Pollen Growth Research Articles

Effect of sodium chloride, PGDO and Arabic gum in pollen liquid diluent on suspensibility of kiwi pollen

This study was conducted to develop the pollen liquid diluent suitable for the artificial pollination of kiwi. The pollen of ‘Matua’ kiwi was collected at 1 day before flowering. Five concentrations of sodium chloride (0, 50, 150, 250, and 350 mg․L -1 ), four concentrations of poly (glycolide-co-p-dioxanone) (0, 7, 14, and 21 mg․L -1 ), and four concentrations of arabic gum (0, 150, 350, and 550 mg․L -1 ) were tested on an absent condition of each component in the pollen liquid diluent. Twenty mg of pollen was distributed in beakers containing 10 mL of the pollen liquid diluent. Suspensibility of the pollen liquid diluent was measured by the sensory evaluation and particle size analyzer. The addition of sodium chloride in pollen liquid diluent was effectible for the suspensibility improvement and the promotion of pollen growth in kiwi pollen. The kiwi pollen in pollen liquid diluent could be suspended without damage in pollen germination at low concentration of poly (glycolide-co-p-dioxanone) (PGDO), which has been known as a safe surfactant. The addition of Arabic gum would be highly advantageous to the stabilization of the pollen liquid diluent without any contamination for pollen growth. Kiwi fruits were set and grown well by the artificial pollination using the pollen liquid diluent. Therefore, the use of the pollen liquid diluent in the artificial pollination of kiwi fruit should be an effective practice.

Floral phenology, secondary pollen presentation and pollination mechanism in Inula racemosa (Angiosperms: Asteraceae)

Inula racemosa Hook. f. is protandrous, discharges pollen grains inside the anther tube and presents pollen secondarily onto the sweeping hairs of the style. The style and stigmatic branches present the yellow clumped pollen grains for pollination. This study describes floral functional morphology and phenology, anther dehiscence and pollen presentation, growth and behaviour of style during anthesis and pollination mechanism of I. racemosa. The species is entomophilous and is characterized by a highly asynchronous sexual phase. A large degree of asynchrony from floret to floret in a capitulum, and capitulum to capitulum in a plant, keeps the pollen dispersed for a longer duration. Two insect families were represented in the pollinator survey: Hymenoptera and Diptera. A significant correlation was observed between the number of capitula visited per bout and foraging time. We discuss morphological features of the ?owers which may enhance the pollen removal rate per bee visit and consequently cause a high visitation and pollination rate.

Preparing for explosion: Pollen tubes are capacitated by the pistil.

Pollen tubes transport two immotile sperm cells in their cytoplasm during growth through the pistil, delivering one to the egg cell to form the zygote and one to the central cell to create the endosperm. Pollen tubes grow through the pistil’s complex extracellular environment and target ovules by following a gradient of small protein attractants, which are secreted by two specialized synergid cells within the ovule. This image shows Arabidopsis thaliana pollen tubes growing in vitro, and illustrates how pollen tubes gain the capacity to locate and enter ovules only after interaction with the pistil tissue. When pollen grains expressing red fluorescent protein (bottom) are placed directly on media in vitro, they exhibit random growth and are unable to target ovules (shown in white; middle). In contrast, when pollen expressing green fluorescent protein (top) is grown through an explant of stigma and style, pollen tubes grow more rapidly and efficiently target and enter ovules. Pollen transcriptional programs are rapidly induced during growth through the pistil, which prepares the pollen tube for interaction with the synergid cells. The molecular components that allow perception of the chemoattractants, which are similarly transcriptionally regulated, are beginning to be identified. Pollen growth in the pistil initiates pollen tube differentiation, maximizing the capacity of pollen to deliver sperm.

Identification of differentially accumulating pistil proteins associated with self‐incompatibility of non‐heading Chinese cabbage

