scholarly journals Insights into the Mechanisms of Heat Priming and Thermotolerance in Tobacco Pollen

2021 ◽  
Vol 22 (16) ◽  
pp. 8535
Author(s):  
Lavinia Mareri ◽  
Claudia Faleri ◽  
Iris Aloisi ◽  
Luigi Parrotta ◽  
Stefano Del Duca ◽  
...  
Keyword(s):  
Male Gametophyte ◽  
Pollen Viability ◽  
Soluble Sugars ◽  
Pollen Grains ◽  
Tube Length ◽  
Metabolic Enzyme ◽  
Antioxidant Systems ◽  
Physiological Status ◽  
Crop Species ◽  
Tobacco Pollen

Global warming leads to a progressive rise in environmental temperature. Plants, as sessile organisms, are threatened by these changes; the male gametophyte is extremely sensitive to high temperature and its ability to preserve its physiological status under heat stress is known as acquired thermotolerance. This latter can be achieved by exposing plant to a sub-lethal temperature (priming) or to a progressive increase in temperature. The present research aims to investigate the effects of heat priming on the functioning of tobacco pollen grains. In addition to evaluating basic physiological parameters (e.g., pollen viability, germination and pollen tube length), several aspects related to a correct pollen functioning were considered. Calcium (Ca2+) level, reactive oxygen species (ROS) and related antioxidant systems were investigated, also to the organization of actin filaments and cytoskeletal protein such as tubulin (including tyrosinated and acetylated isoforms) and actin. We also focused on sucrose synthase (Sus), a key metabolic enzyme and on the content of main soluble sugars, including UDP-glucose. Results here obtained showed that a pre-exposure to sub-lethal temperatures can positively enhance pollen performance by altering its metabolism. This can have a considerable impact, especially from the point of view of breeding strategies aimed at improving crop species.

scholarly journals Pollen treatment in high osmotic potential: a simple tool for in vitro preservation and manipulation of viability in gametophytic populations

2002 ◽  
Vol 14 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Leandro Lopes Loguercio
Keyword(s):  
Osmotic Potential ◽  
Culture Media ◽  
Pollen Viability ◽  
Regression Line ◽  
Pollen Grains ◽  
Pollen Storage ◽  
Tobacco Pollen ◽  
In Vitro Preservation ◽  
Potential Applications

A method for in vitro preservation and manipulation of pollen viability based on simple changes in osmotic potential (sucrose concentrations) in culture media was developed using tobacco pollen as the experimental model. High osmotic potentials were capable of reversibly inhibiting pollen germination, preserving its viability at room temperature for long periods, as assessed by subsequent incubation in germination medium. When pollen was pre-germinated for different periods and subsequently incubated in 80 % sucrose medium (inhibiting medium) there was a progressive decrease in its viability, which was a trend best described by a quadratic regression line. Nevertheless, very small variations in pollen-tube lengths and viable pollen grains more resistant to the pre-germination step were detected by this procedure. Consequences and potential applications of these findings were discussed for use in analyses of variability, selection in gametophytic populations and pollen storage.

scholarly journals Pollen viability in Quercus robur L.

2017 ◽  
Vol 69 (1) ◽  
pp. 111-117 ◽  
Author(s):  
Branislava Batos ◽  
Danijela Miljkovic
Keyword(s):  
Pollen Tube ◽  
Quercus Robur ◽  
Interindividual Variability ◽  
Germination Rate ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Pollen Grain ◽  
Tube Length ◽  
Pedunculate Oak ◽  
Pollen Tube Length

