Abstract
Abstract In vitro culture of Lilium longiflorum pollen grains was carried out to determine the role of manganese in pollen germination and pollen tube growth. Pollen germination was adversely affected by the presence of manganese (>10 −8 M), whereas low concentrations (10 −12 –10 −10 M) stimulated the process. Manganese caused morphological anomalies during tube growth, characterized by irregular pollen tube thickening and swollen tips. The main effect was the anomalous cell wall formation at the tip, in which the presence of several organelles reduced the number of secretory vesicles. A loose network of fibrillar material and spherical aggregates, mostly in the tip region, was detected, and this material was progressively loosened into the surrounding medium. As a response to potential toxicity, the excess manganese was isolated in vacuoles, which formed an internal barrier against penetration of manganese to the tip area. Elevated manganese concentrations might affect plant reproduction, resulting in anomalies in gamete development. Consequently, the loss in genetic diversity and decreased fruit set ultimately lower yield.
Highlights
Pollen grains are found in the flower anthers, which are necessary for sexual reproduction in angiosperms
Pollen grains are considered to be extremely minuscule systems combining anatomical simplicity with rapid growth rate of the pollen tube (Sawidis, 2008; Sawidis & Reiss, 1995). e process of pollen tube growth and elongation serves as an excellent model for studying plant cellular morphogenesis at the single-cell level. is process can be influenced by many external factors, including various toxic substances. e ability of pollen tubes to grow in vitro makes them a practical model for real-time testing of the effect of heavy metals on the ultrastructural level
The pollen tube has been used as a well-suited model system for the evaluation of metal toxicity in plant cells (Gur & Topdemir, 2005; Sawidis et al, 2018). e effects of heavy metals on germinating pollen grain are one of the most interesting questions, and propagation experiments as well as studies of in vitro pollen germination in flowering plants are very useful for explaining any lack of plant fertility and the importance of reproduction for the continuity of species
Summary
Pollen grains are found in the flower anthers, which are necessary for sexual reproduction in angiosperms. E effects of heavy metals on germinating pollen grain are one of the most interesting questions, and propagation experiments as well as studies of in vitro pollen germination in flowering plants are very useful for explaining any lack of plant fertility and the importance of reproduction for the continuity of species. As a component of more than 35 different enzymes, manganese either stimulates or greatly affects various biochemical and physiological functions in plant metabolism (Andresen et al, 2018; Diedrick, 2010). It is involved in aspects of plant tip growth, such as pollen tube growth and root hair cell elongation (Somerville & Nicol, 2002). Elevated levels of manganese in pollen have been reported in cases of industrial, urban, and rural sites, with concentrations ranging from 21 to 110 ppm (Kamran, 2000)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
