physiological and biochemical responses to salt stress in the mangrove

... salinity, water stress, stomatal closure, decrease in intracellular CO 2 , and decrease in photosynthesis. The linear relation between photosyn- thesis and transpiration rates, the latter being ... method of Elstner and Heupel (1976) and Ganschow and Schike (1969), respectively, and these results were then normalized to total protein in the sample. To investigate the effect of salt on enzyme ... in the presence of xanthineoxidase. A steep increase in the activity of SOD began immediately following the transfer of the plant grown in water into a 500mM NaCl solution (Fig. 5). The SOD and...

Ngày tải lên: 06/07/2014, 02:20

... in Katherine seedlings (Fig. 4), and the prov- enances also differed in stress- induced changes in the partitioning of dry matter into roots, stems and leaves (Fig. 5). Stressed ... differences between provenances in the production of hairs on the collar of ger- minating seedlings (Fig. 1 which bind the III seedling firmly to the soil and assist early water ... in the environment in which these provenances occur naturally (Gib- son and Bachelard, 1987). In this study, the effects of water stress on the initial establishment and...

Ngày tải lên: 09/08/2014, 04:20

... species may be able to explain these differences in drought-induced sensitivity to photoinhibi- tion. Still the higher tolerance to photoinhi- bition in Q cerris at a similar ... s -1 . Then, the leaf disk was exposed to a PFD of 1750 μmol m -2 s -1 for 135 min and finally put in the dark for 45 min to determine long-term changes in maximal ... stress, high light and species responses need fur- ther analysis to elucidate such differential responses. It appears that the drought- induced increase in sensitivity to...

Ngày tải lên: 08/08/2014, 19:21

Ngày tải lên: 13/08/2014, 13:20

... SASSETA and three companies within each of the two sectors. Chapter 8, the final chapter, presents all the conclusions of the findings from the two studies conducted in both sectors and then makes ... epidemic to their core business. Thus, there is a need to conduct assessments of the impacts of HIV/AIDS and responses thereto by companies. Obtaining such information would inform the concerned ... www.hsrcpress.ac.za xxv  Main findings of Studies 2A and 2B in the legal services sector Employer perceptions of impact of HIV/AIDS on business The following main findings emerged: HIV/AIDS was not regarded as a business...

Ngày tải lên: 22/03/2014, 18:20

... lower in N. nitida and along with the photochemical efficiency in the dark (Fv/Fm) they declined in both species. Non-photochemical quenching (NPQ) increased slowly in N. dombeyi along with the gradual ... drought intensity [6] the same PPFD became probably saturating at a Ψ m lower than −2.5 MPa, producing the increase of NPQ in N. dombeyi and the concomitant decrease in Fv/Fm, ∆F/Fm  and qP. In conclusion, ... higher WUE and photosynthesis under severe drought stress. Acknowledgements: We thank the staff of the Instituto de Botánica of the Universidad Austral de Chile for their logistic support and maintenance...

Ngày tải lên: 07/08/2014, 16:21

Ngày tải lên: 13/11/2014, 09:42

... partners in the phenomenon. In the zooxanthella, heat stress has been demonstrated to reduce the photosynthetic rate by decreasing the effi- ciency of the photosystem II [4–6] and ⁄ or by causing damage ... degeneration [8,9,53,56] and ⁄ or gastrodermal detachment [7,52,57]. Nevertheless, independently of the resulting effect of the thermal stress, all mechanisms point to the involve- ment of oxidative stress in the ... indicate the His and Cys residues of the putative active site located in the large subunit. The six a -helix components of the prodomain are underlined. Apoptosis and oxidative stress in bleaching...

Ngày tải lên: 30/03/2014, 10:20

... were examined for 3 min. Each point represents the mean of six individual salt glands, and the bars represent the SE of the mean. The inserts show mean Na + fluxes and SE within the measuring periods. Columns ... was used in other NO-related experiments. To clarify the role of NO in inducing high Na + secretion rate and maintaining low Na + to K + ratio in leaves, specific NO synthesis inhibitors (N-nitro-L-arginine ... enhanced the Na + secretion rate, Na + percentage and Na + to K + ratio in the region of the salt gland, thus maintaining intracellular ionic homeostasis in the leaves, whereas inhibition of NO synthesis...

