The origin of reactive oxygen during interaction of Pinus sylvestris root and Heterobasidion annosum s.l. – the linkage with the iron

Abstract

Reactive oxygen species (ROS) can be promoted differently, although iron is regarded as a condicio sine qua of their generation. We assessed how enzymes involved in ROS production and iron accumulation impact the interactions between Pinus sylvestris root and p at ho g e ns w i t h di ff e r e n t ho s t pr ef e r e n ce s (Heterobasidion annosum sensu stricto, H. parviporum and H. abietinum). Studies with inhibitors of ROS generation showed that diphenylene iodonium (DPI) and potassium cyanide (KCN) decreased the mortality of P. sylvestris root cells when exposed to H. parviporum in the elongation zone. In the meristematic zone, inhibited production of NADPH oxidase and oxalic acid decreased mortality of host root cells challenged with H. parviporum or H. abietinum. In the meristematic zone, iron immobilization with desferoxamine (DFO), inhibited percentage of dead host cells exposed to H. annosum s.s. Scots pine inoculation with high compatible H. annosum s.s., irrespectively in the root zone, led to an accumulation of superoxides (O 2 − ) and a colocalisation of H 2 O 2 with ferric or ferrous ions involved in production of the most harmful ROS -hydroxyl radicals at 4 h. After 48 h of mutual interaction between P. sylvestris and H. annousum s.s, a similar pattern as at 4 h was found in the root meristematic zone. We also showed that O 2 − accumulation in the P. sylvestris -H. annosum s.s. pathosystem was not NADPH oxidase dependent. During the interaction of P. sylvestris and H. annosum s.s., colocalisation of H 2 O 2 with Fe 2+ and Fe 3+ decreased by disturbing ROS production; this pattern was less apparent when H. parviporum or H. abietinum were identified as the invader. Our work implies that different mechanisms related to plant cell death can operate in both the root elongation and meristematic zone of P. sylvestris colonized with H. annosum s.s. pathosystem.

Evaluation of trophic parameters in newly built reservoir using canonical variates analysis

“…Use of CCA method enable to graphically extent interpretation of results obtained during experiment in case when observations are classified according to experimental factors. In another paper [27] positions of the pathogen isolates were presented graphically according to their differences in accumulation of reactive oxygen for data set undergoing one-way classification. In two years of studies on differences in visible tobacco leaf injury the use of CCA gave opportunity to arrange experimental objects according to rural and urban sites [28].…”

Redistribution of iron and hydrogen peroxide in Pinus sylvestris roots in response to trophically diverse fungi

“…ROS are involved at the initial stage of a plant's response to necrotrophic pathogens and mycorrhizal fungus colonization. There is growing evidence that iron may also be one of the essential factors regulating plant-fungal interactions (Expert and O'Brian 2012;Johnson et al 2007;Mucha et al 2012Mucha et al , 2015. Whether the role of iron is linked to the role of ROS generation and whether a linkage of iron and ROS to host response is dependent on the trophic strategy of the invading fungus are still not well understood.…”

“…Our previous results demonstrated that a hypersensitive response related to Fe and H 2 O 2 can regulate the initial stage of P. sylvestris root infection by the pathogen, Heterobasidion annosum s.s. (Mucha et al 2012). It was subsequently demonstrated that an iron-dependent mechanism primarily operates in the meristematic zone of P. sylvestris roots invaded by H. annosum s.s., and to a much lesser extent, in roots invaded by pathogens (H. parviporum and H. abietinum) that are more atypical for P. sylvestris (Mucha et al 2015). It is unclear, however, whether iron levels, and its distribution in different root zones, is another factor that impacts the redox state in trophically diverse fungusplant root interactions.…”

A note on testing hypotheses concerning interaction with special reference to a graphical presentation in the space of canonical variates

“…The investigations of the interaction effects between levels of two factors revealed a tendency when considering class (cell) means. Use Canonical variate analysis can be applied to other kinds of data matrix, such as matrices of one-way classification (Mucha et al 2015), two-way classification with one observation per cell (Kayzer et al 1999, block designs (Lejeune 2000) and other factorial designs (Budka et al 2015). Canonical variate analysis is similar to another procedure called principal component analysis.…”