Number of results to display per page
Search Results
192. The use of a portable non-destructive type nitrogen meter for leaves of woody plants in field studies
- Creator:
- Ichie, T., Kitahashi, Y., Matsuki, S., Maruyama, Y., and Koike, T.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Agriexpert PPW-3000, chlorophyll, comparison of methods, and SPAD-502
- Language:
- Multiple languages
- Description:
- The practicality of the portable, non-destructive type nitrogen meter (Agriexpert PPW-3000) was tested on ten forest species. Also investigated was the potential relationship between leaf nitrogen and chlorophyll (Chl) contents and the readings taken with the PPW-3000 and a Chl meter (SPAD-502). There was a significantly positive correlation between the readings of PPW-3000 and N content in the same leaves, whereas the correlation between leaf Chl content and the PPW-3000 values was less positive. Similarly there was a significant positive correlation between actual Chl content and the SPAD-502 readings and the less positive correlation between actual N content and the SPAD-502 readings. Thus using both the PPW-3000 and SPAD-502 enables to determine leaf N and Chl contents simply and non-destructively in the field. and T. Ichie ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
193. Treatment with methyl jasmonate alleviates the effects of paraquat on photosynthesis in barley plants
- Creator:
- Hristova, V. A. and Popova, L. P.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- barley, catalase, chlorophyll, glycolate oxidase, Hordeum vulgare, methyl jasmonate, paraquat, phosphoglycolate phosphatase, photorespiration, ribulose-1,5 bisphosphate carboxylase, and transpiration rate
- Language:
- Multiple languages
- Description:
- Twelve-day-old barley seedlings were supplied with 23 μM methyl jasmonate (MeJA) or 10 μM paraquat (Pq) via the transpiration stream and kept in the dark for 24 h. Then they were exposed to 100 μmol m-2 s-1 PAR and samples were taken 1, 2, 3, and 6 h after irradiation. Treatment of seedlings with MeJA alone resulted in decreased content of chlorophyll (Chl), and net photosynthetic (PN) and transpiration rates. Pq treatment led to a decrease in Chl content and to a very strong inhibition of PN, the effects were manifested by 1 h of irradiation. Pq treatment did not affect the activity of ribulose-1,5 bisphosphate carboxylase (RuBPC, EC 4.1.1.39) but increased the activity of the photorespiratory enzymes phosphoglycolate phosphatase (PGP, EC 3.1.3.18), glycolate oxidase (GO, EC 1.1.3.1), and catalase (EC 1.11.1.6). Pre-treatment of seedlings with MeJA before exposure to Pq fully blocked the inhibitory effect of Pq on photosynthesis and protected against subsequent Pq-induced oxidative damage. and V. A. Hristova, L. P. Popova.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
194. Ultraviolet-B induced changes in ultrastructure and D1/D2 proteins in cyanobacteria synechococcus sp. PCC 7942
- Creator:
- Chauhan, Sanjay, Pandey, Ritu, and Singhal, Gauri S.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- carotenoids, cell shape, chlorophyll, phycocyanin, and thylakoid
- Language:
- Multiple languages
- Description:
- Effects of ultraviolet-B (UV-B) irradiation on ultrastructure, total cellular protein, and PS2 proteins D1 and D2 of Synechococcus sp. PCC 7942 cells was studied. The scanning electron micrographs showed UV-B radiation induced bending of the cells. The transmission electron micrographs revealed disorganization and shift in thylakoid lamellar structure to one side of the cell. The cellular phycocyanin/chlorophyll ratio decreased with increasing UV-B treatment and due to this the colour of cells turned light-green. No apparent change in total cellular proteins was evident, but the contents of two major proteins of PS2, D1 and D2, showed decline due to UV-B irradiation, although to different extent. and Sanjay Chauhan, Ritu Pandey, Gauri S. Singhal.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
195. Uniconazole (S-3307) induced protection of Abelmoschus ssculentus L. against cadmium stress
- Creator:
- Purohit, S. and Singh, V. P.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- biomass, chlorophyll, detoxification, growth, and Hill reaction activity
- Language:
- Multiple languages
- Description:
- In Abelmoschus esculentus L. uniconazole brought about a marked decrease in cadmium-induced loss of chlorophyll and Hill reaction activity, but it did not completely prevent cadmium toxicity. and S. Purohit, V. P. Singh.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
196. Utilization of photosynthetically fixed 14CO2 into alkaloids in relation to primary metabolites in developing leaves of Catharanthus roseus
- Creator:
- Srivastava, N. K., Misra, A., Srivastava, A. K., and Sharma, S.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- amino acids, chlorophyll, leaf area and dry mass, leaf ontogeny, net photosynthetic rate, organic acids, sugars, terpenoids, and total alkaloids
- Language:
- Multiple languages
- Description:
- Partitioning of current photosynthates towards primary metabolites and its simultaneous incorporation in leaf alkaloids was investigated in developing leaves of medicinally important Catharanthus roseus. Of the total 14CO2 assimilated, the leaves at positions 1-6 fixed 8, 22, 25, 19, 13, and 8 %, respectively, and stem 3 %. Leaf fresh mass, chlorophyll content, and CO2 exchange rate increased up to the third leaf. The total alkaloid content was highest in young actively growing leaves, which declined with age. Total 14C fixed and its content in ethanol soluble fraction increased up to the third leaf and then declined. The 14C content in primary metabolites such as sugars and organic acids was also highest in the 3rd leaf. The utilization of 14C assimilates into alkaloids was maximum in youngest leaf which declined with leaf age. Hence the capacity to synthesize alkaloids was highest in young growing leaves and metabolites from photosynthetic pathway were most efficiently utilized and incorporated into alkaloid biosynthetic pathway by young growing leaves. and N. K. Srivastava ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