Non-heading Chinese cabbage (Brassica campestris L. ssp. chinensis Makino), an important vegetable crop in China, exhibits a typical sporophytic self-incompatibility (SI) system. To better understand the mechanism of SI response and identify potential candidate proteins involved in the SI system of this vegetable crop, the proteomic approach was taken to identify differential accumulating pistil proteins. Pistils were collected at 0 h and 2 h after self-pollination at anthesis in self-incompatible and compatible lines of non-heading Chinese cabbage, and total proteins were extracted and separated by two-dimensional gel electrophoresis (2-DE). A total of 25 protein spots that displayed differential abundance were identified by matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI-TOF/TOF MS) and peptide mass fingerprinting (PMF). Among them, 22 protein spots were confidently established. The mRNA levels of the corresponding genes were detected by quantitative RT-PCR. The 22 identified protein spots are involved in energy metabolism (four), protein biosynthesis (three), photosynthesis (six), stress response and defence (five), and protein degradation (four). Among these potential candidate proteins, UDP-sugar pyrophosphorylase could be involved in sucrose degradation to influence pollen germination and growth. Glutathione S-transferases could be involved in pollen maturation, and affect pollen fertility. Senescence-associated cysteine protease, which is related to programmed cell death, could be mainly related to self pollen recognition of non-heading Chinese cabbage. The study will contribute to further investigations of molecular mechanism of sporophytic SI in Brassicaceae.

Regulation of Pollen Tube Growth by Transglutaminase.

In pollen tubes, cytoskeleton proteins are involved in many aspects of pollen germination and growth, from the transport of sperm cells to the asymmetrical distribution of organelles to the deposition of cell wall material. These activities are based on the dynamics of the cytoskeleton. Changes to both actin filaments and microtubules are triggered by specific proteins, resulting in different organization levels suitable for the different functions of the cytoskeleton. Transglutaminases are enzymes ubiquitous in all plant organs and cell compartments. They catalyze the post-translational conjugation of polyamines to different protein targets, such as the cytoskeleton. Transglutaminases are suggested to have a general role in the interaction between pollen tubes and the extracellular matrix during fertilization and a specific role during the self-incompatibility response. In such processes, the activity of transglutaminases is enhanced, leading to the formation of cross-linked products (including aggregates of tubulin and actin). Consequently, transglutaminases are suggested to act as regulators of cytoskeleton dynamics. The distribution of transglutaminases in pollen tubes is affected by both membrane dynamics and the cytoskeleton. Transglutaminases are also secreted in the extracellular matrix, where they may take part in the assembly and/or strengthening of the pollen tube cell wall.

Influence of Boric Acid and Sucrose on the Germination and Growth of Areca Pollen

This study investigates the effect of boric acid and sucrose on the germination and growth of Areca catechu L (areca palm). Using areca pollen from Hainan, China, this study determines the influence of culture media with different concentrations of boric acid and sucrose on the germination and growth of areca pollen. Results show that the germination and growth of the pollen tube growth are highest under a boric acid concentration of 0.4 g/L to 0.6 g/L. The germination rate of areca pollen is highest in solid medium with a sucrose concentration of 40 g/L. The optimum culture medium for developing areca pollen comprises 5 g/L agar, 0.4 g/L to 0.6 g/L boric acid, 40 g/L sucrose, and water. Furthermore, areca pollen grows most rapidly approximately 1.5 h after in vitro cultivation at normal temperature, and growth stabilizes at approximately 3 h. The principle that governs the development of areca pollen is also discussed.

Early F-actin disorganization may be signaling vacuole disruption in incompatible pollen tubes of Nicotiana alata

Self-incompatibility (SI) systems appeared early in plant evolution as an effective mechanism to promote outcrossing and avoid inbreeding depression. These systems prevent self-fertilization by the recognition and rejection of self-pollen and pollen from closely related individuals. The most widespread SI system is based on the action of a pistil ribonuclease, the S-RNase, which recognizes and rejects incompatible pollen. S-RNases are endocyted by pollen tubes and stored into vacuoles. By a mechanism that is still unknown, these vacuoles are selectively disrupted in incompatible pollen, releasing S-RNases into the cytoplasm and allowing degradation of pollen RNA. Recently, we have studied the timing of in vivo alterations of pollen F-actin cytoskeleton after incompatible pollinations. Besides being essential for pollen growth, F-actin cytoskeleton is a very dynamic cellular component. Changes in F-actin organization are known to be capable of transducing signaling events in many cellular processes. Early after pollination, F-actin showed a progressive disorganization in incompatible pollen tubes. However by the time the F-actin was almost completely disrupted, the large majority of vacuolar compartments were still intact. These results indicate that in incompatible pollen tubes F-actin disorganization precedes vacuolar disruption. They also suggest that F-actin may act as an early transducer of signals triggering the rejection of incompatible pollen.

