Determining the Contribution of Tomato Fruit Photosynthesis to Fruit Development and Quality

植物光合作用支持地球上的生命和我们的整个食物链。它通常被认为是发生在叶子中，但我们开始了解到，显着的生产力取决于光合作用在不同的植物器官，需要一个新的理解。最近的综述表明，非叶光合作用可以为生长和发育提供重要的碳源[1]。果实光合作用是特别有趣的，因为许多物种（包括番茄）经历了从绿色光合（或部分光合）代谢到成熟时完全异养代谢的转变。番茄果实中的光合作用功能齐全，占果实总固定碳的10%至20%，并对果实早期发育做出重要贡献[1]。这个及时而令人兴奋的项目将进一步探索这一假设，即在水果叶绿体中设计卡尔文循环可以大大提高产量，水果大小和营养质量。它汇集了NIAB EMR，诺丁汉和埃塞克斯在光合作用和分子生理学方面具有互补专业知识的3个小组，为获得分子和整体植物生理学经验提供了机会。转基因植物产生的果实特异性过表达和下调的基因的卡尔文-本森循环，SBALOTHER和FBPaldolase，将被用来剖析参与果实光合作用在果实发育。水果光合作用的速率和对水果发育过程的影响的量化将使用叶绿素荧光成像在整个水果室和红外气体交换分析[2]在绿色和成熟的水果相对于叶子。将评估短期和长期环境因素对果实生长过程中光合作用速率的影响。将使用尖端显微镜和断层扫描对组织进行探索性结构分析。将测量代谢物、微量营养素、果实品质和色素组成。成功的候选人将在科学团队的友好气氛中工作，并具有帮助同事的精神。你将加入一个由38名博士生组成的团队，在肯特中心的202公顷土地上。

Plant photosynthesis supports life on earth and our entire food chain. It is normally thought of as occurring in leaves but we are beginning to understand that significant productivity depends on photosynthesis in diverse plant organs where a new understanding is needed. A recent review has indicated that non-foliar photosynthesis can provide an important source of carbon for growth and development [1]. Fruit photosynthesis is particularly interesting, as many species (including tomato) undergo a shift from green photosynthetic (or partial photosynthetic) metabolism to fully heterotrophic metabolism on ripening. Photosynthesis in tomato fruit is fully functional, contributes between 10% and 20% of the total fixed carbon of the fruit and makes an important contribution to early fruit development [1]. This timely and exciting project will take this further to explore the hypothesis that engineering the Calvin cycle within fruit chloroplasts can drastically enhance yield, fruit size and nutritional quality. It brings together 3 groups with complementary expertise in photosynthesis and molecular physiology at NIAB EMR, Nottingham and Essex, giving an opportunity to gain experience in molecular and whole plant physiology. Transgenic plants produced with Fruit specific over-expression and down-regulation of genes of the Calvin-Benson cycle, SBPase and FBPaldolase, will be used to dissect the involvement of fruit photosynthesis in fruit development. Quantification of the rates of fruit photosynthesis and the impact on fruit developmental processes will take place using chlorophyll fluorescence imaging in whole fruit chambers and infra-red gas exchange analysis [2] in green and ripening fruits relative to leaves. The effect of short term and long-term environmental factors that regulates photosynthesis rate of fruit during growth will be assessed. Exploratory structural analysis of tissue will take place using cutting edge microscopy and tomography. Metabolites, micronutrients, fruit quality and pigment composition will be measured. The successful candidate will work in a friendly atmosphere within the science teams with a spirit of helping colleagues. You will join a cohort of 38 PhD students on a site with 202 ha in the heart of Kent.