197. UV-B radiation mediated alterations in the nitrate assimilation pathway of crop plants. 1.. Kinetic characteristics of nitrate reductase
- Creator:
- Balakumar, T., Selvakumar, V., Sathiameena, K., Murugu Ilanchezhian, C., and Paliwal, K.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- carotenoids, chlorophyll, fresh and dry mass, leaf area, root, shoot, and Vigna unguiculata
- Language:
- Multiple languages
- Description:
- The kinetics and other characteristics of nitrate reductase (NR, EC 1.6.6.1) in cowpea [Vigna unguiculata (L.) Walp.] seedlings irradiated with biologically effective UV-B radiation (280-320 nm, 3.2 W m-2 s-1) were recorded. The in vivo and in vitro NR activities were inhibited by 34 and 41 % under UV-B treatment, respectively. Both Vmax and Km for the substrate were enhanced by UV-B radiation. The Km for nitrate increased from 1.2 to 1.7 mM after the UV-B irradiation. The change in Km for NADH was from 0.12 to 0.17 mM. The increases in Km indicate that UV-B radiation seriously changes the topology of NR, particularly with respect to the nitrate and NADH binding sites. The rate of NR turnover indicates the extent of damage inflicted by UV-B radiation on the nitrate metabolism. The half-life (t1/2) of NR was reduced from 7 to 4 h in the UV-B treated seedlings. UV-B also inhibited the kinetics of nitrate uptake by plants: its Km increased from 0.08 to 0.12 mM. and T. Balakumar ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
198. Variation in photosynthetic rates and biomass productivity among four mulberry cultivars
- Creator:
- Chaitanya, K. V., Masilamani, S., Jutur, P. P., and Ramachandra Reddy, A.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- branches, chlorophyll, DCPIP photoreduction, glucose, Morus, ribulose-1,5-bisphosphate carboxylase, shoot, starch, sucrose, and sucrose phosphate synthase
- Language:
- Multiple languages
- Description:
- Among four mulberry (Morus alba L.) cultivars (K-2, MR-2, BC2-59, and S-13), highest net photosynthetic rate (PN) was observed in BC2-59 while the lowest rates were recorded with K-2. Significant differences among the four cultivars were found in leaf area, biomass production, activities of ribulose-1,5-bisphosphate carboxylase and sucrose phosphate synthase, and glucose and sucrose contents. The PN and the activities of photosynthetic enzymes in the four cultivars were significantly correlated with the growth and biomass production measured as leaf yield, total shoot mass, and aerial plant biomass. and K. V. Chaitanya ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
199. Variations in photosynthetic rate and associated parameters with age of oil palm leaves under irrigation
- Creator:
- Suresh, K. and Nagamani, C.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- area leaf mass, chlorophyll, Elaeis, leaf area, leaf dry mass, stomatal conductance, and transpiration rate
- Language:
- Multiple languages
- Description:
- Net photosynthetic rate (PN), transpiration rate (E), and stomatal conductance (gs) in an adult oil palm (Elaeis guineensis) canopy were highest in the 9th leaf and progressively declined with leaf age. Larger leaf area (LA) and leaf dry mass (LDM) were recorded in middle leaves. PN showed a significant positive correlation with gs and a negative relationship with leaf mass per area (ALM). The oil palm leaf remains photosynthetically active for a longer time in the canopy which contributes significantly to larger dry matter production in general and greater fresh fruit bunch yields in particular. and K. Suresh, C. Nagamani.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
200. Virus-induced changes in photosynthetic parameters and peroxidase isoenzyme contents in tomato (Solanum lycopersicum L.) plants
- Creator:
- Huseynova, I. M., Mirzayeva, S. M., Sultanova, N. F., Aliyeva, D. R., Mustafayev, N. Sh., and Aliyev, J. A.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- chlorofyl, karotenoidy, chlorophyll, carotenoids, tobamovirus, efektivita fotosystému II, tylakoidní membránové proteiny, peroxidace lipidů, peroxidázové aktivity, photosystem II efficiency, thylakoid membrane proteins, lipid peroxidation, peroxidase activity, 2, and 581
- Language:
- Multiple languages
- Description:
- Tomato samples were collected from the field of Absheron peninsula in Azerbaijan in order to evaluate the incidence of main Tobamoviruses. According to results of serological and molecular tests, Tomato mosaic virus (ToMV), Tobacco mosaic virus (TMV), and Pepper mild mottle virus (PMMoV) were detected as single and mixed infections (TMV + PMMoV; ToMV + PMMoV) in various tomato samples. It was found that Tobamovirus infection caused an increase in the content of malondialdehyde, alterations in the activities of peroxidase enzymes and quantitative and qualitative changes in their molecular isoforms. A comparison of thylakoid membrane polypeptides from virus-infected leaves indicated a decrease in the content of the thylakoid membrane polypeptides with molecular masses of 123, 55, 47, 33, 28-24, 17, and 15 kD. PSII efficiency and the content of chlorophylls (a and b) were significantly lower in the virus-infected leaves., I. M. Huseynova, S. M. Mirzayeva, N. F. Sultanova, D. R. Aliyeva, N. Sh. Mustafayev, J. A. Aliyev., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public