首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到18条相似文献,搜索用时 187 毫秒
1.
短日照对休眠诱导期油桃花芽两条电子传递途径的调控   总被引:2,自引:0,他引:2  
Li DM  Zhang HS  Tan QP  Li L  Yu Q  Gao DS 《应用生态学报》2011,22(11):2849-2854
以油桃品种“曙光”为试材,采用呼吸抑制剂法研究了短日照处理下花芽在休眠诱导期两条电子传递途径的发生和运行情况.结果表明:花芽总呼吸速率(Vt)和细胞色素电子传递途径呼吸速率(ρ'Vcyt)均呈双峰曲线变化,短日照可同步诱导两者的一次峰前移、二次峰后延,抑制ρ’Vcyt,但对Vt无显著影响.交替途径容量(Valt)和实际运行活性(ρValt)亦呈双峰曲线,两者基本同步变化,短日照可以显著诱导Valt和ρValt的前期高峰期提前,提高Valt和ρValt,对后期高峰期无明显作用.细胞色素电子传递途径呼吸速率下降和交替途径呼吸速率上升是油桃花芽休眠诱导期的重要特点.从两条电子传递途径的呼吸速率对总呼吸速率的贡献率来看,细胞色素电子传递途径仍是主要电子传递途径,交替途径起辅助与分流作用.  相似文献   

2.
表面活性剂对香石竹切花保鲜效果的研究   总被引:1,自引:0,他引:1  
目的:解决香石竹采后运输和瓶插过程中花朵衰老问题.方法:研究表面活性剂对香石竹切花保鲜效果,测定瓶插期间的花枝鲜重、花朵直径、SOD活性.结果:由蔗糖25mg/L+柠檬酸200mg/L+8-HQ 200mg/L+吐温0.01%组成的保鲜剂配方,比对照能延长切花瓶插寿命11.4d.结论:在保鲜剂配方中可以使用表面活性剂(如吐温)等物质,其浓度控制在0.01%范围内.  相似文献   

3.
KCN和NaN3预处理对烟草愈伤组织抗氰呼吸的影响   总被引:3,自引:0,他引:3  
用0.5 m m ol/L KCN 或0.01 m m ol/L NaN3 预处理继代培养25 d 的“甘肃黄花烟草”(Nicotiana rustica L. cv. Gansu yellow flow er)愈伤组织对其呼吸作用有明显的影响。KCN 和NaN3 预处理12 h 可分别使愈伤组织的总呼吸速率下降12% 和17% ,细胞色素途径的实际运行量分别下降22% 和28% ;抗氰交替途径在最大容量(Valt)基本不变的情况下,实际运行量(ρ·Valt)不但未随总呼吸速率和细胞色素途径运行量的下降而降低,反而还略有上升。结果导致细胞色素途径对总呼吸的贡献下降而抗氰交替途径对总呼吸的贡献上升。KCN 预处理24 h,细胞色素途径的实际运行量虽略有回升,但仍低于对照;NaN3 预处理24 h 则使细胞色素途径运行继续下降而交替途径运行持续上升。上述结果表明,在继代培养的烟草愈伤组织中,当细胞色素主路途径被部分抑制后交替途径的电子流量明显加强,从而起着一种补偿作用  相似文献   

4.
水杨酸对低温胁迫香蕉幼苗呼吸作用的影响   总被引:1,自引:0,他引:1  
探讨了水杨酸 (salicylicacid ,SA)对低温胁迫香蕉幼苗叶片呼吸作用的影响。在常温下用 0 .5mmol/LSA水溶液处理香蕉幼苗 ,能明显提高香蕉幼苗的抗氰呼吸和细胞色素呼吸 ,增加总呼吸量 ,提高产热量 ;在随后 7℃低温胁迫与常温恢复期间SA预处理 ,能抑制总呼吸速率的下降 ,这种对总呼吸下降的抑制与此时细胞色素途径维持在较高的水平有关 ,而与抗氰呼吸无关。此时也未检测到SA预处理植株叶片产热量增加的现象  相似文献   

5.
保鲜剂对香石竹切花保鲜的生理效应   总被引:15,自引:1,他引:15  
经由蔗糖、8-羟基喹啉和醋酸银组成的保鲜剂处理的香石竹切花瓶插寿命延长,吸水能力提高,乙烯生成受抑,乙烯释放高峰和呼吸跃变的出现推迟,吸水率与呼吸强度以及鲜重与花径之间都呈极显著相关。切花在乙烯释放高峰和呼吸跃变时,花瓣电导率迅速提高。保鲜剂抑制花瓣电导率的上升幅度。  相似文献   

