Radiation Effects. Toxicity of Plants after

irradiation.Dmitri Popov MD (Russia), PhD (Russia-Canada)Advanced Medical Technology and Systems Inc.

intervaccine@gmail.com

Radiation Effects. Toxicity of Plants after irradiation.• DOI: 10.13140/RG.2.1.3185.6400

Radiation Effects. Toxicity of Plants after irradiation.• Programmed cell death (PCD) occurs in animals and plants under

various stresses and during development. Recently, vacuolar processing enzyme (VPE) was identified as an executioner of plant PCD.• “A cellular suicide strategy of plants: vacuole-mediated cell death”• Apoptosis 2006; 11: 905–911 C 2006 Springer Science + Business

Media, LLC. Manufactured in The United States. DOI: 10.1007/s10495-006-6601-1. N. Hatsugai et al.

Radiation Effects. Toxicity of Plants after irradiation.• Recently, vacuolar processing enzyme (VPE) was identified as an

executioner of plant PCD. VPE is a cysteine protease that cleaves a peptide bond at the C-terminal side of asparagine and aspartic acid.• “A cellular suicide strategy of plants: vacuole-mediated cell death”• Apoptosis 2006; 11: 905–911 C 2006 Springer Science + Business

Media, LLC. Manufactured in The United States. DOI: 10.1007/s10495-006-6601-1. N. Hatsugai et al.

Radiation Effects. Toxicity of Plants after irradiation.• Programmed cell death (PCD) is an active, genetically controlled• process leading to selective elimination of unwanted or damaged cells

in eukaryotes. PCD is essential for growth and development of multicellular organisms as well as for proper response to environment (Gechev et al., 2006; Lam, 2004).

Radiation Effects. Toxicity of Plants after irradiation.• Plant PCD is associated with a number of developmental processes

including embryo formation, degeneration of the aleurone layer during monocot seed germination, differentiation of tracheary elements in water-conducting xylem tissues, formation of root aerenchyma and epidermal trichomes, anther tapetum degeneration, floral organ abscission, pollen self-incompatibility, remodeling of some types of leaf shape, and leaf senescence. (Gechev et al., 2006; Thomas and Franklin-Tong, 2004).• Programmed Cell Death in Plants: New Insights into Redox Regulation• and the Role of Hydrogen Peroxide• Ilya Gadjev,1,* Julie M. Stone,† and Tsanko S. Gechev*

Radiation Effects. Toxicity of Plants after irradiation.• Hydrogen peroxide (H2O2) and other reactive oxygen species (ROS)

have become recognized to be key modulators of PCD of as well as many other biological processes such as growth, development, and stress adaptation (Gechev et al., 2006).

Radiation Effects. Toxicity of Plants after irradiation.• Although specific ROS receptors/sensors remain largely elusive,

downstream components of H2O2 and ROS signal transduction networks controlling plant PCD have been identified, including protein kinases, protein phosphatases, and transcription factors. The majority of these are restricted to plants, with only a few genes having close homologues in animals. (Gechev et al., 2006).

Radiation Effects. Toxicity of Plants after irradiation.• Hydrogen peroxide is produced in all cellular compartments as a

result of reactions of energy transfer, electron leakage from saturated electron transport chains, and the activities of various oxidases and peroxidases (Apel and Hirt, 2004).

Radiation Effects. Toxicity of Plants after irradiation.• Programmed cell death (PCD) is a process by which cells in many

organisms die. The basic morphological and biochemical features of PCD are conserved between the animal and plant kingdoms. Cysteine proteases have emerged as key enzymes in the regulation of animal PCD.

Radiation Effects. Toxicity of Plants after irradiation.• The discovery that cell death is a tightly regulated (programmed) process

has stirred a great deal of interest in its mechanisms. Studies of animal systems have shown that the execution of programmed cell death (PCD) or apoptosis is controlled by a multistep signaling pathway (McConkey and Orrenius, 1994; Stewart, 1994).• In plants, PCD has been implicated in xylogenesis (Fukuda, 1996; Groover et al., 1997), in some forms of senescence, and in the hypersensitive response to pathogens and environmental stresses (Greenberg, 1996; Mittler and Lam, 1996; Lamb and Dixon, 1997).

Radiation Effects. Toxicity of Plants after irradiation.• Although a detailed understanding of how plant cells die is still largely

unknown, recent studies have shown that the apoptotic pathways of the animal and plant kingdoms are morphologically and biochemically similar (Greenberg, 1996; Levine et al., 1996; Wang et al., 1996).

