Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 4

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
Wild and cultivated varieties of Camellia oleifera Abel. were studied for the response of their photosynthetic apparatus to Al toxicity and low-P stress in pot experiments with medium of acidic red soil. The effect was measured using physiological processes (growth, photosynthesis, chlorophyll a fluorescence), and pigment contents. The results showed that Al toxicity and low-P stress affected the seedlings’ growth and leaves’ photosynthesis, and the differences could be found between the two varieties. Lime plus P fertilizer treatment led to higher increase in the net photosynthetic rate (Pn) in the cultivar than in the wild variety. Pn increase was positively related to the increase of stomatal conductance (gs) and negatively correlated to intercellular CO₂ concentration (Ci) in both varieties. The maximum PSII quantum yield (Fv/Fm), the efficiency of excitation energy capture by open PSII reaction centers (Fv’/Fm’), the photochemical quenching (qP) and the efficiency of open PSII centers (ΦPSII) significantly increased almost in all the treatment groups of both varieties, with the exception of an insignificant change in qP value for P₁Al₁ group of cultivar. The insensitive qP and lower Pn for cultivar indicate a higher photosynthetic efficiency for the wild variety, though the ΦPSII was not significant between the two varieties. The pigment contents of oil tea seedlings under treatments changed significantly when lime and P were added, especially the Car/Chl ratio, suggesting carotenoid plays the role of photoprotection under high-Al and low-P stresses.
Mosses are the pioneer and the first green land plants developed during the evolutionary process, they play an important role in the development of soil, biogeochemical cycling and facilitating plant colonization. Although species richness, composition, diversity and cover of moss communities vary, they grow well almost in all forests. Why mosses can grow in different conditions? What are the adaptive strategies of mosses in different forests along primary succession sequences? It is not still completely clear. In order to answer these questions, nutrient and carbohydrate accumulation in mosses were tested along the primary succession following deglaciation of Hailuogou glacier, Gongga Mountain, China. Nitrogen (N), phosphorus (P), potassium (K) content, total organic carbon (TOC), soluble sugar and starch accumulated in the dominant moss species were determined and compared. TOC increased insignificantly with forest age. N, P, K contents in mosses were significantly higher in forests with dense shrubs, where N content was seperately 1.69% in A. hookeri and 1.35% in P. schreberi in 30 yr aged forest, P content in 30 yr and 52 yr aged forest was seperately 0.022% and 0.020% in A. hookeri and 0.020% and 0.017% in P. schreberi, and K content in 30 yr and 52 yr aged forest was seperately 0.570% and 0.553% in A. hookeri and 0.490% and 0.493% in P. schreberi. Soluble sugar was higher in the early stage of succession, but the opposite was observed for starch and nonstructure carbohydrate content, which was lower in early successional stage. Mosses adopted different adaptive strategies in different aged forests along receding glacier, in which starch and N, P, K contents were key for adaptiation. That is, mosses accumulated much more starch in the severe environment of early succession stage. In more favourable environment, N, P, K was found to be accumulated for plant growth.
In the present study we determined whether CpG motifs could be used as an immune adjuvant for the Omp-1 DNA vaccine against Chlamydophila psittaci, based on the major outer membrane protein (MOMP), to induce the protection in specific pathogen free chickens against an intranasal challenge. Six sequences of phosphorothioate-CpG oligodeoxynucleotides (CpG ODNs) with strong immunostimulatory activity were designed to be examined. The CpG ODN with three GTCGTT repeats significantly promoted splenic lymphocyte proliferation and increased macrophage nitric oxide in a in vitro study. Birds vaccinated with CpG ODN and pcDNA3.1:MOMP induced moderate antibody response and higher lymphoproliferative stimulation while chickens primed-boosted with DNA alone did not. Furthermore, DNA vaccine plus CpG ODN accelerated chlamydial clearance in the spleen and lungs, and decreased inflammatory cellular infiltration. All above evidences show that CpG ODN can be used as an effective adjuvant with a DNA vaccine and this immunisation protocol resulted in an enhanced clearance of Chlamydophila psittaci.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.