6.
本文以不含叶绿体的烟草BY-2悬浮细胞系为实验材料,研究了CuCl2胁迫对BY-2细胞呼吸速率、呼吸途径以及细胞内H2O2和ATP含量的影响。结果表明:0.5mmol·L-1CuCl2胁迫明显导致了烟草BY-2细胞的死亡,引起了胞内H2O2爆发和ATP含量下降,严重抑制了BY-2细胞的总呼吸和交替氧化酶途径(alternative oxidase pathway,AOX)。此外,CuCl2对BY-2细胞的线粒体电子传递具有即时的抑制作用。加入外源腺苷(ATP合成的底物)显著抑制了CuCl2胁迫引起的ATP损耗,并阻止了细胞死亡。上述结果表明CuCl2胁迫导致的ATP损耗在CuCl2诱导烟草BY-2细胞死亡过程中起重要的作用。  相似文献   

7.
本文以不含叶绿体的烟草BY-2悬浮细胞系为实验材料,研究了CuCl2胁迫对BY-2细胞呼吸速率、呼吸途径以及细胞内H2O2和ATP含量的影响。结果表明:0.5mmol·L-1CuCl2胁迫明显导致了烟草BY-2细胞的死亡,引起了胞内H2O2爆发和ATP含量下降,严重抑制了BY-2细胞的总呼吸和交替氧化酶途径(alternative oxidase pathway,AOX)。此外,CuCl2对BY-2细胞的线粒体电子传递具有即时的抑制作用。加入外源腺苷(ATP合成的底物)显著抑制了CuCl2胁迫引起的ATP损耗,并阻止了细胞死亡。上述结果表明CuCl2胁迫导致的ATP损耗在CuCl2诱导烟草BY-2细胞死亡过程中起重要的作用。  相似文献   

8.
将杨树叶片置于持续的光照下增加了其光合速率和异戊二烯的释放水平。持续的光照也诱导了总呼吸、细胞色素途径和交替呼吸途径容量的增加。用细胞色素途径和交替呼吸途径的抑制剂氰化钾和水杨基氧肟酸降低了光照下叶片的光合速率和异戊二烯的释放水平,也导致了光系统Ⅱ的光合效率和光化学淬灭系数的降低。这些结果表明了呼吸作用可能有助于光合作用的正常运行和光照下植物异戊二烯的释放。  相似文献   

9.
实验结果表明:烟划愈伤组织在生长和衰老期间,总呼吸速率(Vt)分别在11d和19d出现2次呼吸跃升;细胞色素途径的运行(ρ'Vcyt)与Vt的变化几乎一致,表明细胞色素途径仍组织主要的电子传递途径;交替途径容量(Valt)及其与Vt的比值(Valt/Vt):在15d前不断上升,而在15-19d之间处于稳定水平后下降。交替途径运行(ρValt)及其对Vt的贡献(ρValt/Vt)却与Valt变化趋势  相似文献   

10.
孙聪  白杨  李连国  郭金丽 《西北植物学报》2019,39(10):1805-1811
该试验以草莓(Fragaria ananassa Duch.)品种‘红颜’果实为试材,采用水杨基氧肟酸(SHAM)抑制线粒体交替呼吸途径,使细胞色素途径单独运行,并用电子传递与氧化磷酸化偶联促进剂[二磷酸腺苷(ADP)、琥珀酸钠(C_4H_4Na_2O_4)]和抑制剂[2,4-二硝基苯酚(DNP)、原钒酸钠溶液(NaVO_4)]对线粒体提取液进行处理,对比分析在促进和抑制呼吸代谢情况下,草莓果实线粒体呼吸代谢与超微弱发光(UWL)的变化及二者之间的关系。结果显示:(1)草莓果实线粒体经促进剂处理后,呼吸代谢关键酶琥珀酸脱氢酶(SDH)、细胞色素氧化酶(COX)、ATP合酶(H~+-ATPase)活性以及呼吸速率、三磷酸腺苷(ATP)含量均随着促进剂浓度的增加而增加,UWL强度亦增强,且各浓度下的呼吸代谢指标和UWL强度均高于对照;经抑制剂处理后,以上呼吸代谢各指标及UWL强度的变化与促进剂处理相反,且均低于对照。(2)各促进剂、抑制剂处理条件下,草莓果实线粒体呼吸代谢各指标均与其UWL强度呈正相关。研究表明,草莓果实线粒体UWL强度随着呼吸代谢的变化而变化;促进剂促进了呼吸代谢,导致UWL强度增加,而抑制剂却抑制了呼吸代谢,导致UWL强度减弱;线粒体是UWL产生的细胞器之一,线粒体呼吸代谢过程中激发了UWL。  相似文献   