A novel method for efficient in vitro germination and tube growth of Arabidopsis thaliana pollen

In addition to its importance in studies of plant reproduction and fertility, pollen is as widely employed as a model system of cell growth and development. This work demands robust, reproducible methods to induce pollen germination and morphologically normal growth of pollen tubes in vitro. Despite numerous advantages of Arabidopsis thaliana as a model plant, such experiments on pollen germination and pollen tube growth have often proved challenging. Our new method employs a physical cellulosic membrane, overlying an agarose substrate. By modulating the substrate composition, we provide important insights into the mechanisms promoting pollen growth both in vitro and in vivo. This effective new technical approach to A. thaliana pollen germination and tube growth results in swift, consistent and unprecedented levels of germination to over 90%. It can also promote rapid growth of long, morphologically normal pollen tubes. This technical development demonstrates that exogenous spermidine and a cellulosic substrate are key factors in stimulating germination. It has potential to greatly assist the study of reproduction in A. thaliana and its closest relatives, not only for the study of germination levels and pollen tube growth dynamics by microscopy, but also for biochemical and molecular analysis of germinating pollen.

Hybridization betweenPyrola grandifloraandPyrola minorin West Greenland: a tension zone maintained by clonality

Interspecific hybridization may lead to novel hybrid lineages and transfer of genetic material, possibly enabling species to expand into new habitats. Alternatively, hybrids may be inviable or sterile, constraining movement of parental species and genes into each others range. Pyrola minor (L.) and Pyrola grandiflora (Rad.) hybridize on Disko Island in Greenland. A recent study found most hybrids to be F1plants produced by P. minor mothers. Here, we test if later generation hybrids are indeed absent in a larger sample, using morphological and molecular markers. We further test if unidirectional hybridization is due to reproductive barriers. Intermediate plants were all F1hybrids from P. minor mother plants. Our analyses indicate that hybrids originated from few hybridization events and have been maintained by clonal reproduction since then. Barriers to pollen flow between the species result from a combination of few pollinators, different flower morphology and phenology, high proportions of abnormal pollen in hybrids, and reduced pollen tube growth of heterospecific and hybrid pollen. In general, pollen from P. grandiflora grew better than pollen from P. minor, which may explain the unidirectional hybridization. Hybridization between P. grandiflora and P. minor therefore seems to operate like a tension zone in which F1hybrids are maintained by clonal propagation.

Hygroscopic growth and cloud activation of pollen: a laboratory and modelling study

AbstractThis study investigates the hygroscopic growth of pollen. An electrodynamic balance was used to measure the water uptake on pollen and an environmental scanning electron microscope was used to visualize the response of the pollen to subsaturated humidities. Pollen was found to be moderately hygroscopic and its surface wettable at high humidities. The hygroscopicity data were parameterized using κ‐Köhler theory and used in a rising parcel cloud model to investigate the effect of pollen on sulfate activation. Our data suggest that extreme pollen concentrations (>1000 m−3) may interfere with the activation of the background sulphate aerosol mode in pristine environments. Copyright © 2012 Royal Meteorological Society

Prezygotic interspecific hybridization barriers between kenaf (Hibiscus cannabinus L.) and four wild relatives

AbstractUse of interspecific hybridization in genetic improvement of kenaf (Hibiscus cannabinus), a multipurpose crop, is limited by low cross‐compatibility. Previous hybridization studies suggest that part of incompatibility barrier is prezygotic. Pollen germination, stigma receptivity and growth of alien pollen on kenaf pistil were studied using wild relatives of kenaf. Four wild and semi‐domesticated species, H. surattensis, H. acetosella, H. radiatus and H. vitifolius, were used as pollen donors in the present experiment. H. radiatus exhibited highest pollen germination (65.89%) on H. cannabinus stigma. For closely related species (H. surattensis, H. acetosella, H. radiatus), stylar incompatibility was noticed, while for distantly related species H. vitifolius, the incompatibility was stigmatic. Number of pollen tubes entering ovule of H. cannabinus pistil was higher for H. radiatus (1.30). Alien pollen growth and penetration of pollen tube through ovule were higher in species sharing same genome of H. cannabinus. High callose deposition was observed in incompatible crosses, suggesting a general mechanism for prezygotic incompatibility in Hibiscus section Furcaria. Callose deposition in incompatible crosses increased with time.

