scholarly journals Effects of Salinity on the Development of Hydroponically Grown Borage (Borago officinalis L.) Male Gametophyte

2013 ◽  
Vol 41 (1) ◽  
pp. 65 ◽  
Author(s):  
Firoozeh TORABI ◽  
Ahmad MAJD ◽  
Shekoofeh ENTESHARI ◽  
Saeed IRIAN ◽  
Mohammad NABIUNI

In this research, the effect of salinity on the development of anther in hydroponically-grown borage was studied. Plants grown on hydroponic media are rapidly and transiently stressed. The overall objective of this research was to elucidate the microscopic effects of salinity on the formation, development, and structure of anthers. Flowers, at different developmental stages, were removed, fixed in FAA, embedded in paraffin, and cut into 7-10 μm slices using a microtome. Staining was carried out with Hematoxylin-Eosine, and the developmental stages of the control and NaCl-treated plants were compared. In control plants young anther consisted of 4 pollen sacs. Anther wall development followed the typical dicotyledonous pattern and was composed of an epidermal layer, an endothecium layer, and the tapetum. Microspore tetrads were tetrahedral. Salinity caused certain abnormalities during pollen developmental processes, such as the destruction of the anther wall and both the degeneration and production of abnormal pollen grains. A decrease in plant fecundity, which involves aborting pollen, followed by a change in resource from reproductive activities to metabolic reactions is possibly a general response to the deleterious effects of salinity.

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1117A-1117
Author(s):  
Chantalak Tiyayon ◽  
Anita Nina Azarenko

Pollen development is an important event in plant reproduction. Hazelnut (Corylus avellana) male flower differentiation starts in summer and pollen shed is in the winter. Hazelnut pollen shed can vary up to 3 months between early to late flowering genotypes. Microsporogenesis and microgametogenesis of hazelnut is not well understood. Pollen development and differentiation of nine genotypes, representing early to late blooming cultivars from the National Clonal Germplasm Repository in Corvallis, Ore., were studied. Catkins were collected weekly from Aug. to Nov. 2002. Tissue sections were examined under the light microscope. Microsporogenesis was divided into five stages: archesporial cells, sporogenous cells and parietal layers, pollen mother cells (PMC), tetrads, and microspores. Microgametogenesis was distinguished between young pollen grains (uninucleate) and mature pollen grains (binucleate). On 4 Aug., cultivars were at different developmental stages of microsporogenesis. Early blooming cultivars had PMCs present. Later-blooming cultivars only contained archesporial cells. PMCs were present in all cultivars by 22 Aug. Microspores were observed on 26 Sept. in all cultivars. This study contributes to a better understanding of male gametophyte development in hazelnut, which has increased our ability to correlate hazelnut pollen development with bloom phenology.


2012 ◽  
Vol 4 (1) ◽  
pp. 31-43 ◽  
Author(s):  
Özlem AYTÜRK ◽  
Meral ÜNAL

Male (staminat) flower development, being separated in 8 phases, was investigated in Laurus nobilis (Lauraceae) through the usage of histological sections and scanning electron microscopy (SEM) analysis. Flower development starts when apical meristem differentiates, followed by the conversion of this structure to floral meristem. Initial development phases comprise incidents similar to the ones of the female flower. 4 tepals and 8-10 stamens primordia develop through floral meristem in turn. In early stages of the development, sexual dimorphism occurs when the carpel primordium arrests. Filaments carry 2 nectaries in stamens which arise in 3 whorls. Anther wall consists of epidermis, endothecium, 2 or 3 middle layers and a single-layered glandular tapetum. Anthers are bisporangiate. Meiotic division is regular in pollen mother cells, and pollen grains do not contain aperture. Beside the pollen scattered individually within the pollen sacs, groups which contain some pollen tied to each other are rarely observed, as well. Pollen grains seldom germinate within microsporangium. Anthers are opened with 2 valves which widen from the base through the top. Accumulation of polysaccharides, lipids and proteins were identified by histochemical methods in stamens. These organic substances are greater within and around the vascular bundle compared to other tissues.


