Changes of Enzyme Activity During Pollen Germination in Maize, and Possible Evidence of Lignin Synthesis

1997 ◽  
Vol 24 (3) ◽  
pp. 329 ◽  
Author(s):  
Zin-Huang Liu ◽  
Mang-Jye Ger

During pollen germination in Zea mays L., the activity of phenylalanine ammonia-lyase and peroxidases increased, accompanied by a decline of phenolic compounds. Levels of IAA decreased dramatically as the pollen germinated, and this decline was correlated with enhanced IAA oxidation activity by IAA oxidase in the germinated pollen. The cationic peroxidase isozymes (pI 9.0) with estimated molecular mass of 45 kDa may be involved in lignin polymerisation in the pollen cell wall.

1970 ◽  
Vol 11 ◽  
pp. 47-50
Author(s):  
Tul Bahadur Poon ◽  
TM Rao ◽  
C Aswath ◽  
PE Rajasekharan ◽  
DP Kumar

Fresh pollen of 16 promising genotypes of gladiolus was tested for their pollen viability. Modified cellophane method was employed to assess the pollen viability. Pollen germination media consisted of 15% sucrose supplemented with 300 ppm calcium nitrate, 200 ppm magnesium sulphate, 100 ppm potassium nitrate and 100 ppm boric acid. Highly significant variations were observed for percentage of pollen germination, non-germinated pollen and sterile pollen. The highest pollen germination (76.41%) was in genotype Hybrid selection 88-10-22, and did not differ significantly from Gladiolus callianthus (75.41%), Sapna (75.10 %), Hybrid selection 86-32-11, (73.28 %), Kum Kum (69.41%), Poonam (69.22 %), Hybrid selection 87-22-1 (67.87 %), Hybrid selection 87-1-1 (67.61 %), Psittacinus hybrid (64.64%) and Darshan (63.97%). The lowest non- germinated pollen (10.47%) was in genotype Gladiolus callianthus, and insignificantly followed by Hybrid selection 88-10-22 with 18.77 % and Hybrid selection 87-22-1 with 18.95 %. The lowest percentage of sterile pollen was noticed in genotype Sapna (2.82%) followed by Poonam with 4.00 % Hybrid selection 88-10-22 with 4.82% and Hybrid selection 82-11-27 with 5.22%. Key words: Gladiolus; germination; pollen DOI: 10.3126/njst.v11i0.4089Nepal Journal of Science and Technology 11 (2010) 47-50


2020 ◽  
Vol 9 (10) ◽  
pp. e7199108992
Author(s):  
Dalilla Carvalho Rezende ◽  
Dayson Fernando Ribeiro Brandão ◽  
Simone Cristiane Brand ◽  
Silvia Blumer ◽  
Sérgio Florentino Pascholati ◽  
...  

This work aimed to evaluate the potassium phosphite-based commercial product, Phytogard®, as a complementary tool for the management of gummosis in citrus. Seedlings of tangerine ‘Sunki’ were sprayed at concentrations 0; 0.5; 2 and 5 mL L-1 of Phytogard® and subsequently inoculated with zoospores of Phytophthora nicotianae. The disease incidence was reduced by 84% in plants sprayed at the concentration 0.5 mL L-1 and the plants sprayed at concentrations of 2 and 5 mL L-1 showed zero disease incidence. There was increased an production of fresh matter of shoot and roots in plants sprayed and inoculated with the pathogen compared to unsprayed plants. Plants sprayed with Phytogard® and inoculated with the pathogen showed lower values for total phenols, enzyme activity for phenylalanine ammonia-lyase and peroxidase and for total protein content in root tissues compared to non-inoculated plants. There was higher activity of the enzyme β 1.3-glucanase in root tissues of plants inoculated with the pathogen that received the product at the concentration of 2 mL L-1. The results of this study showed that the potassium phosphite-based product Phytogard® has potential for the control of Phytophthora nicotianae in seedlings of tangerine ‘Sunki’. However, it is not possible to conclude that this control occurs through resistance induction.


