Biochemical and molecular mechanisms associated with colour retention in fruit crops

颜色的强度和保留是大多数水果和蔬菜以及一些谷物如玉米粒和最近的“黄金大米”的关键质量性状。在辣椒（辣椒）产品的情况下，如果果实颜色退化或没有达到特定的强度，育种者和初级生产者将无法获得足够的经济回报，作物将变得毫无价值。因此，对于具有稳健的保色表型的种子（杂交种）存在极大的兴趣和商业动机。通过申请人和先正达内部计划之间先前的iCASE资助，申请人已经（i）确定类胡萝卜素是赋予颜色强度的分子，（ii）实施了一种图像分析方法，用于在现场快速确定颜色强度和保留率，（iii）创建了分离颜色保留的发现群体（iv）显示颜色强度和保留是两个独立的性状，以及（v）确定了颜色强度的基因特异性候选物以及负责颜色保持的潜在分子和生物化学成分。后者包括超氧化物歧化酶（SOD）和过氧化氢酶（CAT）的不同水平和同种型丰度，通过对挥发性成分的分析，它们似乎通过脂质过氧化作用引发色素降解。这似乎与木薯块茎中经历的收获后劣化的机制相似（Jia等人，2013年）。植物生理学161，1517），这表明了一般的跨作物的重要性的现象。在本提案中，它打算首先集中在几个加入，显示耐受性和敏感性，颜色保留和使用现代代谢组学和转录组学，以确定过程和候选人参与颜色保留。同时，将进行更集中的生化研究，在这些线的SOD和CAT活性沿着脂质过氧化物种的分析及其与类胡萝卜素的相互作用。随后，将筛选用对照品系和显示保色的基因型制备的固定发现群体的保色性质。在显示差异保色表型的亚群中，将进行代谢组学和转录组学，并阐明保色的分子和生物化学候选物的共定位，以鉴定赋予保色性状的基因组区域。这一活动方案与长期资助的活动以及学术和非学术伙伴的愿望具有协同作用。拟议的实验计划将为学生提供机会，以获得现代“组学”为基础的技术和传统的生物化学研究中的应用/翻译背景下的专业知识。

Colour intensity and retention are key quality traits for most fruits and vegetables as well as some cereals such as maize kernels and more recently "Golden Rice". In the case of hot pepper, (Capsicum), products if fruit colour degrades or does not reach a specified intensity the breeder and primary producer will not obtain adequate financial return and the crop will be rendered worthless. Thus, there is great interest and commercial incentives for seeds (hybrids) having robust colour retaining phenotypes. Through previous iCASE funding between the applicants and the internal Syngenta programme, the applicants have (i) identified carotenoids as the molecules conferring colour intensity, (ii) implemented an image analysis method for the rapid determination of colour intensity and retention in the field, (iii) created a discovery population segregating for colour retention (iv) shown that colour intensity and retention are two separate traits and (v) identified gene specific candidates for colour intensity and potential molecular and biochemical components responsible for colour retention. The latter includes differential levels and isoform abundance of Super Oxide Dismutase (SOD) and Catalase (CAT) enzymes which, through the analysis of volatile components, appear to initiate pigment degradation via lipid peroxidation. This would appear to be a similar mechanism to the post-harvest deterioration experienced in Cassava tuber (Jia, et al. 2013. Plant Physiol. 161, 1517), which demonstrates the generic cross crop importance of the phenomena. In the present proposal it is intended to first focus on several accessions that display tolerance and susceptibility to colour retention and use modern metabolomics and transcriptomics to identify processes and candidates involved in colour retention. Concurrently, more focused biochemical studies will be carried out on SOD and CAT activities in these lines along with the analysis of lipid peroxidation species and their interaction with carotenoids. Subsequently fixed discovery populations prepared with control lines and genotypes displaying colour retention will be screened for colour retention properties. In a sub-population showing differential colour retention phenotypes metabolomics and transcriptomics will be performed and the co-localisation of molecular and biochemical candidates to colour retention elucidated in order to identify genomic regions conferring colour retention traits. This programme of activities is synergistic to the long-term funded activities and aspirations of the academic and non-academic partners. The proposed experimental programme will provide the student with the opportunity to gain expertise in modern "omic" based technologies and traditional biochemical studies in an applied /translational context.