2010 ◽  
Vol 70 (2) ◽  
pp. 351-360 ◽  
Author(s):  
AT. Nakamura ◽  
HM. Longhi-Wagner ◽  
VL. Scatena

Anther and pollen development were studied in Olyra humilis Nees, Sucrea monophylla Soderstr, (Bambusoideae), Axonopus aureus P. Beauv., Paspalum polyphyllum Nees ex Trin. (Panicoideae), Eragrostis solida Nees, and Chloris elata Desv. (Chloridoideae). The objective of this study was to characterise, embryologically, these species of subfamilies which are considered basal, intermediate and derivate, respectively. The species are similar to each other and to other Poaceae. They present the following characters: tetrasporangiate anthers; monocotyledonous-type anther wall development, endothecium showing annular thickenings, secretory tapetum; successive microsporogenesis; isobilateral tetrads; spheroidal, tricellular, monoporate pollen grains with annulus and operculum. Nevertheless, the exine patterns of the species studied are distinct. Olyra humilis and Sucrea monophylla (Bambusoideae) show a granulose pattern, whereas in the other species, it is insular. In addition, Axonopus aureus and Paspalum polyphyllum (Panicoideae) have a compactly insular spinule pattern, while Chloris elata and Eragrostis solida (Chloridoideae) show a sparsely insular spinule pattern. The exine ornamentation may be considered an important feature at the infrafamiliar level.


2012 ◽  
Vol 84 (4) ◽  
pp. 951-960 ◽  
Author(s):  
Nuran Ekici ◽  
Feruzan Dane

In this study, ultrastructures of anther wall and sporogenous tissue of Leucojum aestivum were investigated during different developmental stages. Cytomictic channels were seen between pollen mother cells during prophase I. Polar distribution was described in the organelle content of pollen mother cells and microspores in early phases of microsporogenesis and also in pollen mitosis. Active secretion was observed in tapetal cells. Previous reports about developmental stages of male gametophyte were compared with the results of this study.


Rodriguésia ◽  
2021 ◽  
Vol 72 ◽  
Author(s):  
Yanina de Jesús Pérez ◽  
Maria Betiana Angulo ◽  
Ana Honfi ◽  
Massimiliano Dematteis

Abstract Lessingianthus plantaginoides (Vernonieae, Asteraceae) is a small natural tetraploid shrub that inhabits rocky highlands from South America. The population studied inhabits and covers an extensive region of a private reserve with high local biodiversity and animal and plant endemisms. With the purpose of providing insights into the cyto-embryology of this tetraploid species, the aims of this study were: to perform an ontogenetic study of the male and female gametophytes of L. plantaginoides; to carry out detailed meiotic analysis and evaluate the fertility of this species; to document and provide highlights on taxonomic implications of their reproductive aspects. Lessingianthus plantaginoides presented the following male and female gametophyte traits: dicotyledonous type of anther wall development, tetrahedral tetrads, 3-celled mature pollen grains; development of the chalazal megaspore, monosporic embryo sac and Polygonum type of megagametophyte development. The meiotic behavior was regular, the spores were tetrads of equal size and the pollen grains were highly stainable. Lessingianthus plantaginoides is a highly diplodized autotetraploid that reproduces sexually and has high meiotic regularity; which is apparently responsible for its colonization potential. It now seems certain that polyploid speciation plays a significant role in the establishment and diversification of the genus.


2021 ◽  
Vol 22 (22) ◽  
pp. 12212
Author(s):  
Božena Klodová ◽  
Jan Fíla

Angiosperm mature pollen represents a quiescent stage with a desiccated cytoplasm surrounded by a tough cell wall, which is resistant to the suboptimal environmental conditions and carries the genetic information in an intact stage to the female gametophyte. Post pollination, pollen grains are rehydrated, activated, and a rapid pollen tube growth starts, which is accompanied by a notable metabolic activity, synthesis of novel proteins, and a mutual communication with female reproductive tissues. Several angiosperm species (Arabidopsis thaliana, tobacco, maize, and kiwifruit) were subjected to phosphoproteomic studies of their male gametophyte developmental stages, mostly mature pollen grains. The aim of this review is to compare the available phosphoproteomic studies and to highlight the common phosphoproteins and regulatory trends in the studied species. Moreover, the pollen phosphoproteome was compared with root hair phosphoproteome to pinpoint the common proteins taking part in their tip growth, which share the same cellular mechanisms.


