Flax (Linum usitatissimum L.) is an important crop for the production of oil and fiber. In vitro manipulations of flax are used for genetic improvement and breeding while improvements in adventitious root formation are important for biotechnological programs focused on regeneration and vegetative propagation of genetically valuable plant material. Additionally, flax hypocotyl segments possess outstanding morphogenetic capacity, thus providing a useful model for the investigation of flax developmental processes. Here, we investigated the crosstalk between hydrogen peroxide and auxin with respect to reprogramming flax hypocotyl cells for root morphogenetic development. Exogenous auxin induced the robust formation of adventitious roots from flax hypocotyl segments while the addition of hydrogen peroxide further enhanced this process. The levels of endogenous auxin (indole-3-acetic acid; IAA) were positively correlated with increased root formation in response to exogenous auxin (1-Naphthaleneacetic acid; NAA). Histochemical staining of the hypocotyl segments revealed that hydrogen peroxide and peroxidase, but not superoxide, were positively correlated with root formation. Measurements of antioxidant enzyme activities showed that endogenous levels of hydrogen peroxide were controlled by peroxidases during root formation from hypocotyl segments. In conclusion, hydrogen peroxide positively affected flax adventitious root formation by regulating the endogenous auxin levels. Consequently, this agent can be applied to increase flax regeneration capacity for biotechnological purposes such as improved plant rooting.
- MeSH
- antioxidancia metabolismus MeSH
- biotechnologie MeSH
- hypokotyl účinky léků růst a vývoj metabolismus MeSH
- kořeny rostlin účinky léků růst a vývoj metabolismus MeSH
- kyseliny indoloctové metabolismus MeSH
- kyseliny naftalenoctové farmakologie MeSH
- len účinky léků růst a vývoj metabolismus MeSH
- peroxid vodíku metabolismus farmakologie MeSH
- přeprogramování buněk účinky léků MeSH
- regulátory růstu rostlin metabolismus farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
Understanding similarities and differences in population dynamics of closely related species is a key prerequisite in attempts to apply knowledge obtained in one species to another species, e.g., for the purpose of predicting future fate of populations of various rare species. It can be expected that species will have similar population dynamics if they are closely related and share similar habitats. Contrasting population sizes and distribution patterns may, however, indicate that the population dynamics will be different. To understand similarities and differences in population dynamics of closely related species, I studied demography of two congeneric endangered species, Linum flavum and L. tenuifolium co-occurring in dry grasslands. Linum flavum occurs with a lower number of large populations, while L. tenuifolium occurs as a large number of small populations. The results showed that L. flavum had higher population growth rates, relied more on survival and growth and its populations were more persistent. In contrast, populations of L. tenuifolium were more prone to extinction and frequent recolonisation was necessary for their survival in the landscape. This was in accordance with observed population sizes of the two species and their frequency in the landscape. The results indicate that despite being closely related and occurring in the same habitat types, the two Linum species have different growth strategies. The strong differences in population dynamics between the two species suggest that similarity in population sizes and frequency of the species in the landscape may be more important when attempting to transfer knowledge between species than is taxonomic relatedness.
- MeSH
- biomasa MeSH
- demografie MeSH
- druhová specificita MeSH
- ekosystém MeSH
- klíčení MeSH
- květy růst a vývoj fyziologie MeSH
- len růst a vývoj fyziologie MeSH
- rozmnožování MeSH
- semena rostlinná růst a vývoj fyziologie MeSH
- stadia vývoje MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Geografické názvy
- Česká republika MeSH
The effect of toxic metals on seed germination was studied in 23 cultivars of flax (Linum usitatissimum L.). Toxicity of cadmium, cobalt, copper, zinc, nickel, lead, chromium, and arsenic at five different concentrations (0.01-1 mM) was tested by standard ecotoxicity test. Root length was measured after 72 h of incubation. Elongation inhibition, EC50 value, slope, and NOEC values were calculated. Results were evaluated by principal component analysis, a multidimensional statistical method. The results showed that heavy-metal toxicity decreased in the following order: As3+>or=As5+>Cu2+>Cd2+>Co2+>Cr6+>Ni2+>Pb2+>Cr3+>Zn2+.
- MeSH
- arsen toxicita MeSH
- biodegradace MeSH
- chrom toxicita MeSH
- inhibitory růstu toxicita MeSH
- kadmium toxicita MeSH
- klíčení účinky léků MeSH
- kobalt toxicita MeSH
- kořeny rostlin účinky léků růst a vývoj MeSH
- látky znečišťující půdu toxicita MeSH
- len klasifikace účinky léků růst a vývoj MeSH
- měď toxicita MeSH
- nikl toxicita MeSH
- olovo toxicita MeSH
- testy toxicity MeSH
- těžké kovy toxicita MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- zinek toxicita MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
