence analysis of the promoter region identified predicted binding motifs for several ABA-responsive transcription factors. We cloned RabA2b and overexpressed it in Arabidopsis. The resulting transgenic plants were strikingly drought resistant. The reduced water loss observed in detached leaves of the transgenic plants could not be explained by stomatal aperture or density, which was similar in all the genotypes. Subcellular localization studies detected strong colocalization between RabA2b and the plasma membrane (PM) marker PIP2. Further studies of the PM showed, for the first time, a distinguished alteration in the PM proteome as a result of RabA2b overexpression. Proteomic analysis of isolated PM fractions showed enrichment of stress-coping proteins as well as cell wall/cuticle modifiers in the transgenic lines. Finally, the cuticle permeability of transgenic leaves was significantly reduced compared to the wild type, suggesting that it plays a role in its drought resistant properties. Overall, these data provide new insights into the roles and modes of action of RabA2b during water stresses, and indicate that increased RabA2b mediated PM trafficking can affect the PM proteome and increase drought tolerance.

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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 ◽

10.3390/genes12111706 ◽

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.

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