|
Analýza tvorby buněk sekundárního xylému a floému borovice lesní (Pinus sylvestris L.) v reakci na stres suchem
Fajstavr, Marek
Scots pine (Pinus sylvestris L.) is a long-term economically preferred woody species not only from the standpoint of its wood production but also thanks to its tolerance to extreme climatic factors, environmental modesty, and resistance to drought stress. In recent years, however, due to the action of the changing climatic conditions, this economically significant woody species withers. Its increment in the natural ecotype is affected by the adaptability to the increasing intensity of temperature extremes (prolonged heat waves). The combination of the lack of precipitation and extremely high air temperatures (even in the spring season) will significantly affect the resistance of this woody species to drought stress. This thesis is focused on the analysis of the secondary xylem and phloem cells formation of Scots pine depending on the physiological and morphological changes due to the affecting drought stress. Within the scope of the forming radial cells in individual growing seasons (2013–2016), it has been evaluated how the synergy of the specific factors affecting the overall anatomic structure of the annual ring and the vitality of the examined woody species was expressed in the formation, differentiation, and overall structure of the cells. During the four growing seasons (2013–2016), micro-cores (diameter 1.8 mm) were taken in weekly intervals in the research area in Sobesice of xylem and phloem (including the cambial zone) using the Trephor increment borer. From these micro-cores, permanent microscopic slides of the cross-section were made, on which the analysis of the cambial activity, cell formation, cell differentiation with time, and the evaluation of the morphometric parameters of the formed of xylem and phloem cells were performed. It was found that in each monitored growing season, the drought stress has shown, which was reflected by the dropped of the soil water potential (below -1 MPa) and the intensity of transpiration, which led to the stress reaction of the cambium. The reaction of the drought-stressed cambial zone has been expressed by the decreased activity (a sudden drop of the number of dividing cells) and subsequently, during the recurrence of precipitation, by the reactivation when an increase of the number of dividing cells was observed again. This factor initiated the formation of the intra-annual density fluctuations (IADF), i.e. the formation of the so-called false annual ring. The sensitive reaction of the cambium to the drought stress affected the cell production time, the number of formed cells, and also the time of differentiation of individual tracheids, which was expressed by the reduction of the radial dimensions and cell wall thickness of the tracheids. The artificially induced stress by stem girdling intensified the concurrent drought factor and in the area below the girdling, the cambial activity has stopped within two weeks after the performed treatment. The formed cells were not fully differentiated, so the zone of typically thick-walled cells of latewood was missing in the annual ring. The following growing season, the radial increment was only formed in the area above the girdling (without the latewood zone) and in the second half of the growing season, the trees gradually died. The activity of the plant hormone IAA was also affected by the drought in the summer season, when its concentration dropped below the measurability threshold (2 µg sample-1). At the time of the IAA concentration drop, latewood tracheids began to form and the phloem cell formation was completed. The synthesis and activity of the soluble low-molecular carbohydrates correlated with the course of the cambial activity and the cell differentiation phases, where the dynamics of the concentration also matched the timing of the formation of the individual cell formation phases. With phloem cells, a significant variability in the morphological dimensions has not been observed compared to xylem cells. The phenology of the needles indicated the cell wall formation phases and the initiation of the latewood tracheids. Due to the fact that the needles were fully formed in the season of the spring tracheids formation, their phenology did not reflect the drought stress which was recorded mainly in the summer season. Also, the increment of phloem was formed in the spring season. It has been presented for a long time that coniferous woody species react to the drought stress by thicker cell walls formation of the latewood tracheids. However, it has been observed within the scope of the research of this thesis that the water deficit affected the cambial activity, which has expressed itself on the intensity of the cell formation and the time of their differentiation. Due to this process, tracheids with smaller radial dimensions and a narrower cell wall were formed. This gradually causes structural changes of the formed annual ring, where the typically earlywood and latewood tracheids (classified according to radial dimensions and thicknesses of cell walls) may form independently on the growth seasonality. Especially in cases of IADF formation or in combination with the case where latewood is not even formed, a problem with the validity of the classification according to the so-called Mork’s criterion begins to occur. The understanding of the effect of the specific metabolic and physiological changes on xylem and phloem formation of Scots pine helps to clarify the issues of forestation and overall wood production of this economically significant woody species.