The variability of viability (germination rate and the length of pollen tubes) of fresh pedunculate oak (Quercus robur L.) pollen grains was studied in vitro on a medium containing 15% sucrose. Spatial variability was studied by sampling fresh pollen grains from a total of thirteen trees at four different sites in the area of Belgrade (Kosutnjak, Banovo Brdo, Ada Ciganlija and Bojcin Forest) in a single year (2011). In order to assess temporal variability and determine the effects of climate change on a small time scale, we studied the viability of the pollen grains collected from one tree at the Banovo Brdo site in six different years (2004, 2005, 2006, 2007, 2011 and 2012). Interindividual variability was tested on the pollen grains sampled from eight trees at Ada Ciganlija in 2004. The percentage values of the pollen grain germination rate and the pollen tube length showed no statistically significant differences between the sites. However, the studied characteristics of the pollen grain viability (germination rate and pollen tube length) showed statistically significant differences in both temporal (between the pollen collection years) and interindividual variability. This type of research makes a valuable contribution to pedunculate oak breeding programs through the identification of trees with stable production and a good quality of pollen. Furthermore, it can be important in defining the patterns of spatial, temporal and individual variability of pollen grain viability under the influence of climate factors, which are showing compelling changing trends from year to year.

scholarly journals Intrapopulation variability for male gametophyte traits in the tomato F3 and F4 offspring derived from high temperature resistant F2 recombinants

2019 ◽  
pp. 37-43
Author(s):  
Milania D. Маkоvеi
Keyword(s):  
High Temperature ◽  
Male Gametophyte ◽  
Selection Process ◽  
Pollen Viability ◽  
Pollen Tubes ◽  
High Temperature Stress ◽  
Tube Length ◽  
Intrapopulation Variability ◽  
Average Variation ◽  
High Level

Relevance Identification of forms resistant to thermal stress is important not only at the stage of search, but also later in the selection process. Methods The paper presents the results obtained during the studies on the variability of tomato male gametophyte traits (pollen viability, pollen tube length, pollen resistance and resistance along pollen tubes) in the hybrid F2, F3 and F4 offspring derived from different crossing combinations strongly resistant to high temperature stress (8 hybrid combinations). Results Recombination differences expressed in the values of average variation per family (S2) have been found in the F2 populations segregated for a complex of pollen traits, which made it possible to isolate transgressive recombinants from different hybrid combinations, to produce seeds from them and to further perform selection cycles in F3. It has been found that high intrapopulation variability of male gametophyte traits is preserved in F3 and F4 offspring, which reflects the response of their genotypes to high temperature. The offspring derived from the best F2 recombinants has been shown to not preserve a high level of resistance in F3 and F4. As for the pollen heat resistance, the actual shift of the trait values in F3 in relation to F2 made 0.92, while it made 0.65 in F4 in relation to F2. The shift of the values in the dynamics of the F2, F3 and F4 generations from different hybrid combinations was somewhat higher for the resistance of pollen tubes making 0.99 (F3/F2) and 1.15 (F4/F2). The most pronounced positive shift towards high values in F3 and F4 in relation to F2 was recorded just in three combinations, L7 x L305, L7 x cv. Ceros, L7 x cv. Lider (R – 1.91; 1.29 and 1.08, respectively). High variability in the populations of F4 offspring is observed for quantitative traits, as well, namely, inflorescence number per plant, flower number per inflorescence, the number of set fruits per inflorescence and seed number in fruits. The differences in the offspring diversity found during estimation of the segregating F2 populations derived from different crossing combinations for the variability range have not been confirmed in F3 and F4.

scholarly journals Morphofunctional characteristics of the tomato male gametophyte under conditions of viral pathogenesis

2021 ◽  
pp. 16-21
Author(s):  
T. I. Saltanovish ◽  
L. I. Andronic ◽  
L. P. Antosh ◽  
A. N. Doncila
Keyword(s):  
Male Gametophyte ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Pollen Tubes ◽  
Viral Pathogenesis ◽  
Plant Genome ◽  
Experiment Control ◽  
High Level ◽  
Pollen Flowers

