...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of the American Society for Horticultural Science >CO2 assimilation, carbohydrate metabolism, xanthophyll cycle, and the antioxidant system of 'Honeycrisp' apple leaves with zonal chlorosis
【24h】

CO2 assimilation, carbohydrate metabolism, xanthophyll cycle, and the antioxidant system of 'Honeycrisp' apple leaves with zonal chlorosis

机译：CO2同化，碳水化合物代谢，叶黄素循环和“蜂蜜脆”苹果叶片伴有区域性绿化的抗氧化系统

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

To determine the cause of a characteristic zonal chlorosis of 'Honeycrisp' apple (Malus x domestica Borkh.) leaves, we compared CO2 assimilation, carbohydrate metabolism, the xanthophyll cycle and the antioxidant system between chlorotic leaves and normal leaves. Chlorotic leaves accumulated higher levels of nonstructural carbohydrates, particularly starch, sorbitol, sucrose, and fructose at both dusk and predawn, and no difference was found in total nonstructural carbohydrates between predawn and dusk. This indicates that carbon export was inhibited in chlorotic leaves. CO2 assimilation and the key enzymes in the Calvin cycle, ribulose 1,5-bisphosphate carboxylase/oxygenase, NADP-glyceraldehyde-3-phosphate dehydrogenase, phosphoribulokinase, stromal fructose-1,6-bisphosphatase, and the key enzymes in starch and sorbitol synthesis, ADP-glucose pyrophosphorylase, cytosolic fructose-1,6-bisphosphatase, and aldose 6-phosphate reductase were significantly lower in chlorotic leaves than in normal leaves. However, sucrose phosphate synthase activity was higher in chlorotic leaves. In response to a reduced demand for photosynthetic electron transport, thermal dissipation of excitation energy (measured as nonphotochemical quenching of chlorophyll fluorescence) was enhanced in chlorotic leaves under full sun, lowering the efficiency of excitation energy transfer to PSII reaction centers. This was accompanied by a corresponding increase in both xanthophyll cycle pool size (on a chlorophyll basis) and conversion of violaxanthin to antheraxanthin and zeaxanthin. The antioxidant system, including superoxide dismutase and ascorbate peroxidase and the ascorbate pool and glutathione pool, was up-regulated in chlorotic leaves in response to the increased generation of reactive oxygen species via photoreduction of oxygen. These findings support the hypothesis that phloem loading and/or transport is partially or completely blocked in chlorotic leaves, and that excessive accumulation of nonstructural carbohydrates may cause feedback suppression of CO2 assimilation via direct interference with chloroplast function and/or indirect repression of photosynthetic enzymes. [References: 49]
机译：为了确定“蜜糖”苹果（Malus x domestica Borkh。）叶片特征性区域性萎黄的原因，我们比较了褪绿叶和正常叶片之间的CO2同化，碳水化合物代谢，叶黄素循环和抗氧化系统。含绿叶在黄昏和黎明之前积累了较高水平的非结构性碳水化合物，尤其是淀粉，山梨糖醇，蔗糖和果糖，并且在黎明前和黄昏之间未发现总非结构性碳水化合物的差异。这表明绿藻叶片中的碳出口受到抑制。 CO2同化作用和Calvin循环中的关键酶，核糖1,5-双磷酸羧化酶/加氧酶，NADP-甘油醛-3-磷酸脱氢酶，磷酸核糖激酶，间质果糖-1,6-双磷酸酶以及淀粉和山梨醇合成中的关键酶，褪绿叶中的ADP-葡萄糖焦磷酸化酶，胞质果糖-1,6-双磷酸酶和醛糖6-磷酸还原酶显着低于正常叶片。然而，绿藻叶片中的蔗糖磷酸合酶活性较高。为响应对光合作用电子运输需求的减少，在全日照下的褪绿叶中增强了激发能的热耗散（以叶绿素荧光的非光化学猝灭），降低了将激发能转移到PSII反应中心的效率。这伴随着叶黄素循环池大小（以叶绿素为基础）的相应增加，以及紫精质转化为花药黄质和玉米黄质的转变。抗氧化剂系统，包括超氧化物歧化酶和抗坏血酸过氧化物酶以及抗坏血酸库和谷胱甘肽库，在中性绿叶中被上调，以响应通过光还原氧产生的活性氧种类的增加。这些发现支持以下假设：韧皮部叶片的韧皮部加载和/或转运被部分或完全阻断，并且非结构性碳水化合物的过度积累可能通过直接干扰叶绿体功能和/或间接抑制光合酶而导致CO2同化的反馈抑制。 [参考：49]

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号