Pollen tubes

Xiao, C.-M. Mascarenhas, J.P. (1985). High temperature-induced thermotolerance in pollen tubes of Tradescantia and heat-shock protein. Plant Physiology, 78, 887-9. 

Procedure Pollen develops on the nutrition medium, forming pollen tube (Fig. 3). The nutrient medium for pollen was 10% sucrose solution and tested compounds were also dissolved in 10% sucrose. The pollen develops till the formation of pollen tube that lasts from 2-3 h (fresh collected and one week stored pollen) to 24 h (stored > 1 week, but < 1.5-2 months). All experiments were done at room temperature 20-22 °C. The growth occurred in the solution studied (0.05 ml = 1 drop) on the slides (object glasses) put on wet paper in Petri dishes. Five ml of water was added to the bottom of every dish and 4-5 dishes with the slides were used per treatment. Using light microscope, we determined the microspores germination (%) 2-24 h after moistening. The number of developed pollen tubes was counted. 

Experiment 1. Effects of volatile allelochemicals on development of pollen tubes. In this experiment, volatile and liquid excretions from plants with pesticidic properties were tested (Table 3). The development of pollen tubes depend on the concentration and the distance from the object glass with microspores moistened with nutrient medium vapors of lavender oil (active matter) depress the process as well as red pepper, but garlic not. Water extracts of garlic were more effective. 

Excretion Quantity of pollens with pollen tubes... 

Fig. 11 Fluorescence of pollen grain from Hippeastrum hybridum stained with azulene 10-5 (left, bright lightening of cell wall and less intensive emitted nucleus in centre) or pollen tube stained with colchicine 1CT7 M (right, lightening parts of pollen tube may be tubulinbinding sites).

Blue colour ring concentrated on plasmalemma of pollen (A). Arrows on B (lower part) shows a difference in the colour between cellular surface (blue color) and apperture for the output of pollen tube (red colour). Pistil excreted blue colour product, which covers the red coloured surface of pistil. The cholinesterase activity in plants is considered as sensitive test to study the allelopathic activity (Roshchina and Roshchina 1993 Roshchina,1999 2001a). 

The staining of germinated pollen of Hippeastrum hybridum with colchicine demonstrates green-yellow emission of microtubules (better vision in black-white image) around nuclei of pollen grain (threads at the division of the nucleus) and spermium on the tip of the pollen tube, where spermium moves, as well as in some bridge sites of the tube (Fig. 10). The similar fluorescent allelochemicals may be also used as fluorescent dyes at the cellular diagnostics (Roshchina, 2005 b). 

Fig. 10 The LSCM images of Hippeastrum hybridum pollen tube stained with colchicine 10" 7 M. The laser excitation wavelength 458 nm. 1. The bright emission is observed in nucleus of vegetative cell of pollen and in the spermium located in the tip of the tube 2. Spermium in the tip of pollen tube. The microtubules contained of tubulin are seen. 

Victoria Roshchina s group elucidated and identified the mechanisms of pollen allelochemicals. At this stage, it remains to be tested whether terpenoid allelochemicals require pollen rehydration and exudation, which would make them likely to occur in trinucleate pollen and then function by binding on plasmalemma and perhaps are then transformed in a growing heterospecific pollen tube into free radicals that affect membranes or key enzymes. 

Rosen WG, Gawlik SR, Dashek WV, Siegesmund KA. Fine structure and cytochemistry of Lilium pollen tubes. Am JBot 1964 51 61-67. 

Reynolds JD, DashekWV. Cytochemical analysis ofcallose distribution in Lilium longiflorum pollen tubes. Ann Bot 1976 40 409-416. 

A protocol for the light microscope radioautography of Lilium longiflorum pollen tubes labeled with [14C]-proline follows. This protocol, which does not require tissue embedding in paraffin or Paraplast, can be modified for paraffin-embedded tissues see Chapter 2). Thus, by employment of the protocol, together with the preceding introductory information in this chapter, one should be able to derive a protocol applicable to the cells or tissue in question. The performance of the protocol requires approval of an institution s Radiation Safety Officer. An inventory of incoming radionuclides, their presence in secondary containers, and their waste must be carefully recorded. The waste must be further broken down into solid waste, liquid waste, and animal carcasses to aid in its proper disposal. 

Dashek WV, Rosen WG. Electron microscopical localization of chemical components in the growth zone of Lilium pollen tubes. Protoplasma 1966 61 191-204. 

Dashek WV, Mills RW. Azetidine-2-carboxylic acid and lily pollen tube elongation. Ann Bot 1980 45 1-12. 

Doris FP, Steer MW. Effects of fixatives and permeabilisation buffers on pollen tubes implications for localisation of actin microfilaments using phalloidin staining, Protoplasma, 1996 195 25-36. 

The pollen tube walls contain callose-like polysaccharides that absorb aniline blue. That is why this method is very useful to detect pollen tube elongation and to understand how the tube penetrates the inside of the pistil tissue. The pollen tubes grow from the surface ofthe stigma through... 

In many plant species compatible pollen tubes grow directly down inside the style as a bundle of long smooth tubes with bright callose plugs. Only in female sterile plants of Oenothera mut. brevistylis was branching of pollen tubes found in the style and ovary (7). 

Particular Observations of Pollen Tube Growth and Its Interaction with Ovules... 

Another problem is the direction of pollen tube growth, which should be considered as tropism, related to attraction by the fertile ovules. Many observations of pollen tubes in the fluorescence microscope supported this suggestion—pollen tubes pass by the sterile ovules and grow in the direction of the fertile ones. The number of ovules penetrated by a pollen tube is correlated with the number of developing seeds, which supports the hypothesis about interaction (attraction) between the ovule and pollen tube (1,2,5). 

Williams EG, Knox RB. Quantitative analysis of pollen tube growth in Lycopersicon peruvianum. JPalynol 1982 18 65-74. 

Wilms HJ. Branching of pollen tubes in spinach, in Fertilization in Higher Plants (Lins kens HF, ed.), North-Holland Publishing, Amsterdam, 1974, pp. 155-160. 

Sniezko R. Pollen tube branching in the ovary of five species of Oenothera. Acta SocBotPol 1996 65 111-116. 

Sniezko R, Sadaj A. Pattern of pollen tube growth in the Capsel la bursa pastiris and Sisymbrium loeselii (Brassicaceae). VIII Conference of Plant Embryologists, 16-18 September, Gdansk, Poland, 1997. 

Dark-Field Microscopy and Its Application to Pollen Tube Culture... 

Dark-Field Microscopy Application of Dark-Field Microscopy to Pollen Tube Culture The Protocol... 

General Comments for Pollen Tube Culture References... 

APPLICATION OF DARK-FIELD MICROSCOPY TO POLLEN TUBE CULTURE... 

Make the medium shown in Table 1 (200 mL for 10 Petri dishes). For the growth of pollen tubes in vitro, calcium and borate are generally required. Sucrose is also added to the medium, mainly for the purpose to adjust the osmotic pressure it is unclear whether the external sucrose plays a role... 

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