以两种菊属野生植物‘菊花脑’(Dendranthema nankingense)和‘乙立寒菊’(D.indicum var. maruyama-num)幼苗为材料,通过Hogland营养液水培试验研究了120和180mmol·LNaCl的渐进和非渐进胁迫处理对幼苗叶片受害程度及植株生物量、...以两种菊属野生植物‘菊花脑’(Dendranthema nankingense)和‘乙立寒菊’(D.indicum var. maruyama-num)幼苗为材料,通过Hogland营养液水培试验研究了120和180mmol·LNaCl的渐进和非渐进胁迫处理对幼苗叶片受害程度及植株生物量、根系活力、叶片叶绿素含量、相对电导率和丙二醛含量的影响,以探讨它们对盐冲击的生理响应规律。结果显示:(1)在两种浓度盐胁迫下,两种菊属植物的整株鲜重、根系活力、叶片叶绿素含量大多显著下降,而同期的叶片丙二醛(MDA)含量、相对电导率显著增加;渐进盐胁迫下材料受害程度均轻于非渐进胁迫;盐胁迫浓度越大,各指标变化幅度越大,且两种胁迫方式下各指标的差异亦越大;(2)‘菊花脑’对盐胁迫敏感,而‘乙立寒菊’对盐胁迫的耐性较强;相同盐胁迫浓度下,非渐进胁迫与渐进胁迫间的差异在盐敏感材料上表现较明显。研究表明,两种菊属植物均存在盐冲击现象,并以耐盐性弱的材料表现更加突出,且高盐胁迫下植物所受的冲击伤害更明显。展开更多
The unicellular halotolerant alga Dunaliella salina had the ability to oxidize NADH and reduce Fe(CN)63-. The redox reactions were to some extent stimulated by slight hyperosmotic shock (2.0 mol/L → 2.6 mol/L NaCl), ...The unicellular halotolerant alga Dunaliella salina had the ability to oxidize NADH and reduce Fe(CN)63-. The redox reactions were to some extent stimulated by slight hyperosmotic shock (2.0 mol/L → 2.6 mol/L NaCl), butmarkably inhibited by abrupt hyperosmotic shock (2.0mol/L → 3.5 mol/L NaCl) and hypoosmotic shock (2.0mol/L → 1.0 mol/L NaCl; 2.0 mol/L→0.67 mol/L NaCl).With the adaptation of algal cells to osmotic shock by accumulating or degrading intracellular glycerol, the plasmalemma redox activities were also restored. The O2 uptake stimulated by NADH could be promoted by FA and SHAM. Hypoosmotic shock increases the basal respiration rate of alga cells, but weakened the stimulating effects of NADH, FA and SHAM on O2 uptake. On the other hand, hyperosmotic shock reduced the basal respiration rate, but relatively enhanced the above effects of NADH, FA and SHAM. H+ extrusion of alga cells was inhibited by NADH and stimulated by Fe(CN)63- Vanadate and DES could inhibit H+ efflux, but had little effect in the presence of NADH and Fe(CN)63-. Both hyperand hypoosmotic shock stimulated H+ extrusion. This effect could be totally inhibited by vanadate and DES, but almost unaffected by 8-hydroxyquinoline. It was suggested that H+-ATPase probably played a more important role in H+ extrusion and osmoregulation under the conditions of osmotic shock.展开更多
Sinorhizobium fredii RT19, a strain of free- living bacteria, was subjected to salt shock and its protein expression profiles were analyzed by differential display proteome approaches. The results of separation by two...Sinorhizobium fredii RT19, a strain of free- living bacteria, was subjected to salt shock and its protein expression profiles were analyzed by differential display proteome approaches. The results of separation by two-dimensional polyacrylamide gel electrophoresis (2D PAGE) showed that the number of resolved proteins was 481, 465 and 424, corresponding to salt-free control, 5 and 50 min 1 mol/L salt treatment, respectively. Among the resolved proteins, 82 in total had altered expression in response to salt-shock stress. 26 out of the 82 proteins were induced and 23 were completely inhibited, while 12 were up-regulated and 21 down-regulated in response to salt shock. In addition, the appearance of differentially displayed proteins responding to different salt shock periods is also reported. The identity of the 26 induced proteins was revealed by matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS) followed by database searching. Among them, 20 were assigned to proteins with known functions. Their roles in response to salt shock stress are discussed.展开更多