Isohericenone, a new cytotoxic isoindolinone alkaloid from Hericium erinaceum

In our continuing search for structurally interesting and cytotoxic metabolites from Korean wild mushrooms,1–5 we have collected scores of Korean mushroom species annually and evaluated their MeOH extracts for their antitumor activity in our screening test. Among the collected wild mushrooms, the extract of Hericium erinaceum showed significant cytotoxicity against A549, SK-OV-3, SK-MEL-2 and HCT15 cell lines using a sulforhodamine B (SRB) bioassay. This mushroom H. erinaceum (Yamabushitake in Japanese) belonging to the family Hericiaceae is widely known as edible mushroom that grows on dead trunks of hard woods in Korea, Japan, China and Europe. This mushroom has been used as a medicine for the treatment of dyspepsia, gastric ulcer and enervation in traditional Chinese medicine for a long time.6 This medicinal mushroom is a rich source of unique metabolites. Chemical components of this mushroom have been reported to have hericenones A and B as cytotoxic constituents,7 hericenones C, D and E as stimulators of nerve growth factor synthesis,8 hericenone J as an endoplasmic reticulum stress-suppressive substance,9 hericerin as a pollen growth inhibitor10 and antitumor-active polysaccharides11 as the bioactive components. A bioassay-guided fractionation and chemical investigation of its MeOH extract resulted in the isolation of a new isoindolinone alkaloid named isohericenone (1), together with nine known compounds, namely isohericerin (2),6 erinacerin B (3),12 hericenone A (4),7 hericenone J (5),9 3,4-dihydro-5-methoxy-2methyl-2-(40-methyl-20-oxo-30-pentenyl)-9(7H)-oxo-2H-furo[3,4-h] benzopyran (6),13 erinacerin A (7),12 hericenone F (8),14 hericenone D (9)8 and hericenone E (10)8 (Figure 1). Here, we describe the isolation and structural elucidation of (1) as well as the cytotoxic activities of compounds 1–10. The half dried fruiting bodies of H. erinaceum (5.0 kg) were extracted with 80% aqueous MeOH twice at room temperature and then filtered. The filtrate was evaporated under vacuum to afford a MeOH extract (500 g), which was partitioned with hexane, CH2Cl2, EtOAc and n-BuOH subsequently with H2O, yielding hexane (63.3 g), CH2Cl2 (4.5 g), EtOAc (2.0 g) and n-BuOH fractions (17.5 g). Each fraction was evaluated for its cytotoxicity against A549, SK-OV-3, SKMEL-2 and HCT-15 cell lines using a SRB bioassay. We selected the hexane-soluble and CH2Cl2-soluble fractions for the current phytochemical investigation, because the CH2Cl2-soluble fraction was the most active and hexane-soluble fraction also had significant cytotoxicity against the tested tumor cell lines. The active hexane-soluble fraction (60 g) was separated on a silica gel column with a gradient solvent system of hexane-EtOAc (50 : 1–1 : 1) to give five fractions (H1–H5). Fraction H1 (11 g) was separated on a RP-C18 silica gel column using a gradient solvent of increasing MeOH in H2O from 10 to 100% to give three subfractions (H11–H13). Fraction H13 (5 g) was separated twice on a RP-C18 silica gel column with a gradient solvent system of MeOH-H2O (2 : 3–7 : 3) and then purified by RPC18 preparative HPLC (Econosil RP-18 10m column (Alltech, Nicholasville, KY, USA), 250 10 mm2) using a solvent of MeOHH2O (1 : 1) to yield compound (5) (9 mg). Fraction H2 (12 g) was subjected to repeated RP-C18 silica gel column separation using a gradient solvent system of MeOH-H2O (1 : 1–7 : 3) and then purified by RP-C18 preparative HPLC (60% MeOH) to afford compound (6) (4 mg). Fraction H5 (10 g) was separated on a RP-C18 silica gel column using a gradient solvent of increasing MeOH in H2O from 10 to 100% to give three subfractions (H51-H53). Fraction H51 (1 g) was isolated using repeated RP-C18 silica gel column separation with a gradient solvent system of MeOH-H2O (2 : 3–7 : 3) and then purified by RP-C18 preparative HPLC (60% MeOH) to give compound (9) (38 mg). Fraction H53 (1 g) was subjected to repeated RP-C18 silica gel column separation using a gradient solvent system of MeOH-H2O (1 : 1–7 : 3) and then purified by RP-C18 preparative HPLC (50% MeOH) to afford compound (8) (36 mg). The most active CH2Cl2soluble fraction (4 g) was separated on a silica gel column with a gradient solvent system of CH2Cl2-MeOH (50 : 1–1 : 1) to yield five fractions (C1–C5). Fraction C2 (1 g) was separated on a RP-C18 silica gel column using a gradient solvent of increasing MeOH in H2O from

