Excess Boron Reduces Polyphenol Oxidase Activities in Embryo and Endosperm of Maize Seed during Germination

2007 ◽  
Vol 62 (1-2) ◽  
pp. 111-115 ◽  
Author(s):  
Hülya Ölçer ◽  
İsmail Kocaçalışkan

The effects of increasing concentrations of boron (0, 0.1, 1, 10 and 20 mм) as boric acid on the rate of germination and polyphenol oxidase activities in embryo and endosperm tissues of maize seeds (Zea mays L. cv. Arifiye) were studied. The germination percentage of maize seeds was not affected by boron concentrations up to 10 mм, and decreased by 20 mм. Distilled water and lower boron concentrations (0.1 and 1 mм) increased polyphenol oxidase activities at the beginning of germination up to 12 h whereas its excess levels (10 and 20 mм) decreased polyphenol oxidase activities in embryos and endosperm during germination. Polyphenol oxidase activities with o-diphenolic substrates (caffeic acid, catechol and dopa) were found to be higher than with a monophenolic substrat (tyrosine) in both embryos and endosperms. Further, caffeic acid oxidizing polyphenol oxidase was found to show more activity in embryos of the seeds germinating in distilled water when compared to other substrates.

2015 ◽  
Vol 67 (3) ◽  
pp. 993-1000 ◽  
Author(s):  
Lydia Shtereva ◽  
Roumiana Vassilevska-Ivanova ◽  
Tanya Karceva

An experiment was carried out hydroponically under laboratory conditions to investigate the effect of salt stress on several physiological and biochemical parameters of three sweet corn (Zea mays L. var. saccharata) genotypes: lines 6-13, C-6 (pollen source) and their heterotic F1 hybrid ?Zaharina?. The degree of salinity tolerance among these genotypes was evaluated at three different sodium chloride (NaCl) concentrations: 0 mM, 100 mM, 125 mM and 150 mM. Seed germination, plant growth and biochemical stress determining parameters such as malondialdehyde (MDA), proline content and hydrogen peroxide (H2O2) levels were compared between seedlings of lines and hybrid. The obtained results indicated that both lines and hybrid have similar responses at different salinity levels for all examined traits. All the seedlings? growth parameters, such as germination percentage, root length, shoot length, root and shoot fresh and dry weight, decreased with increasing salinity level. MDA, proline and H2O2 increased at different saline conditions in comparison to the control. Based on the results, of the three genotypes examined, the hybrid Zaharina, followed by line C-6, was more salt-sensitive than line 6-13 in salt stress condition.


2003 ◽  
Vol 4 (1) ◽  
Author(s):  
G. M. CIRIO ◽  
M. L. R. Z. C. LIMA

O gênero Aspergillus tem como característica desenvolver-se em sementes e grãos com baixa umidade causando deterioração destes durante armazenamento com efeito na germinação nas sementes e produção de micotoxinas como aflatoxina em grãos, prejudiciais a saúde do homem e dos animais. Para avaliar a eficiência de métodos de detecção para Aspergillus, verificar germinação e umidade das sementes de milho foi feita armazenagem por 270 dias. As avaliações foram ao zero, 90, 150, 210 e 270 dias após armazenamento (DAA) com testes em papel filtro (blotter) e nos meios de batata dextrose ágar ácido (BDA ácido) e ágar suco de tomate mais 6% de cloreto de sódio (AST salino). Como resultados ao zero dia de armazenamento verificou-se ausência de Aspergillus; aos 90 DAA incidências 7,2% em blotter e 1,1% em AST; aos 150 DAA incidências 5,1% em blotter; aos 210 DAA incidências 41,1% em AST, 5,1% no blotter e 3,3% no BDA e aos 270 DAA incidências de 79,7% e 66,2% em blotter e AST que não diferiram estatisticamente entre si e 21% em BDA. A germinação e umidade foram: 98% e 10,8% (dia zero); 93% e 13,4% (90 DAA); 93% e 12,2% (150 DAA); 92% e 14,2% (210 DAA) e 36 % e 12,2 % (270 DAA), respectivamente. Concluiu-se que o meio AST salino mostrou maior eficiência para detectar Aspergillus aos 210 DAA indicando proliferação do gênero durante armazenamento até 270 DAA. A germinação das sementes reduziu-se de 92% para 36% entre 210 e 270 DAA e a umidade variou entre 10,8% e 14,2%, compatível com armazenagem segura. DETECTION METHODS OF Aspergillus GENUS IN CORN SEEDS (Zea mays L.) DURING 270 DAYS STORAGE Abstract The genera Aspergillus has a characteristic to developed in seeds and grains with low humidity causing deterioration during storage with effects on the seeds germination andmicotoxins production as aflatoxin in grains that are harmful to man and animal health. To evaluated the efficiency of detection methods for Aspergillus, to confirm germination and humidity in maize seeds, they were stored for 270 days. The evaluations were at zero, 90, 150, 210 and 270 days after storage (DAS) with the blotter test and in media potato-dextrose-agar (PDA acid) and tomato juice agar plus 6% NaCl (salty TJA). As results at zero day absence of Aspergillus, at 90 DAS incidence 7,2% in blotter and 1,1% in TMA, at 150 DAS incidence 5,1% in blotter; at 210 DAS the incidence 41,1% in TMA, 5,1% in blotter e 3,3% in PDA and at 270 DAS incidence 79,7% and 66,2% in blotter and TMA that didn’t differ statistically and 21% in PDA. Were get germination and humidity 98% and 10,8% (zero day); 93% and 13,4% (90 DAS); 93% and 12,2% (150 DAS); 92% and 14,2% (210 DAS) and 36% and 12,2% (270 DAS) respectively. The conclusions were that the media salty TJA showed higher efficiency to detect Aspergillus at 210 DAS what indicated proliferation of the genera during storage till 270 DAS. The germination reduced from92% to 36% between 210 e 270 DAS and humidity remained between 10,8% and 14,2% compatible with secure storage.