Ngày tải lên: 06/07/2014, 02:20

... tended to rise with increase in salinity. Total soluble sugar content in leaves of Sa and Sc increased by a larger margin in high salin- ity (> 30) than in low salinity (< 30). For Rs, total ... salinity. Net photosynthesis rate and stomata conductance of Sa and Sc decreased as salinity in the culture medium rose from 0 to 40 (Figs. 1 and 2). When salinity was above 15, the decreasing ... photosynthesis rate of Rs increased appreciably in the beginning (< 20) and decreased subse- quently (> 20), but the changes tended to be minor. Stomata conductance of Rs increased to...

Ngày tải lên: 06/07/2014, 02:20

Ngày tải lên: 11/08/2014, 18:20

Ngày tải lên: 11/08/2014, 11:21

... weak among the stakeholders. Inhibiting the improvement is lack of monitoring and evaluation on the ground which feeds into learning and adaptation. Public awareness about the institutional ... existing capacities, success and failures in performance of institutions, explaining possibilities and constraints for institutional capacity building and performance, and identifying and contrasting ... countries allows IFA to make a step further in finding answers to the question of how to increase domestic institutional capacities and enhance their practices in floods risk reduction towards greater...

Ngày tải lên: 22/10/2013, 10:15

... system, thereby changing the activity of the chloroplast. To what extent the closure of the stoma affects the photosynthesis rate depends on the partial pressure of CO 2 in the lamina. However ... salinity was greater than 40. No changes were observed in the MDA content of roots in the three mangrove species. The adaptabilities of Sa and Sc to salt tolerance were limited. The more salt tolerant ... tended to rise with increase in salinity. Total soluble sugar content in leaves of Sa and Sc increased by a larger margin in high salin- ity (> 30) than in low salinity (< 30). For Rs, total...

Ngày tải lên: 05/07/2014, 23:21

... removed from storage, thawed, acclimated to light and returned to the containers as described above. These seedlings are referred to below as dormant seedlings. Seedling morphology at the beginning of the ... sensor). The frame was removed at 0500 h the next morning and 10 seedlings from both groups (dormant + growing) were trans- ferred to the laboratory in a cool bag. In the laboratory, the seedling shoots ... seedlings were exposed to drought after planting, root egress of growing seedlings showed a considerable decline. On the other hand, root egress in dormant seedlings was rather insensitive to drought,...

Ngày tải lên: 08/08/2014, 00:21

... directed to repair processes. However, after 85 days, the NR activity in the seedlings was lower and decreased with increasing O 3 . At that time in the season and with increasing oxidative stress, ... photorespiration to oxidative stress and contradictory results have been observed. Dizengremel and Pétrini [9] observed an increase in the photorespiration pathway in plants under pollutant stress. ... cases, the slope and the intercept of the regressions were not different from zero (Tabs. I, II and III). Therefore, we pooled the data from both light intensities for the analysis of the effect of the...

Ngày tải lên: 08/08/2014, 00:22

... 1.5–2.5 m from the ground in the evening hours of the day previous to the day of the measurement, sealed in a polythene bag to reduce evapo- rative loss of water and taken to the laboratory. Here ... of water stress and could therefore increase the chances of this species to compete with the other treeline species for the colonisation of the alpine areas rendered suitable to seedling establishment ... decreasing to their mini- mum at the beginning of August (day 214). The values obtained on day 213 for P.cembra were slightly higher. The relative water content at turgor loss point (RTLP) and the...

Ngày tải lên: 08/08/2014, 14:22

... flats in the floodplain (Hodges and Switzer, 1979; Tanner, 1986). These sites are frequently flooded, can remain saturated into the growing season, and exhibit poor internal ... resistance to root hypoxia. The hypothesis was tested on seedlings during the establishment phase in Experiment 1, and it was tested on seedlings late in their first growing season ... flood- induced stomatal and photosynthetic responses of three bottomland tree species. For Sci 32, 914- 923 Ponnamperuma FN (1984) Effects of flooding on soils. In: Flooding and Plant...

Ngày tải lên: 08/08/2014, 18:21

... related to pollinic enzymes involved in pollen tube metabo- lism, such as ¡3-galactosidase. Its activity could be the final result of a series of inter- actions started by initial ... the compat- ible pollen tube, shifting from an auto- trophic to a heterotropic type of nutrition. Biochemical studies focused on pollinic and stigmatic proteins, known to ... be in- volved in male-female interactions (Gaude and Dumas, 1987). After silver nitrate staining, qualitative and quantita- tive differences could be observed, related to the...

Ngày tải lên: 09/08/2014, 04:20

Ngày tải lên: 09/08/2014, 04:20