2007 ◽  
Vol 97 (8) ◽  
pp. 892-899 ◽  
Author(s):  
Khalid Amari ◽  
Lorenzo Burgos ◽  
Vicente Pallas ◽  
María Amelia Sanchez-Pina

The route of infection and the pattern of distribution of Prunus necrotic ringspot virus (PNRSV) in apricot pollen were studied. PNRSV was detected both within and on the surface of infected pollen grains. The virus invaded pollen during its early developmental stages, being detected in pollen mother cells. It was distributed uniformly within the cytoplasm of uni- and bicellular pollen grains and infected the generative cell. In mature pollen grains, characterized by their triangular shape, the virus was located mainly at the apertures, suggesting that PNRSV distribution follows the same pattern as the cellular components required for pollen tube germination and cell wall tube synthesis. PNRSV also was localized inside pollen tubes, especially in the growth zone. In vitro experiments demonstrated that infection with PNRSV decreases the germination percentage of pollen grains by more than half and delays the growth of pollen tubes by ≈24 h. However, although PNRSV infection affected apricot pollen grain performance during germination, the presence of the virus did not completely prevent fertilization, because the infected apricot pollen tubes, once germinated, were able to reach the apricot embryo sacs, which, in the climatic conditions of southeastern Spain, mature later than in other climates. Thus, infected pollen still could play an important role in the vertical transmission of PNRSV in apricot.


Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2398
Author(s):  
Lenka Steinbachová ◽  
Jaroslav Matoušek ◽  
Gerhard Steger ◽  
Helena Matoušková ◽  
Sebastjan Radišek ◽  
...  

Viroids are small, non-coding, parasitic RNAs that promote developmental distortions in sensitive plants. We analyzed pollen of Nicotiana benthamiana after infection and/or ectopic transformation with cDNAs of citrus bark cracking viroid (CBCVd), apple fruit crinkle viroid (AFCVd) and potato spindle tuber viroid (PSTVd) variant AS1. These viroids were seed non-transmissible in N. benthamiana. All viroids propagated to high levels in immature anthers similar to leaves, while their levels were drastically reduced by approximately 3.6 × 103, 800 and 59 times in mature pollen of CBCVd, AFCVd and PSTVd infected N. benthamiana, respectively, in comparison to leaves. These results suggest similar elimination processes during male gametophyte development as in the Nicotiana tabacum we presented in our previous study. Mature pollen of N. benthamiana showed no apparent defects in infected plants although all three viroids induced strong pathological symptoms on leaves. While Nicotiana species have naturally bicellular mature pollen, we noted a rare occurrence of mature pollen with three nuclei in CBCVd-infected N. benthamiana. Changes in the expression of ribosomal marker proteins in AFCVd-infected pollen were detected, suggesting some changes in pollen metabolism. N. benthamiana transformed with 35S-driven viroid cDNAs showed strong symptoms including defects in pollen development. A large number of aborted pollen (34% and 62%) and a slight increase of young pollen grains (8% and 15%) were found in mature pollen of AFCVd and CBCVd transformants, respectively, in comparison to control plants (3.9% aborted pollen and 0.3% young pollen). Moreover, pollen grains with malformed nuclei or trinuclear pollen were found in CBCVd-transformed plants. Our results suggest that “forcing” overexpression of seed non-transmissible viroid led to strong pollen pathogenesis. Viroid adaptation to pollen metabolism can be assumed as an important factor for viroid transmissibility through pollen and seeds.


2017 ◽  
pp. 43 ◽  
Author(s):  
Silvia Espinosa-Matías ◽  
Sergio Zamudio ◽  
Judith Márquez-Guzmán

In order to gain greater knowledge about the embryology of the genus Pinguicula (Lentibulariaceae), a study of the development of male structures was conducted for a representative species of each subgenus. Embryological features concerning the development of the anther wall, microsporogenesis, microgametogenesis and pollen grains are described for the three species. These were generally consistent between them, and this evidence strongly supports the hypothesis that it is a monophyletic group. It does not support the division of the genus Pinguicula into three subgenera: Isoloba, Pinguicula and Temnoceras proposed by Casper (1966).


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