FOR 948: Nitrogen Uptake, Metabolism and Remobilisation in Leaves during Plant Senescence

FOR 948：植物衰老过程中叶片的氮吸收、代谢和再利用

• 批准号: 46691270
• 金额: --
• 依托单位: Abteilung Physiologie und Zellbiologie
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/46691270?language=en
• 关键词: 948; Nitrogen; Uptake; Metabolism; Remobilisation

Establishment of environmentally sound agriculture raises demands for a reduction of nitrogen (N) budget surpluses in crop production through a more efficient use of soil and fertilizer nitrogen. This requires the breeding and cultivation of genotypes with more efficient use of N, allowing a reduction in N supply without yield penalty. N efficiency of crops mainly depends on (1) maintenance of the N uptake capacity in the roots during reproductive growth and (2) efficient retranslocation of N from vegetative to reproductive plants organs during the seed-filling period resulting in leaf senescence. Since leaf senescence leads to decreased allocation of photosynthates to roots (reducing N uptake) and seeds (reducing grain yields) a fine-tuning of leaf senescence regarding the mobilisation of N for reproductive growth and the maintenance of photosynthetic capacity is necessary. The overall hypothesis of the Research Unit is that an in-depth understanding of the physiological and molecular processes controlling leaf senescence in relation to N mobilisation and allocation to reproductive growth will allow developing traits for the breeding of N-efficient crop genotypes. In order to meet this challenge, the Research Unit is composed of plant scientists with agricultural and/or molecular biological background and a seed breeding company integrating studies at the molecular, biochemical, physiological, cytological and whole-plant level. As crops, oilseed rape and barley have been selected. In addition, Arabidopsis will be used for the identification of key genes regulating senescence and for their functional characterisation by reverse genetics. The main objectives of the experimental complementary approaches of the participating research groups are: (1) to characterise and compare the physiological processes and molecular signals governing developmentally regulated senescence versus N deficiency-induced senescence; (2) to determine time-dependent changes of senescence-associated parameters deciphering the potential bottlenecks in N uptake and retranslocation efficiencies; (3) to investigate whether and under which conditions N remobilisation during senescence is sink- or source-limited in relation to N uptake capacities of roots under progressing senescence; (4) to determine the potential for increasing N efficiency in crops by manipulating the expression of genes encoding transcription factors, signalling components, enzymes and transporters.

建立环保农业的建立提出了对通过更有效利用土壤和肥料氮来减少氮（N）预算过剩的需求。这需要更有效地利用N的基因型的繁殖和种植，从而可以减少N供应而不会造成损失。 n农作物的n效率主要取决于（1）在生殖生长过程中维持氮的氮摄取能力，以及（2）在种子填充期间从营养性到生殖植物器官有效地重新分配，导致叶片衰老。由于叶片衰老会导致光合作用分配给根部（减少氮的吸收）和种子（降低谷物产量），因此需要微调叶子衰老，以动员N的生殖生长，并维持光合作用的能力。研究单位的总体假设是，对控制叶片衰老的生理和分子过程的深入了解与N动员和分配以生殖生长有关，将允许发展为N效率的农作物基因型繁殖的特征。为了应对这一挑战，研究部门由具有农业和/或分子生物学背景的植物科学家组成，以及在分子，生化，生理，细胞学，细胞学和全植物水平上整合研究的种子育种公司。作为农作物，已经选择了油料种子强奸和大麦。此外，拟南芥将用于鉴定调节衰老的关键基因及其通过反向遗传学的功能表征。参与研究小组的实验互补方法的主要目标是：（1）表征和比较有关发育范围内衰老的生理过程和分子信号与N缺乏引起的衰老； （2）确定与衰老相关参数的时间依赖性变化，从而解解了N摄取和后平面效率的潜在瓶颈； （3）调查在衰老过程中n固定的条件以及在哪些条件下是否被限制在衰老中的n摄取能力方面的限制或源限制； （4）通过操纵编码转录因子，信号成分，酶和转运蛋白的基因的表达来确定农作物中N效率的潜力。