Implications of ionizing radiation on pollen performance in comparison with diverse models of polar cell growth

Abstract

Research concerning the effects of ionizing radiation (IR) on plant systems is essential for numerous aspects of human society, as for instance, in terms of agriculture and plant breeding, but additionally for elucidating consequences of radioactive contamination of the ecosphere. This comprehensive survey analyses effects of x‐ and γ‐irradiation on male gametophytes comprising primarily in vitro but also in vivo data of diverse plant species. The IR‐dose range for pollen performance was compiled and 50% inhibition doses (ID50) for germination and tube growth were comparatively related to physiological characteristics of the microgametophyte. Factors influencing IR‐susceptibility of mature pollen and polarized tube growth were evaluated, such as dose‐rate, environmental conditions, or species‐related variations. In addition, all available reports suggesting bio‐positive IR‐effects particularly on pollen performance were examined. Most importantly, for the first time influences of IR specifically on diverse phylogenetic models of polar cell growth were comparatively analysed, and thus demonstrated that the gametophytic system of pollen is extremely resistant to IR, more than plant sporophytes and especially much more than comparable animal cells. Beyond that, this study develops hypotheses regarding a molecular basis for the extreme IR‐resistance of the plant microgametophyte and highlights its unique rank among organismal systems.

Effects of Environmental Stress Factors on the Actin Cytoskeleton of Fungi and Plants: Ionizing Radiation and ROS

“…Concerning collective plant microgametophytes the mean value of 50% inhibition doses (ID 50 ) for gammaradiation amounts to significantly more than 1000 Gy. Whereas the mean ID 50 of plant sporophytes is substantially below 100 Gy [15]. Also the IR-tolerance of fungal hyphae is considerably higher than that of plant sporophytes.…”

“…In the latter case, polarized growing hyphae of filamentous fungi generate large mycelial structures and sporocarps (fruitbodies). Members of the multifaceted taxon fungi thrive in diverse habitats, yet their tolerance of ionizing radiation is in general very high, which is similar to the extreme IR-resistance of pollen performance [15]. Concerning collective plant microgametophytes the mean value of 50% inhibition doses (ID 50 ) for gammaradiation amounts to significantly more than 1000 Gy.…”

“…Also the IR-tolerance of fungal hyphae is considerably higher than that of plant sporophytes. When comparing diverse species of fungi, the ID 50 ranges approximately between 500 and 5000 Gy [15].…”

“…Most importantly, this scientific issue is particularly interesting, because some plant cells (pollen) and fungal hyphae are extremely tolerant of acute high dose ionizing radiation. Generally their lethal doses are far beyond those of animal or human cells [15]. Deeper analysis of the molecular basis for these differences between IR-susceptibility of plant gametophytes, plant sporophytes, fungi, and animals can provide new concepts and approaches for improvement of human cancer treatment, for radiation protection, and eventually for dealing with contaminations of the biosphere.…”

Assessment of The Effect of Gamma Ray Treatments on Pollen Behavior in Cyclamen

“…Therefore, the effects of irradiation doses on in vitro pollen tube length may differ among plant species in a dosedependent manner. Additionally, Stephan (2021) indicated that ionization radiation affects pollen tube growth and nuclear function. Ionization radiation causes dramatic impairment of the genome entity, but its effects on polar growth are minor.…”