Young pea plants grown as a water culture were sprayed with hydrogen peroxide and 24 h later were treated with the herbicide paraquat. The effects of paraquat and H2O2 treatment were investigated on the endogenous con...Young pea plants grown as a water culture were sprayed with hydrogen peroxide and 24 h later were treated with the herbicide paraquat. The effects of paraquat and H2O2 treatment were investigated on the endogenous concentrations of free proline, and free and conjugated putrescine, spermidine and spermine. Application of PQ increased the free proline and Put, and decreased conjugated and bound polyamines. The results clearly demonstrate the oxidative damages provoked by PQ application. Single treatment with H2O2 provoked considerable decrease in the free fraction of the three PAs studied 2 h after light exposition, but caused an increase in their respective conjugated fractions. Data suggest that PA changes after H2O2 treatment are due to conversion from free to conjugated form. Three hours later free PAs in H2O2 treated-plants reached control levels;however the conjugated remained higher than the control. No alterations were detected in proline concentration after H2O2 treatment. Pretreatment with Н2О2 activated some component of the plant protection mechanisms by causing an alteration in free/conjugated PAs ratio in plants subsequently subjected to PQ treatment. Data concerning PA and proline concentrations in plants treated with both compounds supposed that H2O2 shows a protective role against PQ and improves the plant tolerance to the oxidative stress generated by paraquat.展开更多
Polyamines are small nitrogen-containing organic molecules, which are widely distributed in plants. They are involved in the regulation of normal plant growth and developmental processes. In this study we examined the...Polyamines are small nitrogen-containing organic molecules, which are widely distributed in plants. They are involved in the regulation of normal plant growth and developmental processes. In this study we examined the role of polyamines on the growth of Cucurbita pepo L.(zucchini) cotyledons incubated on solutions of different types of cytokinins (BA—N6-benzylaminopurine or 4PU-30—N1-(2-chloro-4-pyridyl)-N2-phenylurea) and copper in excess. We found that endogenous polyamines, and mainly the conjugated fraction, are involved in the cell division processes of isolated zucchini cotyledons and their changes are related to the specific action of the used growth regulating factors.展开更多
The paper studies the effect of incubation of rhizobia with soybean seeds lectin on formation and functioning of alfalafa-Sinorhizobium meliloti symbiosis under the optimal water supply and drought conditions. It was ...The paper studies the effect of incubation of rhizobia with soybean seeds lectin on formation and functioning of alfalafa-Sinorhizobium meliloti symbiosis under the optimal water supply and drought conditions. It was shown that the addition of lectin to the inoculation compositions intensifies physiological processes in alfalfa plants： increases nitrogen fixing activity of symbiosis, nodule number on roots, as well as chlorophyll and carotenoid content in leaves, enhances plant growth during budding-fruiting period and reduces the negative effect of drought on alfalfa productivity.展开更多
This paper focuses on the advantages of derivative vegetation indices over simple reflectance- based indices that are traditionally used for remote sensing of vegetation. The idea of using reflectance derivatives inst...This paper focuses on the advantages of derivative vegetation indices over simple reflectance- based indices that are traditionally used for remote sensing of vegetation. The idea of using reflectance derivatives instead of simple reflectance spectra was proposed several decades ago. Despite this, it has not been widely used in monitoring systems because the derivatives lack reliable parameters. In addition, most satellite monitoring systems are not equipped with hyperspectral sensors, which are considered necessary for operating with the reflectance derivatives. Here, we present original data indicating that the chlorophyll-related derivative index D725/D702 we derived can be accurately estimated from a reflectance spectrum of 10 nm resolution that would be suitable for most satellite-based sensors. Furthermore, the index is not sensitive to soil reflectance and can therefore be used for testing of open crops. Presence of blanc reflectance is also unnecessary. Preliminary results of index testing are presented. Perspectives on using this and other derivative indices are discussed.展开更多
文摘Young pea plants grown as a water culture were sprayed with hydrogen peroxide and 24 h later were treated with the herbicide paraquat. The effects of paraquat and H2O2 treatment were investigated on the endogenous concentrations of free proline, and free and conjugated putrescine, spermidine and spermine. Application of PQ increased the free proline and Put, and decreased conjugated and bound polyamines. The results clearly demonstrate the oxidative damages provoked by PQ application. Single treatment with H2O2 provoked considerable decrease in the free fraction of the three PAs studied 2 h after light exposition, but caused an increase in their respective conjugated fractions. Data suggest that PA changes after H2O2 treatment are due to conversion from free to conjugated form. Three hours later free PAs in H2O2 treated-plants reached control levels;however the conjugated remained higher than the control. No alterations were detected in proline concentration after H2O2 treatment. Pretreatment with Н2О2 activated some component of the plant protection mechanisms by causing an alteration in free/conjugated PAs ratio in plants subsequently subjected to PQ treatment. Data concerning PA and proline concentrations in plants treated with both compounds supposed that H2O2 shows a protective role against PQ and improves the plant tolerance to the oxidative stress generated by paraquat.
文摘Polyamines are small nitrogen-containing organic molecules, which are widely distributed in plants. They are involved in the regulation of normal plant growth and developmental processes. In this study we examined the role of polyamines on the growth of Cucurbita pepo L.(zucchini) cotyledons incubated on solutions of different types of cytokinins (BA—N6-benzylaminopurine or 4PU-30—N1-(2-chloro-4-pyridyl)-N2-phenylurea) and copper in excess. We found that endogenous polyamines, and mainly the conjugated fraction, are involved in the cell division processes of isolated zucchini cotyledons and their changes are related to the specific action of the used growth regulating factors.
文摘The paper studies the effect of incubation of rhizobia with soybean seeds lectin on formation and functioning of alfalafa-Sinorhizobium meliloti symbiosis under the optimal water supply and drought conditions. It was shown that the addition of lectin to the inoculation compositions intensifies physiological processes in alfalfa plants： increases nitrogen fixing activity of symbiosis, nodule number on roots, as well as chlorophyll and carotenoid content in leaves, enhances plant growth during budding-fruiting period and reduces the negative effect of drought on alfalfa productivity.
文摘This paper focuses on the advantages of derivative vegetation indices over simple reflectance- based indices that are traditionally used for remote sensing of vegetation. The idea of using reflectance derivatives instead of simple reflectance spectra was proposed several decades ago. Despite this, it has not been widely used in monitoring systems because the derivatives lack reliable parameters. In addition, most satellite monitoring systems are not equipped with hyperspectral sensors, which are considered necessary for operating with the reflectance derivatives. Here, we present original data indicating that the chlorophyll-related derivative index D725/D702 we derived can be accurately estimated from a reflectance spectrum of 10 nm resolution that would be suitable for most satellite-based sensors. Furthermore, the index is not sensitive to soil reflectance and can therefore be used for testing of open crops. Presence of blanc reflectance is also unnecessary. Preliminary results of index testing are presented. Perspectives on using this and other derivative indices are discussed.
