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

植物光合作用支持着地球上的生命和我们整个食物链。它通常被认为发生在叶片中，但我们开始理解，重要的生产力取决于不同植物器官的光合作用，这需要新的理解。最近的一项研究表明，非叶面光合作用可以为植物的生长发育提供重要的碳源。水果的光合作用特别有趣，因为许多物种（包括番茄）在成熟时经历了从绿色光合（或部分光合）代谢到完全异养代谢的转变。番茄果实光合作用功能齐全，贡献了果实总固定碳的10% ~ 20%，对果实早期发育有重要贡献。这个及时而令人兴奋的项目将进一步探索在水果叶绿体内设计卡尔文循环可以大大提高产量，果实大小和营养质量的假设。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，为获得分子和整个植物生理学的经验提供了机会。Calvin-Benson循环基因SBPase和FBPaldolase在果实特异性过表达和下调的转基因植株将被用来解剖果实光合作用在果实发育中的作用。利用全果室的叶绿素荧光成像和相对于叶片的绿色和成熟果实的红外气体交换分析[2]，将对果实光合速率及其对果实发育过程的影响进行量化。评估了影响果实生长过程中光合速率的短期和长期环境因子的影响。组织的探索性结构分析将使用尖端显微镜和断层扫描进行。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氛围中工作，并具有帮助同事的精神。你将加入一个由38名博士生组成的队列，在肯特郡中心一个占地202公顷的地点。

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.