|
|
Molecular detection of genes involved in drought stress reaction in opium poppy
ŠEFČÍKOVÁ, Miroslava
Drought belongs among one of the main abiotic factors that influence the yield and quality of agricultural crops. However, plants fight these negative environmental impacts by mechanisms developed during evolution. One of these mechanisms is the plants´ response on molecular level, which is gene expression. These genes potentially reacting to drought include the following genes: MLP43 and SDD1. For the purposes of molecular detection of these genes, the DNA from opium poppy plants (Papaver somniferum L.) Orel and Onyx type, was necessary to be isolated. Further, primer sets for the genes of MLP43 and SDD1 were designed. The chosen primer sets were used for analysis purposes using the real-time PCR method. The PCR method was also optimized.
|
|
Impact of nitrogen fertilization and drought on gliadins content in winter wheat
Odstrčilová, Eva ; Obruča, Stanislav (referee) ; Hrstka, Miroslav (advisor)
In this diploma thesis the impacts of both nitrogen fertilization and drought on the content of proteins of the gliadin fraction in case of a winter wheat variety Tiguan were observed. Selected samples were cultivated at two locations in a total duration of two years. Two different conditions were selected: one without the nitrogen fertilization (0 kg N/ ha) and the other with the nitrogen fertilization in 140 kg N/ ha concentration. Second observed factor was the drought which was ensured by roofs above the crops and their cultivation in common climatic environment. Gliadin fraction was separated by the A-PAGE method and the protein quantification carried out by a computer densitometry. Such nitrogen fertilization caused a significant increase of gliadins, especially -1,2 and -5 fractions. Stress induced by the drought caused an increase of gliadin content compared to the control sample, particularly in case of - and - fractions. The most important factor influencing the gliadin content in grains was therefore the nitrogen fertilization in a dry environment. The observed increase of gliadin content was lower in case of the sample which was fertilized in a humid environment than in case of the sample which was fertilized in the dry one.
|
|
Effect of drought on the metabolism of tobacco plants
Miedzińska, Lucia ; Ryšlavá, Helena (advisor) ; Vaňková, Radomíra (referee)
EEffffeecctt ooff ddrroouugghhtt oonn tthhee mmeettaabboolliissmm ooff ttaabbaaccccoo ppllaannttss (Nicotiana tabacum L.) Diploma thesis - abstract Lucia Miedzińska, Bc. Work Supervisor: Doc. RNDr. Helena Ryšlavá, CSc. Consultant: RNDr. Veronika Doubnerová, PhD. Drought stress is one of the most frequent form of plant stress, which occurs not only under condition of limited water availability, but also under reduced ability to accept water by roots, for example in salted or cold soils. In this thesis the changes in enzyme activities of: NADP-malic enzyme (EC 1.1.1.40; NADP-ME), phosphoenolpyruvate carboxylase (EC 4.1.1.31; PEPC) and pyruvate, phosphate dikinase (EC 2.7.9.1; PPDK) in tobacco plants (Nicotiana tabacum L., cv. W38) after drought were investigated. Enzyme activities in tobacco leaves were significantly increased during 11 days of stress, PEPC 2-fold, PPDK 3,3- fold and NADP-ME 4-fold compared to control plants. The regulation of NADP-ME and PEPC activities were studied on transcriptional level - by the real-time PCR method and on translational level - immunochemically. The expression of NADP-ME protein and transcription of mRNA for chloroplast NADP-ME isoform were increased, but mRNA for cytosolic isoform was not affected. The protein expression of PEPC was slightly increased, transcription of...
|
|
Environmental factors effect to the Scotch pine seedlings survival
Pourová, Marie ; Ulbrichová, Iva (advisor) ; Janeček, Vladimír (referee)
The survival and mortality of the Scots Pine (Pinus sylvestris) seedlings during the vegetation season of 2015 are evaluated in the thesis. The seedlings in greenhouse conditions in Truby were exposed to water deficiency, three variants of shading and simultaneously to environmental temperature, which, due to weather, was extraordinary high at the time of the experiment.
The highest number of grown seedlings from the seed material from Plasy was 89 % from the total of 224 outplanted ones, namely in conditions of mean shading and slightly reduced watering. The highest mortality of the seedlings was found in unshaded environment with slightly reduced watering, in mean shading with the second lowest watering and in the highest shading with the second lowest watering, the mortality was 100 % there. The seedlings from the seed material from Doksy were much more hard put to it. The seedlings grew only in four cases in unshaded environment with the highest watering (4 % from 224 outplanted ones), in mean shading with the highest watering (38 %) and in the environment with the highest shading together with the highest watering (68 %) and slightly lowered watering (1,3 %). In all cases the seedlings mortality was higher than 70 %.