11.
The effects of KCN (0.5mmol/L) and NaN3 (0.01 mmol/L) pretreatment on the operation of the alternative pathway in subcultured tobacco (Nicotiana rustica L. cv. Gansu yellow flower) callus were analyzed. After treatment with KCN and NaN3 for 12 h, the total respiration rate (Vt) decreased by 12% and 17%, whereas oxygen consuption by the cytochrome pathway decreased by 22% and 28% respectively. The capacity of the alternative pathway (Valt) remained constant, while the activity of the alternative pathway (ρ· Valt ) inreased slightly. This changing pattern led to a declined contribution of the cytochrome pathway to the total respiration rate and an increased activity of the alternative pathway. Treatment with KCN for 24 h brought about a slight rise of oxygen consumption by the cytochrome pathway as compared with that in callus treated for 12 h, but the oxygen consumption was still lower than that in the untreated callus. Treatment with NaN3 for 24 h resulted in a profound decrease of the cytochrome pathway operation and a continuing increase of the alternative pathway operation. These data indicated that the enhanced operation of the alternative pathway played a compensatory role to the total respiration when the cytochrome pathway was partially inhibited in tobacco callus.  相似文献   

12.
The Kok effect refers to the progressive light-induced inhibition of dark respiration at low light intensities, which saturates around the light compensation point. This appears as a sudden break around the light compensation point in the plot of photosynthesis versus light intensity. The magnitude of the break can be considered as a measure of the Kok effect. In the present work, the importance of different components of dark respiration during the Kok effect was investigated by using low concentrations of mitochondrial inhibitors in leaf discs of pea ( Pisum sativum L. cv. Azad P1). The effects of glucose (stimulates respiration) and 0.8 M sorbitol (imposes osmotic stress and inhibits photosynthesis) were also studied for comparison. The magnitude of the break decreased significantly in the presence of antimycin A or oligomycin (inhibitors of cytochrome pathway of mitochondrial electron transport and ATP synthase, respectively). In contrast, there was no significant change with salicylhydroxamic acid (SHAM; an inhibitor of alternative pathway of mitochondrial electron transport). The magnitude of the break increased significantly with glucose, and decreased on exposure to osmotic stress. Our results suggest that the Kok effect (inhibition of dark respiration in light) is modulated by inhibitors of cytochrome pathway and ATP synthesis, but not that of the alternative pathway.  相似文献   

13.
继代培养期间的烟草愈伤组织总呼吸速率分别在第11天和第19天出现两次跃升,同时抗氰呼吸的发生与运行逐渐加强,在两呼吸高峰之间达到极大值,随后则逐渐下降,但愈伤组织的电子传递仍以细胞色素途径为主.通过对愈伤组织衰老过程中活性氧代谢变化分析,发现抗氰呼吸发生与H  相似文献   

14.
杜氏盐藻在适应外界盐浓度变化的过程中,甘油是其主要的渗透调节物质。低渗处理提高藻细胞的呼吸速率60%以上;高渗处理对呼吸无明显影响,但大大刺激光合放氧速率。呼吸链的细胞色素电子传递链抑制剂KCN和交替氧化酶抑制剂SHAM对杜氏藻渗透调节过程中的呼吸.胞内甘油、ATP、淀粉会量的变化有不同的抑制效果。低渗情况下,胞内甘油转化为淀粉,所需能量由正常呼吸链和交替氧化酶途径同时提供;高渗情况下.淀粉则降解为甘油,光下甘油合成的能量主要由光合电子链提供,暗中则由正常呼吸链提供。  相似文献   

15.
In suspension cells of NT1 tobacco (Nicotiana tabacum L. cv bright yellow), inhibition of the cytochrome pathway of respiration with antimycin A induced a large increase in the capacity of the alternative pathway over a period of approximately 12 h, as confirmed in both whole cells and isolated mitochondria. The increase in alternative pathway capacity required de novo RNA and protein synthesis and correlated closely with the increase of a 35-kD alternative oxidase protein. When the cytochrome pathway of intact cells was inhibited by antimycin A, respiration proceeded exclusively through the alternative pathway, reached rates significantly higher than before antimycin A addition, and was not stimulated by p-trifluoromethoxycarbonylcyanide (FCCP). When inhibition of the cytochrome pathway was relieved, alternative pathway capacity and the level of the 35-kD alternative oxidase protein declined. Respiration rate also declined and could once again be stimulated by FCCP. These observations show that the capacities of the mitochondrial electron transport pathways can be regulated in a coordinate fashion.  相似文献   

