Maintenance of ion homeostasis, particularly the regulation of K+ and Na+ uptake, is important for all plants to adapt to salinity. Observations on ionic response to salinity and net fluxes of K+, Na+ in the root exhibited by plants during salt stress have highlighted the need for further investigation. The objectives of this study were to compare salt adaptation of two Chinese Iris (Iris lactea Pall. var. chinensis (Fisch.) Koidz.) populations, and to improve understanding of adaptation to salinity exhibited by plants. Plants used in this study were grown from seeds collected in the Xinjiang Uygur Autonomous Region (Xj) and Beijing Municipality (Bj), China. Hydroponically-grown seedlings of the two populations were supplied with nutrient solutions containing 0.1 (control) and 140 mmol·L-1 NaCl. After 12 days, plants were harvested for determination of relative growth rate and K+, Na+ concentrations. Net fluxes of K+, Na+ from the apex and along the root axis to 10.8 mm were measured using non-invasive micro-test technique. With 140 mmol·L-1 NaCl treatment, shoots for population Xj had larger relative growth rate and higher K+ concentration than shoots for population Bj. However, the Na+ concentrations in both shoots and roots were lower for Xj than those for Bj. There was a lower net efflux of K+ found in population Xj than by Bj in the mature zone (approximately 2.4-10.8 mm from root tip). However, no difference in the efflux of Na+ between the populations was obtained. Population Xj of I. lactea continued to grow normally under NaCl stress, and maintained a higher K+/Na+ ratio in the shoots. These traits, which were associated with lower K+ leakage, help population Xj adapt to saline environments. 相似文献
Hypocholesterolemic and hypoglycemic activities of Coptis chinensis franch inflorescence (Coptis inflorescence) were studied using animal models. Serum total and LDL cholesterol of rats fed a diet containing 1% cholesterol and 0.5% cholic acid increased, as compared with those of rats fed a normal diet. The level of total and LDL cholesterol were reduced markedly in a dose dependent manner, in rats given Coptis inflorescence extract orally at doses of 0.25, 0.5 g/kg.day for 4 weeks. In diabetic rats induced by alloxan, Coptis inflorescence extract showed a significant (p < 0.05) blood sugar lowering activity at all experimented doses (0.125, 0.25 and 0.5 g/kg.day). The highest reduction of blood sugar was about 58% when the rats were given Coptis inflorescence extract orally at a dose of 0.5 g/kg.day for 3 weeks. The 100 g dried water extract of Coptis inflorescence contained 8.11 g total alkaloid, 3.34 g berberin, 1.08 g palmatine and 0.66 g jatrorrhizine, which had long been identified as active compounds in Coptis chinensis franch root (Coptis root). Thus, the results suggest that Coptis inflorescence would be effective in the prevention and management of coronary artery disease by lowering serum cholesterol and blood sugar. 相似文献