2021 ◽  
Vol 7 (3) ◽  
pp. 64-69
Author(s):  
L. Bayramov

Abstract. The zones of distribution of varieties and forms of quince on the territory of the Nakhchivan Autonomous Republic have been established, phenological observations have been carried out, their flowering and fruiting have been studied. On the territory of the Autonomous Republic, flowering of varieties and forms of quince begins in the second decade of April, depending on the distribution zone, with an average daily temperature of 12–13 °C and lasts 12–13 days, depending on weather conditions. Each flower has 10–12 stamens arranged in one row. The article also studied the viability of pollen in a number of quince varieties. Pollen viability was studied in the varieties Sary, Tursh, Ordubad, Gara and wild forms. Pollen fertility was determined by staining with acetocarmine. Pollen germinates in 2–5–10–15 and 20% glucose solution. Counting of germinated pollen grains was carried out under a microscope. The study showed that of all the experimental varieties, the pollen fertility of the Sary quince and Tursh quince varieties is high (up to 96.6–97.1%). The best medium for the germination of quince pollen is a 10–15% glucose solution. Pollen germination in this solution reaches 47.4–88.0%. In distilled water (control), the germination of quince pollen reached from 9.7% to 35.6% for varieties. Quince pollen remains viable for 31–43 days.


2005 ◽  
Vol 32 (3) ◽  
pp. 267 ◽  
Author(s):  
N. P. Geetha ◽  
K. N. Amruthesh ◽  
R. G. Sharathchandra ◽  
H. S. Shetty

Phenylalanine ammonia lyase (PAL) activity was studied in pearl millet cultivars with different levels of resistance to the downy mildew disease caused by Sclerospora graminicola, an important oomycete pathogen. PAL activity was elevated in resistant host cultivar and decreased in susceptible cultivars following downy mildew pathogen infection. The enzyme activation varied between cultivars and was correlated with the degree of resistance to downy mildew disease. The induction of PAL as a response to pathogen inoculation was further corroborated by a time-course study in seedlings and cultured cells of pearl millet. The level of PAL activity was highest at 1.5 h in cultured cells and 4 h in seedlings of resistant host cultivar after inoculation with Sclerospora graminicola. Further studies on PAL activity in different tissues of seedlings showed highest enzyme activity in the young growing region of the root of the resistant host cultivars. The accumulation of wall-bound phenolics and lignin was higher in the resistant cultivar seedlings as evidenced by phloroglucinol–HCl staining and p-coumaric acid assay. The temporal changes in lignin concentration and the concentration of soluble phenolics were greater in root tissues of resistant cultivars than in those of susceptible cultivars. Treatment of resistant seedlings with a PAL inhibitor, α-aminooxy-β-phenylpropionic acid, resulted in the enhancement of the enzyme activity, whereas in the presence of 1 mm trans-cinnamic acid the pathogen-induced PAL was completely inhibited. Treatment of pearl millet seedlings with exogenously applied PAL inhibitors induced downy mildew disease susceptibility in the resistant pearl millet cultivar, consistent with direct involvement of PAL in downy mildew resistance. Results are discussed with respect to the presumed importance of host phenolic compounds and lignin accumulation and its relation to PAL activation as a response to the pathogen infection.


2020 ◽  
Vol 39 (9) ◽  
pp. 1185-1197
Author(s):  
Mohsin Abbas Zaidi ◽  
Stephen J. B. O’Leary ◽  
Christine Gagnon ◽  
Denise Chabot ◽  
Shaobo Wu ◽  
...  

2018 ◽  
Vol 130 ◽  
pp. 334-344 ◽  
Author(s):  
Silvia E. Langer ◽  
Natalia C. Oviedo ◽  
María Marina ◽  
José Luis Burgos ◽  
Gustavo A. Martínez ◽  
...  

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