Relevance. The action of viral phytopathogens changes the quality of the male gametophyte, which ultimately leads to a decrease in plant productivity. So, information on the features of the variability of morphofunctional characteristics of the microgametophyte becomes topical. Taking into account the expression of a part of the plant genome in pollen, the male gametophyte can be used as a reliable system for assessing the response of genotypes to the action of viral pathogens. Presuming that the problems of variability of characteristics of the male gametophyte in conditions of viral pathogenesis have not been enough studied, as well as the main factors determining the variability have not been identified, the aim of the research was to study the effect of viral phytopathogens on the male gametophyte characters in tomato.Material and methods. Hybrids F1 and varieties of tomato were used in the experiments. Plants were grown in a greenhouse. They were inoculated with tobacco mosaic virus (TMV) or tomato aspermia virus (TAV) in the 4-5 leaf phase. To determine the quality of pollen, flowers of control and infected plants were collected; pollen was isolated and sown on a nutrient medium. The preparations were analyzed under microscope. The viability of the pollen and the length of the pollen tubes were assessed, and the ratio of these indicators was calculated.Results. Infection of plants with viruses changes some functional characteristics of the male gametophyte. The responses manifested as stimulation, inhibition, or neutral effect. The main sources of variability in characters of pollen were the genotype and viral agents. In viral pathogenesis, unequal indicators of pollen grains were found in terms of the rate of germination and growth of pollen tubes (PT). Analysis of the heritability coefficients of the ratio of pollen viability and PT length (experiment / control) revealed positive dominance and overdominance in 70% of cases. Genotypes have been identified that combine a high level of viability when infected with different viruses. The prospect of their use in further research is proposed. 

scholarly journals ОСОБЕННОСТИ РАЗВИТИЯ МУЖСКОГО ГАМЕТОФИТА СОСНЫ ОБЫКНОВЕННОЙ PINUS SILVESTRIS L. В УСЛОВИЯХ ГОРОДСКОЙ СРЕДЫ

2016 ◽  
Vol 6 (01) ◽  
pp. 390-408
Author(s):  
L.P. Khlebova ◽  
O.V. Bychkova
Keyword(s):  
Urban Environment ◽  
Male Gametophyte ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Weather Conditions ◽  
Pollen Tubes ◽  
Biological Indicator ◽  
Histochemical Staining ◽  
Pinus Silvestris ◽  
Germinated Pollen

<p>The peculiarities of the development of the male gametophyte of Pinus silvestris L. in the urban environment were studied. Quality of pollen was evaluated by laboratory experiments through germination at the nutrient medium and by histochemical staining to determine the presence of redox enzymes. It was shown that pollen viability is closely linked to climatic and weather conditions during the period of microsporogenesis and mass pollination. Atmospheric pollution affected the pollen significantly. Low temperatures and high humidity in the background of the weak capacity of self-purification of the atmosphere led to a reduction of the potential pollen viability. The ability of the pollen grains to germinate was reduced, the number of abnormal pollen tubes was increased, and the proportion of cells containing active peroxidase was decreased. We revealed a close positive correlation between the frequency of germinated pollen grains and the presence of active peroxidase, as well as a negative correlation between the percentage of colored pollen and the frequency of pollen tube anomalies, which confirmed the role of peroxidase activity not only in the induction of pollen germination, but also the formation of pollen tubes.<br />A ranking of the urban territory on the strength of unfavorable environmental factors has been carried out. The reaction of male gametophyte of pine allowed us to consider it as a biological indicator of unfavorable ecological situation in the urban environment.</p>

scholarly journals SCREENING CAPSICUM GENOTYPES FOR INCREASED DROUGHT TOLERANCE BY IN VITRO POLLEN GERMINATION AND POLLEN TUBE LENGTH

2020 ◽  
Vol 23 (1) ◽  
pp. 52-58
Author(s):  
Y. Arnaoudova ◽  
B. Arnaoudov
Keyword(s):  
Drought Tolerance ◽  
Pollen Fertility ◽  
Pollen Germination ◽  
Male Gametophyte ◽  
Pollen Viability ◽  
Pollen Tubes ◽  
Tube Length ◽  
Vegetable Crops ◽  
Lower Productivity

Yield realizing in vegetable crops depends on several reproductive processes that include pollen fertility as well as pollen tubes germination and growth. The study was conducted as the pollen characteristics fertility and viability were used, as well as the productivity for evaluation of drought tolerance in four pepper genotypes Capsicum annuum L. From the conducted cytological analyses was found that decreasing the water standard with 50% exert negative influence over the male gametophyte and the pollen fertility decreases with up to 37.4% average. More sensitive to drought showed to be the plants from both cultivars Pazardzhishka kapia and Albena, in which lower productivity and lower restorable potential were found in comparison with those found in the mutant lines No.1936 and No.1917. Increased tolerance showed the male gametophyte of line No.1936. After a drought in it were found the highest values for pollen viability – 33.4% average pollen germination and 438.7µm pollen tubes length which was with proven mathematical difference compared with the rest of the genotypes. These results showed that pollen fertility analyses and pollen viability analyses in drought plants could be used for evaluation of the drought tolerance.

