基于微观结构与水孔蛋白基因的枣果采后失水机制研究

Water migration and loss is the main restrictive factor for storage of jujube fruits during postharvest periods, exploring the mechanism of water loss for postharvest jujube fruits and proposing novel strategies for regulating water loss possesses important theoretical and actual significance. The migration and loss of water in jujube is a complicate biochemical process, which is induced by internal and external environmental factors. The microstructure and the aquaporins, a membrance intrinsic protein mediating the transportation of water, are the possible critical factors for regulating the migration and loss of water in jujube fruits. This study will firstly establish the water loss kinetics of postharvest jujube fruits regulated by artificial methods with the low field nuclear magnetic resonance (LF-NMR) imaging technology for screening out the jujube fruits with significantly different water loss rate. To explore the intrinsic relationship between microstructure and water loss of postharvest jujube fruits, the differences of tissue structure, cell apparent morphology, cell ultra-microstructure and compositions among the screened jujube fruits, as well as their dynamic changes during postharvest periods will be characterized with diverse microscopic inspection measures and physiochemical analysis methods. In addition, the aquaporins gene of jujube fruits will be cloned with reverse transiption-PCR and rapid-amplification of cDNA ends (RACE) molecular biology techniques and its characteristics will be analyzed with bioinformatics tools. In the meanwhile, the tissue expression specificities and responses to water stress and aquaporins inhibitors will also be characterized with semiquantitative PCR and real-time PCR methods, for elucidating the mechanism of water loss, facilitating proposing novel strategies for the regulation of water loss.

水分迁移与散失是枣果采后贮运保鲜的主要限制因素，探讨枣果采后失水机制对提出失水调控新策略具有重要的理论和实践意义。采后枣果的水分迁移与散失是由内在和外在因素诱发的复杂生化过程，其中枣果微观结构与介导水分运输的水孔蛋白可能是调控水分迁移和散失的关键内因。本项目采用低场核磁成像技术建立人为调控和自然状态下枣果的采后失水动力学，筛选失水速率显著不同的枣果，利用显微观察技术研究枣果组织结构、细胞表观形态、细胞超微结构及组分的差异，确定影响枣果失水的关键微观结构及其在采后的变化，明晰枣果微观结构与枣果水分迁移散失的内在联系。通过反转录PCR、RACE等技术克隆枣果水孔蛋白基因，采用生物信息学手段研究其特征，利用半定量PCR和实时定量PCR技术研究其组织表达特性及其对水分胁迫与水孔蛋白抑制剂的响应，明晰水孔蛋白基因在调控枣果水分迁移散失的作用，探讨枣果采后失水的可能机制，提出采后枣果失水控制的新策略。

水分迁移与散失是枣果采后贮运保鲜的主要限制因素，探讨枣果采后失水机制对提出失水调控新策略具有重要的理论和实践意义。采后枣果的水分迁移与散失是由内在和外在因素诱发的复杂生化过程，其中枣果微观结构与介导水分运输的水孔蛋白是调控水分迁移和散失的关键内因。本项目采用低场核磁成像技术建立了人为调控和自然状态下枣果的采后失水动力学，筛选失水速率显著不同的枣果冬枣和金丝小枣，利用显微观察技术研究枣果组织结构、细胞表观形态、细胞超微结构及组分的差异，发现枣果角质层蜡质组分、微观结构影响枣果失水速率。通过反转录PCR、RACE等技术克隆枣果水孔蛋白基因和蜡质基因，采用生物信息学手段研究其特征，利用半定量PCR和实时定量PCR技术研究其组织表达特性及其对水分胁迫的响应，明晰水孔蛋白基因和蜡质基因在调控枣果水分迁移散失的作用。