Nematology ◽  
2015 ◽  
Vol 17 (6) ◽  
pp. 667-670
Author(s):  
Pedro Marcus de Souza Confort ◽  
Mário M. Inomoto

The objective of this study was to evaluate the effects of maize (Zea mays) seed treatments for the control of Pratylenchus zeae under glasshouse conditions. Seeds of the maize hybrid DKB390 treated with thiametoxam, thiametoxam + abamectin and imidacloprid + thiodicarb were used as treatments. The treated maize seeds were sown in plastic cups containing soil inoculated with 200 nematodes (juveniles and females). Two of the four experiments that were done were evaluated at 60 and 90 days after sowing (DAS). The first experiment was evaluated 30, 60 and 90 DAS, and the fourth experiment only at 90 DAS. Fresh root mass and total nematodes extracted and counted from roots of each plant were used as the assessment criteria. All seed treatments tested showed a degree of efficacy in reducing the reproduction rates of P. zeae under glasshouse conditions. The imidacloprid + thiodicarb treatment showed consistent results in all replications of all four experiments, often being the one resulting in the lowest P. zeae density. The thiametoxam + abamectin treatment was also effective in reducing nematode numbers and differed significantly from the control treatments for all four experiments. Thiametoxam used on its own as a seed treatment proved to be as effective as the mixture with abamectin in two of the four experiments and does not provide consistent results in terms of reducing P. zeae population levels.


Agrologia ◽  
2018 ◽  
Vol 1 (1) ◽  
Author(s):  
M. K Lesilolo ◽  
Jacob Patty ◽  
N. Tetty

This study was aimed to determine the proper dose of ash desiccant on maize seed stored for 30, 60 and 90 days. The design used was a Completely Randomized Factorial Design, with two factors and three replications.  The first factor was desiccant dose (D) : Do = 0 % (control), D1 = 5 % (12.5 g of seed weight), D2 = 10% (25 g of seed weight), D3 = 15 % (37 g of seed weight), D4 = 20 % (50 %g of seed weight), D5 = 25 % (62.5 g of seed weight).  The second factor was length of storage (S) : S1 = 30 day storage, S2 = 60 day storage and S3 = 90 day storage. The result show that use of desiccant only gave effect on the water content of seeds (12.31 %) and speed of seed growth vigor parameters (24.84 %).  Use of desiccant in 90 day storage were able to maintain water content of seeds (12.43 %), seed germination viability parameter (100 %), and vigor of seeds, which consisted of seed growth simultaneity (66.77 %) and seed growth speed (28.71 %).  The interaction between the use off ash desiccant and the length of storage had no effect on  viability and vigor of maize (Zea mays L) seeds but had an effect on their water content after storage (12.73%).


2016 ◽  
Vol 1 (1) ◽  
pp. 54 ◽  
Author(s):  
R. Sozharajan ◽  
S. Natarajan

Maize (Zea mays L.) is the world’s leading edible oil and third largest important cereal. In addition to it is used as food for human consumption as well as food grain for livestock. High concentrations of NaCl in soils account for large decrease in the yield of a large variety of crops all over the globe. The objective of the present study was conducted to evaluate NaCl stress on growth and mineral nutrient composition of maize plants. Maize seeds were grown in plastic pots having fine sand. After 20 days of germination, the plants were subjected to seven different concentrations (Control, 25mM, 50mM, 75mM, 100mM, 125mM and 150mM) of NaCl. Plants were analyzed on 15th day after salt treatment. Factorial experiments in a completely randomized design (CRBD) with three replications were applied. The growth parameters and mineral contents Na, Ca, K and Cl were investigated from saline treated and non saline treated plants. Results indicated that the NaCl stress markedly reduced the shoot and root length fresh and dry masses. Moreover Na+, Cl- content increased with increase in NaCl stress, while Ca2+ and K+ were decreased significantly.


2018 ◽  
Vol 17 (1) ◽  
pp. 37 ◽  
Author(s):  
RAFAEL PAREIRA DINIZ ◽  
IOLANDA VILELA VON PINHO ◽  
BRUNO DA COSTA PANIAGO ◽  
EDILA VILELA DE REZENDE VON PINHO ◽  
HELOISA OLIVEIRA DOS SANTOS ◽  
...  

