The effect of ionizing radiation on plants has been studied with several purposes. Ionizing radiation has been used to generate stable mutants in breeding programs, or as a substitute for conventional decontamination methods. However, the larget amount of data on the effects of ionizing radiation on plants was obtained from radioecology studies, as well as from Space exploration applications. Events as Chernobyl or Fukushima disasters created “natural experimental fields” where to study radiation effects in contaminated ecosystems. The direct effects of radionuclides on plants and indirect long-term effects due to the contamination of other components of the ecosystem have been widely explored. However, Space biology is currently one of the most active fields in which radiation effects on plants are studied (1). In the sight of long duration exploratory-class manned missions, like the one towards Mars or the deep space, the protection of organisms from cosmic radiation is considered one of the main challenges (2). In such missions, plant cultivation is mandatory, since plants not only have an important role in mitigating psychological stress due to isolation, but are also key organisms for regeneration in artificial ecosystem (e.g. Bioregenerative Life Support Systems). Plants regenerate oxigen through photosynthesis, allow water recovery through transpiration, participate in waste recycling, and produce fresh food (3). However, the Space is an extreme environment where ionizing radiation is known to influence deeply organisms’ growth at molecular, morpho-structural, physiological and biochemical levels, thus affecting the efficiency of plants as regenerators. Herein, we summarize the key results of many experiments performed on crop species (e.g. soybean, Glycine max (L.) Merr.; azuki bean, Vigna radiata (L.) R. Wilczek; dwarf bean, Phaseolus vulgaris L.; tomato, Solanum lycopersicum L.), where plants, during several phenological phases; have been exposed to ionizing radiation. Seeds and adult plants were exposed to different types of radiation (e.g. Low- and High-LET, Linear Energy Transfer), and at different doses. The combined effect of radiation and other environmental factors, such as light quality, has also been investigated. The consequence of irradiation was assessed through the analysis of morphological development, some molecular traits, anatomical features of leaves and fruits, photosynthesis, flowering phenology, fruit development, and nutritional traits. Depending on several factors, including species, cultivar, plant phenological stage and traits of the target tissue/organ, the exposure to ionizing radiation produces several effects, which range from detrimental outcomes at very high doses, harmful consequences at intermediate levels, and stimulatory effects at very low doses. A severe interaction with other factors has also been evidenced. The interaction between factors and the different radiosensitivity of plants should be taken into account in ecosystem recovery in case of radiation contamination, as well as in the development of artificial ecosystems in extreme environments like Space.
Morpho-functional plant traits conferring radioresistance: living in extreme conditions by transforming constraints in opportunities / De Micco, V.; Amitrano, C.; Vitale, E.; Aronne, G.; Arena, C.. - unico:(2018), pp. 58-58.
Morpho-functional plant traits conferring radioresistance: living in extreme conditions by transforming constraints in opportunities
De Micco V.;Amitrano C.;Vitale E.;Aronne G.;Arena C.
2018
Abstract
The effect of ionizing radiation on plants has been studied with several purposes. Ionizing radiation has been used to generate stable mutants in breeding programs, or as a substitute for conventional decontamination methods. However, the larget amount of data on the effects of ionizing radiation on plants was obtained from radioecology studies, as well as from Space exploration applications. Events as Chernobyl or Fukushima disasters created “natural experimental fields” where to study radiation effects in contaminated ecosystems. The direct effects of radionuclides on plants and indirect long-term effects due to the contamination of other components of the ecosystem have been widely explored. However, Space biology is currently one of the most active fields in which radiation effects on plants are studied (1). In the sight of long duration exploratory-class manned missions, like the one towards Mars or the deep space, the protection of organisms from cosmic radiation is considered one of the main challenges (2). In such missions, plant cultivation is mandatory, since plants not only have an important role in mitigating psychological stress due to isolation, but are also key organisms for regeneration in artificial ecosystem (e.g. Bioregenerative Life Support Systems). Plants regenerate oxigen through photosynthesis, allow water recovery through transpiration, participate in waste recycling, and produce fresh food (3). However, the Space is an extreme environment where ionizing radiation is known to influence deeply organisms’ growth at molecular, morpho-structural, physiological and biochemical levels, thus affecting the efficiency of plants as regenerators. Herein, we summarize the key results of many experiments performed on crop species (e.g. soybean, Glycine max (L.) Merr.; azuki bean, Vigna radiata (L.) R. Wilczek; dwarf bean, Phaseolus vulgaris L.; tomato, Solanum lycopersicum L.), where plants, during several phenological phases; have been exposed to ionizing radiation. Seeds and adult plants were exposed to different types of radiation (e.g. Low- and High-LET, Linear Energy Transfer), and at different doses. The combined effect of radiation and other environmental factors, such as light quality, has also been investigated. The consequence of irradiation was assessed through the analysis of morphological development, some molecular traits, anatomical features of leaves and fruits, photosynthesis, flowering phenology, fruit development, and nutritional traits. Depending on several factors, including species, cultivar, plant phenological stage and traits of the target tissue/organ, the exposure to ionizing radiation produces several effects, which range from detrimental outcomes at very high doses, harmful consequences at intermediate levels, and stimulatory effects at very low doses. A severe interaction with other factors has also been evidenced. The interaction between factors and the different radiosensitivity of plants should be taken into account in ecosystem recovery in case of radiation contamination, as well as in the development of artificial ecosystems in extreme environments like Space.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