scholarly journals A Duplicated Copy of the Meiotic Gene ZIP4 Preserves up to 50% Pollen Viability and Grain Number in Polyploid Wheat

Biology ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 290
Author(s):  
Abdul Kader Alabdullah ◽  
Graham Moore ◽  
Azahara C. Martín
Keyword(s):  
Pollen Viability ◽  
Pollen Grains ◽  
Wheat Chromosome ◽  
Grain Number ◽  
Meiotic Gene ◽  
Chromosome 5B ◽  
Mutant Pollen ◽  
Female Gametogenesis ◽  
Chromosome 3B

Although most flowering plants are polyploid, little is known of how the meiotic process evolves after polyploidisation to stabilise and preserve fertility. On wheat polyploidisation, the major meiotic gene ZIP4 on chromosome 3B duplicated onto 5B and diverged (TaZIP4-B2). TaZIP4-B2 was recently shown to promote homologous pairing, synapsis and crossover, and suppress homoeologous crossover. We therefore suspected that these meiotic stabilising effects could be important for preserving wheat fertility. A CRISPR Tazip4-B2 mutant was exploited to assess the contribution of the 5B duplicated ZIP4 copy in maintaining pollen viability and grain setting. Analysis demonstrated abnormalities in 56% of meiocytes in the Tazip4-B2 mutant, with micronuclei in 50% of tetrads, reduced size in 48% of pollen grains and a near 50% reduction in grain number. Further studies showed that most of the reduced grain number occurred when Tazip4-B2 mutant plants were pollinated with the less viable Tazip4-B2 mutant pollen rather than with wild type pollen, suggesting that the stabilising effect of TaZIP4-B2 on meiosis has a greater consequence in subsequent male, rather than female gametogenesis. These studies reveal the extraordinary value of the wheat chromosome 5B TaZIP4-B2 duplication to agriculture and human nutrition. Future studies should further investigate the role of TaZIP4-B2 on female fertility and assess whether different TaZIP4-B2 alleles exhibit variable effects on meiotic stabilisation and/or resistance to temperature change.

scholarly journals High temperatures during microsporogenesis fatally shorten pollen lifespan

2021 ◽  
Author(s):  
Maurizio Iovane ◽  
Giovanna Aronne
Keyword(s):  
Experimental Data ◽  
Heat Treatment ◽  
Heat Stress ◽  
High Temperature ◽  
Male Gametophyte ◽  
Crop Productivity ◽  
Anther Dehiscence ◽  
Optimal Temperature ◽  
Drastic Reduction ◽  
Crop Species

AbstractMany crop species are cultivated to produce seeds and/or fruits and therefore need reproductive success to occur. Previous studies proved that high temperature on mature pollen at anther dehiscence reduce viability and germinability therefore decreasing crop productivity. We hypothesized that high temperature might affect pollen functionality even if the heat treatment is exerted only during the microsporogenesis. Experimental data on Solanum lycopersicum ‘Micro-Tom’ confirmed our hypothesis. Microsporogenesis successfully occurred at both high (30 °C) and optimal (22 °C) temperature. After the anthesis, viability and germinability of the pollen developed at optimal temperature gradually decreased and the reduction was slightly higher when pollen was incubated at 30 °C. Conversely, temperature effect was eagerly enhanced in pollen developed at high temperature. In this case, a drastic reduction of viability and a drop-off to zero of germinability occurred not only when pollen was incubated at 30 °C but also at 22 °C. Further ontogenetic analyses disclosed that high temperature significantly speeded-up the microsporogenesis and the early microgametogenesis (from vacuolated stage to bi-cellular pollen); therefore, gametophytes result already senescent at flower anthesis. Our work contributes to unravel the effects of heat stress on pollen revealing that high temperature conditions during microsporogenesis prime a fatal shortening of the male gametophyte lifespan.

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

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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