Proteomic analysis of rice anthers under salt stress

Salinity is a major factor that limits rice production worldwide. Rice is considered generally to be sensitive to salt stress during the reproductive stage. To determine the molecular mechanisms of salt tolerance at the reproductive stage, anther proteomic patterns for two contrasting rice genotypes IR64 (salt sensitive) and Cheriviruppu (salt tolerant) under salt stress were compared. Plants were grown in a greenhouse and salt stress (100mM NaCl) was imposed at the booting stage. Anther samples were collected from control and salt-treated plants at the anthesis stage. The Na(+)/K(+) ratio in IR64 anthers under salt stress was >1.7 times greater than that under control conditions, whereas no significant change was observed in Cheriviruppu. We also observed an 83% reduction in IR64 pollen viability, whereas this reduction was only 23% in Cheriviruppu. Of 454 protein spots detected reproducibly on two-dimensional electrophoresis gels, 38 showed significant changes in at least one genotype in response to stress. Using Mass spectrometry (MALDI TOF/TOF) analysis, we identified 18 protein spots that were involved in several processes that might increase plant adaptation to salt stress, such as carbohydrate/energy metabolism, anther wall remodelling and metabolism, and protein synthesis and assembly. Three isoforms of fructokinase-2 were upregulated only in Cheriviruppu under salt stress. This upregulation might result in increased starch content in pollen, which would support pollen growth and development under salt stress. The results also suggested that anther and pollen wall remodelling/metabolism proteins contribute to the tolerance of rice to salt stress.

Total Synthesis and Structural Revision of Hericerin

The total synthesis of hericerin, a pollen growth inhibitor from Hericium erinaceum, was achieved. We found that the reported structure of hericerin should be revised to be the carbonyl regioisomer.

미량요소 첨가가 자가불화합성 억제에 미치는 영향

Self-incompatibility (SI) system is a genetic barrier that prevents self-fertilization and promotes cross-pollination among different S genotypes. In many of these species, SI is controlled by a single genetic locus known as S locus, which prevents the fertilization by pollen with same locus. S RNases are the products of the S-locus expressed in the stylar tissue of Fuji Apple with gametophytic self-incompatibility system. This study investigated the various types of chemicals in order to select more effective inhibitors and activators. The effect on the inhibition of S RNase of Fuji apples was investigated in vitro. The result showed that the enzyme activity was reduced 24.3% by Iron(Ⅱ) Sulfate, significantly. In vitro studies of pollen growth tube showed that pollen tube growth had a higher germination rate (90%) in 10% Sucrose than in 2% sucrose extension medium. Data on the fruit set of apples treated with inhibitor and activator. Double application of A + (Apple Plus, ISTECH Co. Ltd.,)+Vitamin B6 had the highest central fruit set as 86.1%(Andong). One time application of A ++ Vitamin B1 in Yeongju obtained the highest central fruit set (91.9%).

Polarized cell growth in Arabidopsis requires endosomal recycling mediated by GBF1-related ARF exchange factors

Polarized tip growth is a fundamental cellular process in many eukaryotic organisms, mediating growth of neuronal axons and dendrites or fungal hyphae. In plants, pollen and root hairs are cellular model systems for analysing tip growth. Cell growth depends on membrane traffic. The regulation of this membrane traffic is largely unknown for tip-growing cells, in contrast to cells exhibiting intercalary growth. Here we show that in Arabidopsis, GBF1-related exchange factors for the ARF GTPases (ARF GEFs) GNOM and GNL2 play essential roles in polar tip growth of root hairs and pollen, respectively. When expressed from the same promoter, GNL2 (in contrast to the early-secretory ARF GEF GNL1) is able to replace GNOM in polar recycling of the auxin efflux regulator PIN1 from endosomes to the basal plasma membrane in non-tip growing cells. Thus, polar recycling facilitates polar tip growth, and GNL2 seems to have evolved to meet the specific requirement of fast-growing pollen in higher plants.