16.
真菌是现代微生物发酵产业的主力军之一。交替呼吸途径(Alternative respiration pathway,ARP),以其非磷酸化电子传递途径,起到了能量溢流(Energy overflow)的作用,调节细胞能量代谢,平衡碳代谢和电子传递,有利于代谢产物的积累。此外,交替呼吸对真菌的抗逆反应和条件致病菌的生理作用也都具有非常重要的影响。交替氧化酶(Alternative oxidase,AOX)是线粒体中交替呼吸途径的末端氧化酶,广泛存在于高等植物及部分真菌和藻类中。由于交替氧化酶对水杨氧肟酸(Salicylhydroxamic acid,SHAM)敏感而对细胞色素呼吸抑制剂氰化物不敏感,交替氧化酶AOX介导的交替呼吸途径又被称为抗氰呼吸途径(Cyanide-resistant respiration,CRR)。近年来,研究交替呼吸途径和交替氧化酶已成为细胞呼吸代谢领域的热门课题。本文主要对真菌交替呼吸途径和交替氧化酶的结构与其在工业真菌体内功能的最新研究进展作一简要的综述。  相似文献   

17.
The role of mitochondrial respiration in optimizing photosynthesis was assessed in mesophyll protoplasts of pea ( Pisum sativum L., cv. Arkel) by using low concentrations of oligomycin (an inhibitor of oxidative phosphorylation), antimycin A (inhibits cytochrome pathway of electron transport) and salicylhydroxamic acid (SHAM, an inhibitor of alternative oxidase). All three compounds decreased the rate of photosynthetic O2 evolution in mesophyll protoplasts, but did not affect chloroplast photosynthesis. The inhibition of photosynthesis by these mitochondrial inhibitors was stronger at optimal CO2 (1.0 m M NaHCO3) than that at limiting CO2 (0.1 m M NaHCO3). We conclude that mitochondrial metabolism through both cytochrome and alternative pathways is essential for optimizing photosynthesis at limiting as well as at optimal CO2. The ratios of ATP to ADP in whole protoplast extracts were hardly affected, despite the marked decrease in their photosynthetic rates by SHAM. Similarly, the decrease in the ATP/ADP ratio by oligomycin or antimycin A was more pronounced at limiting CO2 than at optimal CO2. The mitochondrial oxidative electron transport, through both cytochrome and alternative pathways, therefore akppears to be more important than oxidative phosphorylation in optimizing photosynthesis, particularly at limiting CO2 (when ATP demand is expected to be low). Our results also confirm that the alternative pathway has a significant role in contributing to the cellular ATP, when the cytochrome pathway is limited.  相似文献   

18.
Influence of growth temperature on the capacity of the mitochondrial alternative pathway of electron transport was investigated using etiolated corn (Zea mays L.) seedlings. These seedlings were grown to comparable size in either a warm (30°C) or a cold (13°C) temperature regime, and then their respiration rates were measured as O2 uptake at 25°C. The capacity of the alternative pathway (KCN-insensitive O2 uptake) was found essentially to double in shoots of cold-grown seedlings. This increased capacity slowly developed over several days growth in the cold, but was lost within 1 day when the seedlings were exposed to a warm regime. When mitochondria were isolated from the shoots of these seedlings, a greater potential for flow through the alternative path was observed in mitochondria from the cold-grown seedlings with all substrates used (an average increase of 84%). Using exogenous NADH as the substrate, the effect of the electrochemical gradient on measurable capacities of the cytochrome and alternative pathways was investigated in mitochondria from both etiolated seedlings and thermogenic spadices. The uncoupler FCCP (p-trifluoromethoxycarbonylcyanide phenylhydrazone) was used to diminish the electrochemical gradient when desired. In corn (Zea mays L.) shoot and mung bean (Vigna radiata L.) hypocotyl mitochondria, which have relatively low capacities of the alternative pathway, increased flow through the cytochrome chain in the absence of the electrochemical gradient was found not to influence the potential for flow through the alternative path. However, in mitochondria from skunk cabbage (Symplocarpus foetidus L.) and voodoo lily (Sauromatum guttatum Schott) spadices, which have high capacities of the alternative pathway, increased flow through the cytochrome chain in the absence of the gradient occurred at the expense of flow through the alternative pathway. These results suggest that in mitochondria of thermogenic spadices, the combined capacities of the cytochrome and alternative paths exceed the capacity of the exogenous NADH dehydrogenase. The effect of assay pH on measurable capacities of the cytochrome and alternative paths was determined over a pH range of 5.6 to 8.8 using exogenous NADH as the mitochondrial substrate. When the electrochemical gradient was present, it limited the electron transport rate and little effect of assay pH was observed. However, when formation of the gradient was prevented through inclusion of FCCP, measurable capacities of the cytochrome and alternative paths were found to be greatly influenced by pH. This experiment also revealed that the potential for respiratory control is largely dependent upon the assay pH.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号