Radiation Effects. Toxicity of Plants after irradiation.• Specifically, the morphological hallmarks of apoptosis include

cytoplasmic shrinkage, nuclear condensation, and membrane blebbing (Earnshaw, 1995; Martins and Earnshaw, 1997); the biochemical events involve calcium influx, exposure of phosphatidylserine and activation of specific proteases and DNA

fragmentation, first to large 50-kb fragments and then to nucleosomal ladders (McConkey and Orrenius, 1994; Stewart, 1994; Wang et al., 1996; O’Brien et al., 1998).

Radiation Effects. Toxicity of Plants after irradiation.• The Involvement of Cysteine Proteases and Protease Inhibitor Genes in the

Regulation of Programmed Cell Death in Plants. • The Plant Cell, Vol. 11, 431–443, March 1999, www.plantcell.org © 1999

American Society of Plant Physiologists.

Radiation Effects. Toxicity of Plants after irradiation.• VPE processing system mediates a cellular suicide strategy in plants. In animals, dying cells are

packaged into apoptotic bodies• and then engulfed by phagocytes. In contrast, because plants do not have phagocytes and the

cells are surrounded by rigid cell walls, plant• cells must degrade their materials by themselves. VPE, which has caspase-1-like activity, is

accumulated after perception of death signals such• as pathogen infection. VPE is involved in activation of the target proteins to provoke

disintegration of the vacuolar membranes. Consequently,• the vacuolar hydrolytic enzymes leave the vacuole for the cytosol and degrade cellular

components. Plants have evolved a death strategy that• is mediated by the VPE processing system, which is not seen in animals.                  A cellular 

suicide strategy of plants: vacuole-mediated cell death.                  N. Hatsugai et al. DOI: 10.1007/s10495-006-6601-1

Radiation Effects. Toxicity of Plants after irradiation.• The genome of an organism is under constant attack from endogenous and exogenous

DNA damaging factors, such as reactive radicals, radiation, and genotoxins. Therefore, DNA damage response systems to sense DNA damage, arrest cell cycle, repair DNA lesions, and/or induce programmed cell death are crucial for maintenance of genomic integrity and survival of the organism. Genome sequences revealed that, although plants possess many of the DNA damage response factors that are present in the animal systems, they are missing some of the important regulators, such as the p53 tumor suppressor. These observations suggest differences in the DNA damage response mechanisms between plants and animals. In this review the DNA damage responses in plants and animals are compared and contrasted. In addition, the function of SUPPRESSOR OF GAMMA RESPONSE 1 (SOG1), a plant-specific transcription factor that governs the robust response to DNA damage, is discussed. Biology 2013, 2, 1338-1356; doi:10.3390/biology2041338

Radiation Effects. Toxicity of Plants after irradiation.• Can irradiated plant’s cells used for feeding induce radiation disease

of mammals?• Yes.

Radiation Effects. Toxicity of Plants after irradiation.• A careful analysis by FDA of all Army data present (including 31 loose-

leaf notebooks of animal feeding test results) showed significant adverse effects produced in animals fed irradiated food...• http://www.mercola.com/article/irradiated/irradiated_research.htm• In the course of legalizing the irradiation of beef, chicken, pork, fruit,

vegetables, eggs, juice, spices and sprouting seeds -- a process that has spanned nearly 20 years -- the U.S. Food and Drug Administration has dismissed or ignored a substantial body of evidence suggesting that irradiated food may not be safe for human consumption.• http://www.mercola.com/article/irradiated/irradiated_research.htm

Radiation Effects. Toxicity of Plants after irradiation.• What were these adverse effects?• A decrease of 20.7 percent in surviving weaned rats.• A 32.3 percent decrease in surviving progeny of dogs.• Dogs weighing 11.3 percent less than animals on the control diets...

Carcinomas of the pituitary gland, a particularly disturbing finding since this is an extremely rare type of malignant tumor."• Food irradiation: An FDA report. FDA Papers, Oct. 1968.

Radiation Effects. Toxicity of Plants after irradiation.• Fatal Internal Bleeding in Rats (I)• "A significant number of rats consuming irradiated beef died from 

internal hemorrhage within 46 days, the first death of a male rat coming on the 11th day of feeding. This rat became sluggish on the 8th day of the regimen and started refusing food. He continued to be morbid during the next two days, did not eat any food, lost weight and appeared anemic. He was found dead on the 11th day.• Vitamin K deficiency in rats induced by feeding of irradiated beef.• Journal of Nutrition, 69:18-21, 1959. (Cosponsored by the Surgeon

General of the US Army)

Radiation Effects. Toxicity of Plants after irradiation.• Fatal Internal Bleeding in Rats (II)• "Hemorrhagic death had occurred in all males fed irradiated diets by

day 34... There is evidence to suggest that inefficient absorption of vitamins, i.e. vitamin K, from the intestinal tract may contribute to a deficiency state." [Note: Vitamin K plays a major role in blood clotting.]• Influence of age, sex, strain of rat and fat soluble vitamins on

hemorrhagic syndromes in rats fed irradiated beef.• Federation Proceedings, 19:1045-1048, 1960. (Cosponsored by the