In vitro pollen germination in stone fruit tree of Rosaceae family

In the tone fruit trees including almond, apricot, plum, prune, sour cherry and sweet cherry, pollen performance includes pollen quantity produced in a flower and pollen quality consists of viability, longevity, morphological homogeneity, pollen germination and pollen tube growth rate which are very important component of fertilization and fruit setting. However, study of pollen traits is one of the most important approaches for growers and breeders. In this research, main pollen traits including germination and tube growth were investigated in some selected cultivars of Prunus species including P. dulcis, P. armeniaca, P. domestica, P. ceracus, P. salicina and P. avium. Pollen traits of 5 cultivars from each species were studied using the in vitro medium containing 15% sucrose, 1% agar 5 ppm H3BO3 (boric acid). Pollens were planted in the in vitro medium inside the Petri-dishes and incubated at the constant temperature of 24°C for 24 h and then, pollen germination and growth were protected by adding chloroform. Data analysis showed that in all of the studied traits significant differences were observed among six species and cultivars of each species. Key words: Almond, apricot, plum, prune, sour cherry, sweet cherry, Rosaceae, pollen viability, in vitro.

Functional compounds and antioxidant properties of dried green and red peppers

Eight fungicides namely Sumi-eight, Cupravit, Karatane, Topsin-M, Vitavax thiram, Beam, Benlate and Tecto at commercially recommended concentrations and at double concentrations were evaluated for their effects on pollen germination, tube growth and morphology of almond cultivar (Ferragness) in basic medium or control (100 mg L-1 boric acid, 15% sucrose and 1% agar) at 24°C in dark condition. Results showed that different treatments had significant effects on the germination, tube growth and morphology of pollen. All fungicides reduced the percentage of pollen germination, length of germ-tube elongation and morphological features of almond pollens. The negative effects of fungicides on pollen germination percentage and germ-tube elongation and view of pollen morphology were variable and dependent on type and material concentrations. The highest pollen germination (100%) for almond cultivar (Ferragness) was recorded in 100 mg L-1 boric acid, 15% sucrose and 1% agar medium (control). The lowest pollen germination percentage (0.0%) was found in 100 mg L-1 boric acid, 15% sucrose and 1% agar medium contain 2 g L-1Karatane. Key words: Almond, culture pollen, fungicide, germination.

The size and germinability of Scots pine pollen in different temperatures in vitro

The effect of genotype, the origin of genotype, and germination temperature on Scots pine pollen grain size, hydration rate, germinability, and tube growth was studied in vitro. The mean sizes of dry and germinated pollen grains varied among pollen genotypes in different ways, thus the hydration rate varied among genotypes. Pollen from Scots pine that originates in northern Finland hydrated more than pollen from a population in southern Finland. Germination temperature had no effect on the hydration rate. Germinability and tube growth rate of northern genotypes were higher at 20 °C than at 15 °C. Differences among southern genotypes were not significant. At 15 °C, the germinability and pollen tube growth rate of northern genotypes were lower than southern genotypes. At 20 °C, the differences were not significant. It appears that germination and growth of pollen from northern populations are enhanced at higher temperatures whereas pollen from southern populations is unaffected.

Identification of lily pollen 14-3-3 isoforms and their subcellular and time-dependent expression profile

14-3-3 proteins are major regulators in plant development and physiology including primary metabolism and signal transduction pathways, typically via a phosphorylation-dependent interaction with a target protein. Four full-length 14-3-3 isoforms were identified in pollen grains of Lilium longiflorum by screening of a cDNA library and RACE (rapid amplification of cDNA ends)-PCR. Mass spectrometry analysis of partially purified 14-3-3s confirmed the presence of the four isoforms but also indicated the presence of additional, less abundant 14-3-3 isoforms in lily pollen. Separation of partially purified 14-3-3 proteins by two-dimensional gel electrophoresis resulted in nine spots that mainly contained the four major 14-3-3 isoforms. In a first step to examine putative physiological roles of specific 14-3-3 isoforms, their subcellular expression profile during pollen germination and tube growth was monitored using a characterized set of antibodies against 14-3-3 proteins with distinct crossreactivity. The abundance profile of 14-3-3 proteins associated with the cytosol, endomembranes (tonoplast, endoplasmic reticulum, Golgi, mitochondria) and plasma membrane showed high spatial-temporal dynamics. This indicates different targets of 14-3-3 proteins at different organelles and time points during pollen germination and growth.