Ecophysiological approach to study of the role of cell-bound peroxidase forms in wheat leaves of different morphology

Extracellular peroxidase enzymes, both ionically - and covalently bound, have been implicated in the biochemical changes of cell wall and furthermore for regulation of leaf and root extension growth. However, the role of cell wall bound peroxidase in changes of mature leaf morphology is poorly understood. The aim of this study was to determine whether ionically and covalently bound peroxidase activities exhibit any relationships with drought-induced leaf rolling of wheat. An activity and thermostability of three wheat genotypes with different leaf rolling degree were studied. The results clearly show that two genotypes with leaf rolling trait exhibited significantly higher activity of both extracellular peroxidase fractions in comparison to non-rolling cv. 'Omskaya 9'. In addition, the significant genotypic differences were found in thermostability of ionically and covalently bound peroxidase. A 35 °C-treatment decreased the activity of ionically bound peroxidase (IBP) in non-rolling leaves of parent cultivar and enhanced the activity of IBP in rolling leaves of 'Alba' genotype. Under 45 and 55 °C-treatment the IBP was more stable in rolling leaves of both genotypes 'Otan' and 'Alba'. Despite to low activity of covalently bound peroxidase it was more stable after heating by 45 °C compare with ionically bound fraction. The heating of covalently bound peroxidase (CBP) extracts by 35 °C and 45 °C also has enhancing effect on its activity by both leaf rolling genotypes (on 16 and 40% by 'Otan' and 'Alba', respectively). At the same time the CBP activity of non-rolling genotype decreased significantly on 40%. Even after 55 °C-treatment the CBP of both rolling genotypes remained very stable, although there were further inhibition of CBP purificated from leaves of non-rolling genotype. Both wheat genotypes with inserted leaf rolling trait exhibited a much higher blue-green fluorescence emission than non-rolling leaves of parent cultivar 'Omskaya 9'. Thus, the molecular mechanism of leaf rolling regulation seems to include an adjustment of cell wall properties and probably involves an activity of cell wall bound peroxidase. Further investigation is expected to reveal the regulatory mechanism for leaf rolling in wheat

The Essential Approaches and Methods of Teaching Music

Music plays an important role in our cultural life and in the development of human beings. Proper organization of the activities of all the senses is very important in the reception and acquisition of knowledge. The more members of the senses are involved, the easier it is to know. Demonstration is also an important law of music teaching, as the nature of this science requires more demonstration. This article discusses about the essential approaches and methods of teaching musi

Photosynthesis performance of non-rolling and flag leaf rolling wheat genotypes during temperature stress

The objective of this study is to determine the potential of photosynthesis for the detection of heat stress in three wheat genotypes ‘Grekum 476’, ‘Otan’ and ‘Alba’, which are known to differ in their leaf rolling ability. The results of measurements of gas-exchange, stomatal conductance and pigment determination indicate that the use of a temperature of 40 °C allows to distinguish the non-rolling and leaf rolling wheat genotypes in their photosynthetic responses to heat stress.High temperature acclimation by the leaf rolling wheat genotypes caused marked changes in the pigment composition and function of the photosynthetic apparatus. Thus, stomatal regulation (changes in gH 2 O values), the changes in WUE and modification of the photosynthetic pigment apparatus as well as the up-rolling of the flag leaf at a higher irradiance are essential factors that contribute to avoid heat and drought conditions as well as photoinhibition of the photosynthetic apparatus in major parts of the leaf. The two most leaf up-rolling wheat genotypes ‘Grekum 476’ and ‘Otan’ also exhibited the best stomata regulation, a higher WUE and the highest P N -rates at a 40 °C heat stress than the non-rolling ‘Omskaya 9’ or the low leaf rolling ‘Alba’ genotypes. Thus, photosynthetic net CO 2 assimilation P N and the high degree of flag leaf up-rolling under heat conditions parallel the higher field productivity of ‘Grekum 476’ and ‘Otan’