文摘以两种菊属野生植物‘菊花脑’(Dendranthema nankingense)和‘乙立寒菊’(D.indicum var. maruyama-num)幼苗为材料,通过Hogland营养液水培试验研究了120和180mmol·LNaCl的渐进和非渐进胁迫处理对幼苗叶片受害程度及植株生物量、根系活力、叶片叶绿素含量、相对电导率和丙二醛含量的影响,以探讨它们对盐冲击的生理响应规律。结果显示:(1)在两种浓度盐胁迫下,两种菊属植物的整株鲜重、根系活力、叶片叶绿素含量大多显著下降,而同期的叶片丙二醛(MDA)含量、相对电导率显著增加;渐进盐胁迫下材料受害程度均轻于非渐进胁迫;盐胁迫浓度越大,各指标变化幅度越大,且两种胁迫方式下各指标的差异亦越大;(2)‘菊花脑’对盐胁迫敏感,而‘乙立寒菊’对盐胁迫的耐性较强;相同盐胁迫浓度下,非渐进胁迫与渐进胁迫间的差异在盐敏感材料上表现较明显。研究表明,两种菊属植物均存在盐冲击现象,并以耐盐性弱的材料表现更加突出,且高盐胁迫下植物所受的冲击伤害更明显。
文摘The unicellular halotolerant alga Dunaliella salina had the ability to oxidize NADH and reduce Fe(CN)63-. The redox reactions were to some extent stimulated by slight hyperosmotic shock (2.0 mol/L → 2.6 mol/L NaCl), butmarkably inhibited by abrupt hyperosmotic shock (2.0mol/L → 3.5 mol/L NaCl) and hypoosmotic shock (2.0mol/L → 1.0 mol/L NaCl; 2.0 mol/L→0.67 mol/L NaCl).With the adaptation of algal cells to osmotic shock by accumulating or degrading intracellular glycerol, the plasmalemma redox activities were also restored. The O2 uptake stimulated by NADH could be promoted by FA and SHAM. Hypoosmotic shock increases the basal respiration rate of alga cells, but weakened the stimulating effects of NADH, FA and SHAM on O2 uptake. On the other hand, hyperosmotic shock reduced the basal respiration rate, but relatively enhanced the above effects of NADH, FA and SHAM. H+ extrusion of alga cells was inhibited by NADH and stimulated by Fe(CN)63- Vanadate and DES could inhibit H+ efflux, but had little effect in the presence of NADH and Fe(CN)63-. Both hyperand hypoosmotic shock stimulated H+ extrusion. This effect could be totally inhibited by vanadate and DES, but almost unaffected by 8-hydroxyquinoline. It was suggested that H+-ATPase probably played a more important role in H+ extrusion and osmoregulation under the conditions of osmotic shock.
文摘Sinorhizobium fredii RT19, a strain of free- living bacteria, was subjected to salt shock and its protein expression profiles were analyzed by differential display proteome approaches. The results of separation by two-dimensional polyacrylamide gel electrophoresis (2D PAGE) showed that the number of resolved proteins was 481, 465 and 424, corresponding to salt-free control, 5 and 50 min 1 mol/L salt treatment, respectively. Among the resolved proteins, 82 in total had altered expression in response to salt-shock stress. 26 out of the 82 proteins were induced and 23 were completely inhibited, while 12 were up-regulated and 21 down-regulated in response to salt shock. In addition, the appearance of differentially displayed proteins responding to different salt shock periods is also reported. The identity of the 26 induced proteins was revealed by matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS) followed by database searching. Among them, 20 were assigned to proteins with known functions. Their roles in response to salt shock stress are discussed.
