An Arabidopsis Mitochondrial Uncoupling Protein Confers Tolerance to Drought and Salt Stress in Transgenic Tobacco Plants

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effects of soil and foliar application of soluble silicon on mineral nutrition, gas exchange, and growth of potato plants

Silicon can alleviate biotic and abiotic stresses in several crops, and it has beneficial effects on plants under nonstressed conditions. However, there is still doubt about foliar-applied Si efficiency and Si effects on mineral nutrition, physiological processes, and growth of potato (Solanum tuberosum L.) plants under wellwatered conditions. The objective of this study was to evaluate the effect of soil and foliar application of soluble Si on Si accumulation, nutrients, and pigments concentration as well as gas exchange and growth of potato plants. The experiment was conducted under greenhouse conditions in pots containing 35 dm3 of a Typic Acrortox soil. The treatments consisted of a control (no Si application), soil application of soluble Si (50 mg dm-3 Si), and foliar application of soluble Si (three sprays of 1.425 mM Si water solution, prepared with a soluble concentrate stabilized silicic acid), with eight replications. Both soil and foliar application of Si resulted in higher Si accumulation in the whole plant. Foliar application of Si resulted in the greatest Si concentration in leaves, and soil application increased Si concentration in leaves, stems, and roots. Silicon application, regardless of the application method, increased leaf area, specific leaf area, and pigment concentration (chlorophyll a and carotenoids) as well as photosynthesis and transpiration rates of wellwatered potato plants. However, only soil application increased P concentration in leaves and dry weight of leaves and stems. © Crop Science Society of America.

Copper oxychloride fungicide and its effect on growth and oxidative stress of potato plants

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evaluation of Fe uptake and translocation in transgenic and non-transgenic soybean plants using enriched stable Fe-57 as a tracer

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Foliar or soil applications of silicon alleviate water-deficit stress of potato plants

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Second generation European corn borer injury and Irish potato physiology, yield, and quality

European corn borer (ECB) [Ostrinia nubilalis (Hubner)] (Lepidoptera: Crambidae) is known to infest Irish potato (Solanum tuberosum L.) but only causes economic damage during the first generation in East Coast potato producing areas. However, in Nebraska, second generation ECB infest potato plants during the bulking period and may reduce yield and/or potato quality. Experiments were conducted in 2001, 2002, and 2003 to examine physiological and yield effects of second generation ECB injury to potato in Nebraska. Pike, Atlantic, and three Frito Lay proprietary varieties (FL1867, FL1879, and FL1833) were used. Experimental plots were infested with four ECB egg masses per plant to simulate ECB infestation by second-generation larvae; controls received no egg masses. Photosynthetic rates, tuber weights, tuber size grades, solids, and fry quality were measured. Potato plants with ECB infestation had significantly reduced photosynthetic rates on ECB-infested stems and on uninfested stems on the same plant when larvae were in the fifth instar. When insects were in the fourth instar, photosynthetic rates were reduced only on ECB-infested stems. In 2001, ECB infestation reduced the average mass of large tubers and increased the amount of small tubers in FL1867 and FL1879. In 2002, significant yield reductions were not observed. Across both years, ECB-infested plots produced fewer large (65- to 100-mm diam.) tubers than control plots. Other tuber properties and chip qualities were unaffected. This study indicates that second generation ECB infestation of approximately 30% infested plants results in economic loss for some chipping varieties and affects tuber bulking. In contrast to east coast growers, Midwest potato farmers must be concerned with second generation ECB.

Transgenic lettuce seedlings carrying hepatitis B virus antigen HBsAg

The obtainment of transgenic edible plants carrying recombinant antigens is a desired issue in search for economic alternatives viewing vaccine production. Here we report a strategy for genetic transformation of lettuce plants (Lactuca sativa L.) using the surface antigen HBsAg of hepatitis B virus. Transgenic lettuce seedlings were obtained through the application of a regulated balance of plant growth regulators. Genetic transformation process was acquired by cocultivation of cotyledons with Agrobacterium tumefaciens harboring the recombinant plasmid. It is the first description of a lettuce Brazilian variety Vitória de Verão genetically modified.

Nutrition, dry matter accumulation and partitioning and phosphorus use efficiency of potato grown at different phosphorus levels in nutrient solution

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Overexpression of plant uncoupling mitochondrial protein in transgenic tobacco increases tolerance to oxidative stress

An Arabidopsis thaliana cDNA clone encoding a plant uncoupling mitochondrial protein (AtPUMP1) was overexpressed in transgenic tobacco plants. Analysis of the AtPUMP1 mRNA content in the transgenic lines, determined by Northern blot, revealed variable levels of transgene expression. Antibody probing of Western blots of mitochondrial proteins from three independent transgenic lines showed significant accumulation of AtPUMP1 in this organelle. Overproduction of AtPUMP1 in transgenic tobacco plants led to a significant increase in tolerance to oxidative stress promoted by exogenous hydrogen peroxide as compared to wild-type control plants. These results provide the first biological evidence for a role of PUMP in protection of plant cells against oxidative stress damage.

Root morphology and phosphorus uptake by potato cultivars grown under deficient and sufficient phosphorus supply

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Absorção de manganês em soja RR sob efeito do glifosate

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The promoter of a gene encoding an isoflavone reductase-like protein in coffee (Coffea arabica) drives a stress-responsive expression in leaves

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

CaPrx, a Coffea arabica gene encoding a putative class III peroxidase induced by root-knot nematode infection

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Expression of a new Bacillus thuringiensis Cry1Ia gene in Escherichia coli with strong activity against cotton pests

The control of cotton pests may be accomplished using Bacillus thuringiensis Cry proteins. For this purpose, the objective of this work was to evaluate the insecticidal activity of a new Cry1Ia protein against neonatal larvae of Spodoptera frugiperda and Anthonomus grandis. The complete cry1Ia gene, previously obtained by PCR with oligonucleotide primers based on the sequenced gene, was cloned into the vector pET28a(+), introduced into Escherichia coli BL21(DE3) and expressed by induction with IPTG. The expression of the Cry1Ia protein was confirmed with molecular weight of approximately 81 kDa. The results demonstrated the efficiency of the bacterial system for the expression of B. thuringiensis Cry1Ia protein, which was subsequently used in quantitative bioassays against S. frugiperda and A. grandis larvae, resulting in an extremely toxic protein for both species. This characteristic is exceptionally important for obtaining transgenic cotton plants resistant to these pests.

Aplicação de silício solúvel via solo e foliar na cultura da batata (Solanum tuberosum l.) sob deficiência hídrica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)