RESUMO - Durante o processo de produção de sementes, estresses abióticos como salinidade do solo e déficit hídrico são fatores determinantes e que influenciam no estabelecimento e desenvolvimento uniforme do estande em campo. Nesse sentido, cultivares tolerantes a altas concentrações salinas nestas fases são fundamentais nos programas de melhoramento. Diante disto, objetivou-se com a presente pesquisa verificar a influência da produção de sementes sob condições de estresse hídrico e salino na germinação e no vigor, assim como na atividade da enzima α-amilase em sementes de milho. Para isso, foram conduzidos dois experimentos para a produção de sementes de milho, um em condições de estresse salino e o outro sob condições de déficit hídrico. Os experimentos foram conduzidos em delineamento de blocos completos casualisados, em esquema de parcelas subdivididas. As sementes colhidas em diferentes estádios de desenvolvimento, determinados pela linha de leite (LL), foram submetidas a análises fisiológicas e de vigor, bem como determinou-se a expressão da enzima α-amilase por eletroforese. Diante dos resultados foi possível concluir que a germinação e o vigor das sementes produzidas em solos com condutividade de 3 dS m-1 não são afetados pela salinidade, e o desenvolvimento das plantas em condições de estresse hídrico e salino não afetou a atividade da enzima α-amilase em sementes colhidas na LL5. Palavras-chave: Zea mays L., eletroforese, estádios de desenvolvimento. PHYSIOLOGICAL QUALITY AND ALPHA-AMYLASE EXPRESSION OF MAIZE SEEDS IN CONDITIONS OF SALT AND WATER STRESS ABSTRACT - During seed production process, abiotic stresses such as soil salinity and drought are determining factors that influence the establishment and development of uniform stand on the field. Thus, tolerant cultivars to high salt concentrations in these phases are critical in breeding programs. This way, we aimed to investigate seeds production in conditions of water and salt stress on maize seeds germination and vigor as well as the α-amylase enzyme activity. Two experiments were performed for maize seeds production in salt stress conditions and drought. The experiments were conducted in a randomized complete block design in a split-plot arrangement. Seeds harveste at different development stages, determined by milk line (ML), were submitted to vigor and physiological analysis as well as the expression determination of α-amylase enzyme by electrophoreses. With the results it was concluded that both, the seeds germination and vigor produced in soil with conductivity 3 dS m-1, are not affected by salinity, and the plants development in water and salt stress conditions did not affect the activity of α-amylase enzyme in seedsharvested in ML5 maturity stage. Keywords: Zea mays L., electrophoresis, development stages.


Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2421
Author(s):  
Canhong Gao ◽  
Mohamed S. Sheteiwy ◽  
Chen Lin ◽  
Yajing Guan ◽  
Zaid Ulhassan ◽  
...  

Chilling stress greatly inhibited the seed germination, plant growth, development and productivity in this study. The current research aimed to study the effects of different polyamine (PA) inhibitor combinations (Co), e.g., D-arginine (D-Arg), difluoromethylormithine (DFMO), aminoguanidine (Ag) and methylglyoxyl–bis-(guanyhydrazone) (MGBG) at different doses, i.e., 10 µM Co, 100 µM Co, 500 µM Co, 1000 µM Co and 1000 µM Co + 1 mM Spd (Spermidine) in two inbred lines of maize (Zea mays L.), i.e., Mo17 and Huang C, a sensitive and tolerant chilling stress, respectively. The combination treatments of PA inhibitors reduced the biosynthesis of putrescine (Put) in the tissues of both studied inbred lines. Application with 500 µM Co and 1000 µM Co did not result in a significant difference in Put concentrations, except in the coleoptile of Mo17. However, combining Spd to 1000 μM of PA inhibitors enhanced the Put, Spd, spermine (Spm) and total PAs in the roots, coleoptile and mesocotyls. Put and total PAs were increased by 39.7% and 30.54%, respectively, when Spd + 1000 µM Co were applied relative to their controls. Chilling stress and PA inhibitors treatments affected both inbred lines and resulted in differences in the PA contents. Results showed that enzymes involved in the biosynthesis of PAs (ornithine decarboxylase as ODC and S-adenosylmethionine decarboxylase as SAMDC) were significantly downregulated by 1000 µM Co in the tissues of both inbred lines. In contrast, the activity of PAO, a Pas degradation enzyme, was significantly improved by 1000 µM Co under chilling stress. However, Spd + 1000 µM Co significantly improved the activities of ODC and SAMDC and their transcript levels (ODC and SAMDC2). While it significantly downregulated the PAO activity and their relative genes (PAO1, PAO2 and PAO3) under chilling stress. Overall, this study elucidates the specific roles of Spd on the pathway of PA inhibitors and PA biosynthesis metabolism in maize seed development in response to chilling stress. Moreover, the Huang C inbred line was more tolerant than Mo17, which was reflected by higher activities of PA biosynthesis-related enzymes and lower activities of PAs’ degradative-related enzymes in Huang C.


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