The lowest number of grown seedlings occurred in unshaded environment and between the variants with mean and high shading, there was only a small difference. The results were strongly affected by extraordinary warm vegetation season.
|
|
Effect of drought stress factor on glycoalkaloid contents in potato (Solanum tuberosum L.)
Matoušková, Vendula ; Kotíková, Zora (advisor) ; Martinková, Jaroslava (referee)
Potatoes are an important and irreplaceable crop. This kind of crop is very important not only for it is use but also for a nutrition composition. There are also a prominent source of vitamins, minerals and antioxidants. Outside substances beneficial to health and potatoes contain harmful substances. These substances are foreign or naturally occurring, which include toxic glycoalkaloids. Glycoalkaloids are secondary metabolites of plants. Glycoalkaloids in potatoes have protective function it can increase the synthesis for example in case of pest infestations, mechanical damage or in case of to much light and heat. The potatoes were found several glycoalkaloides. Main, which constitutes 95 % of their content, are alpha-chaconine and alpha-solanine. Their toxicity is inhibition of acetylcholinesterase and breaking the cell membranes. The potato tuber is their content is distributed unevenly. The quantity of glycoalkaloids is affected by manny factors as for example place, year, kind, the way how the crops are grown and storage. In Czech Republic the maximum allowed limit of glycoalkaloides in potatoes were made by legislation on 200 mg/kg fresh potato matter. In the commonly grown varieties of the amount is far below the hygienic limit. The methods for isolation of glycoalkaloids in potatoes are mainly chromatographic. The most commonly used HPLC (high performance liquid chromatography). In performed experiment was determined the content of majority glycoalkaloid alpha- chaconinu and alpha-solaninu at four different kinds -Milva, Marabel, Laura and Valfi. Drought stress has been studied for their content, assuming their accumulation in comparison with the other two variants - irrigation watering and drip irrigation. The glycoalkaloides content were messured by the UHPLC/MS/MS. The obtained results concluded that the content of glycoalkaloids is the variety dependent. Drought stress can probably increase their content. In our experiment, it positively did not. Important is the choice of kind in case if expectation a hot and dry year of growing. Kinds Milva and Marabel are very good in these conditions. In the case of general principles for cultivation, storage and cooking, the glykoalkaloids does not vision a risk for the consumer.
|
|
Vliv zvýšené koncentrace CO2 a sucha na rychle rostoucí dřeviny
Vágner, Lukáš
The main objective of this study was to determine the effect of elevated CO2 and drought on growth of fast-growing trees, hence hybrids of poplar Populus nigra and Populus maximowiczii on experimental station Domanínek. These parameters were measured: photosynthesis, reflectance, fluorescence of chlorophyll and content of chlorophylls and flavonols. The results show a demonstrable effect of greater regulatory abilities stomatas at elevated CO2 concentration, which leads to greater efficiency of water use. Decisive influence on leaf area, specific leaf area and the dry weight has the effect of drought. However, for specific leaf area, contrary to expectations, there was an noticeable increase during drought period. In the case of other characteristics come to reduce them. By contrast specific leaf area slightly decreases at elevated CO2 concentration. Rate of photosynthesis increases with increasing concentrations of CO2, while the effect of drought dampens these characteristics and also reduces the chlorophyll content. Increasing concentration of CO2 during the experiment also leds to an increase in NDVI index, which shows increased chlorophyll content. The values of fluorescence at two concentrations of CO2 when exposed to drought stress differed minimally. The maximum quantum yield of photosystem II is slightly higher at elevated CO2 concentration. Overall, it can be summarized that in the short-term effect of drought stress in hybrid poplar, increased concentration of CO2 increases water use efficiency and thus to mitigate the impact of drought on photosynthetic parameters.
|
| |
|
The response of Norway spruce and European beech's photosynthetic apparatus to some stress factors - comparative study
NOVÁKOVÁ, Hana
In the context of expected climate changes is more and more important to study how will species of present ecosystems react to this changes. Thus this study is focused on reactions of two main forest tree species of Central Europe ? Norway spruce (Piacea abies L.) and European beech (Fagus sylvatica L.) ? to water stress, higher quantity of N in soil, combination of theese stress factors and heat stress. The effects of stress were monitored on maximal photochemical efficiency of PS II (Fv / Fm) and on contents of photosynthetic pigments. It was found that Norway spruce is more resistant to all mentioned stress factors than European beech.
|