Surgeon General of the US Army)

Radiation Effects. Toxicity of Plants after irradiation.• Fetal Deaths in Mice• "Freshly irradiated diets produced elevated levels of early deaths in

[mice fetuses]... The increase in early deaths would suggest that the diet when irradiated has some mutagenic potential."• Irradiated laboratory animal diets: Dominant lethal studies in the

mouse.• Mutation Research, 80:333-345, 1981.• http://www.mercola.com/article/irradiated/irradiated_research.htm

Radiation Effects. Toxicity of Plants after irradiation.• Toxic effects of irradiated foods. Nature, 211:302, 1966.• A Thalidomide Warning (II)• "Irradiating can bring about chemical transformations in food and food components

resulting in the formation of potential mutagens, particularly hydrogen peroxide and various organic peroxides.• It is now realized, especially since the thalidomide episode, that older testing protocols

do not detect the more subtle population hazards such as mutagens and teratogens. In view of the serious consequences to the human population which could arise from a high level of induced mutations, it is desirable that protocols for irradiated food should include in vivo tests on mammals for possible mutagenicity."• Mutagenicity and cytotoxicity of irradiated foods and food components.• http://www.mercola.com/article/irradiated/irradiated_research.htm

Radiation Effects. Toxicity of Plants after irradiation.• Bulletin of the World Health Organization, 41:873-904, 1969. (Cosponsored by

the US Atomic Energy Commission and Food and Drug Administration)• A Host of Problems• "Numerous studies have been carried out to ascertain whether cytotoxic effects

occur when un irradiated biological test systems are cultured or fed with irradiated media or food. In such studies, adverse physiological growth retardation and inhibition, cytological cell division inhibition and chromosome aberrations and genetical effects have been observed in a wide range of test systems, ranging from bacteriophages to human cells... The available data suggest that a variety of free radicals may act as the toxic and mutagenic agents.“• http://www.mercola.com/article/irradiated/irradiated_research.htm

Radiation Effects. Toxicity of Plants after irradiation.• Cytotoxic and mutagenic effects of irradiated substrates and food 

material. Radiation Botany, 11:253-281, 1971.• A Cancer Warning• "An increase in concentration of a mutagen in food by irradiation

will increase the incidence of cancer. It will take four to six decades to demonstrate a statistically significant increase in cancer due to mutagens introduced into food by irradiation. When food irradiation is finally prohibited, several decades worth of people with increased cancer incidence will be in the pipeline.“• http://www.mercola.com/article/irradiated/irradiated_research.htm

Radiation Effects. Toxicity of Plants after irradiation.• Growth, reproduction, survival and histopathology of rats fed beef 

irradiated with electrons. Food Research, 20:193-214, 1955.• Chromosomal Damage to Human Cells (I)• "Irradiated sucrose solutions were extremely toxic to human white blood 

cells. Cell divisions were inhibited. Degenerated cell divisions were observed and the chromosomes were grossly damaged. The DNA was clumped or the chromosomes appeared shattered or pulverized. In contrast, treatment with un irradiated sucrose at the same concentration had no apparent effect on the mitotic rate and the chromosomes were not visibly damaged.“• http://www.mercola.com/article/irradiated/irradiated_research.htm

Radiation Effects. Toxicity of Plants after irradiation.• Cytotoxic and radiomimetic activity of irradiated culture medium on 

human leukocytes. Current Science, 16:403-404, 1966.• Toxic Chemical Formed in Food Containing Fat (I)• "When food containing fat is treated by ionizing radiation, a group of

2-alkylcyclobutanones [toxic chemicals] is formed. To date, there is no evidence that the cyclobutanones occur in unirradiated food. In vitro experiments using rat and human colon cells indicate that 2-dodecylcyclobutanone (2-DCB)... is clearly cytotoxic and genotoxic.“• http://www.mercola.com/article/irradiated/irradiated_research.htm

Radiation Effects. Toxicity of Plants after irradiation.• Radiation Toxins – Effects of Radiation Toxicity, Molecular 

Mechanisms of Action, Radiomimetic Properties and Possible Countermeasures for Radiation Injury.• http://www.intechopen.com/books/current-topics-in-ionizing-

radiation-research/radiation-toxins-molecular-mechanisms-of-toxicity-and-radiomimetic-properties-

Radiation Effects. Toxicity of Plants after irradiation.• Some results under way.

Radiation Effects. Toxicity of Plants after irradiation.