ABA对草莓果实糖代谢相关基因的转录调控及其分子机理

As we know, the plant hormone abscisic acid（ABA）plays an essential role in the regulation of noclimacteric fruits ripening. Previous reports suggested that abscisic acid may be associated with the development and ripening of nonclimacteric fruits via the enzymes related to sugar metabolism, whereas the exact details remains largely unknown. We plan to use metabonomics technology to analyse the expression pattern of components closely related to sugar metabolism in strawberry fruits under exogenous ABA treatment. To investigate the entire changes of the metabolism cascades in strawberry fruits under ABA treatment, we intend to utilize the pattern recognition and multivariate statistical analysis to process the data and build the model of this project. Also, our study will be focus on the differential expression profiling of the genes in strawberry fruits under ABA treatment. Besides, we will screen the functional genes or regulation factors related to sugar metabolism ABA-regulated by intergrating the prolifing patterns of metabonomics and transcriptome. Furthermore, we will confirm the relationship between these functional genes or regulation factors and the components of sugar metabolism in strawberry fruits using realtime PCR. This project is greatly significant in many aspects, including elucidating the sugar metabolism network and its molecular mechanism ABA-regulated, identifying the functional genes related to sugar metabolism in strawberry fruits, and further utilizing these genes to improve the quality of strawberry fruits.

植物激素脱落酸（ABA）对非呼吸跃变型果实成熟具有重要的调控作用；已有研究表明，脱落酸通过糖代谢相关酶调控果实发育与成熟，但确切机理尚不清楚。本项目拟采用代谢组学技术，对外源ABA处理的草莓果实糖代谢密切相关的代谢组分进行代谢谱分析；采用模式识别和多元统计分析进行数据处理和模型建立，从整体上研究ABA处理草莓果实中代谢流的变化。同时，采用转录组学技术，研究ABA处理草莓果实中基因差异表达谱。整合代谢谱和基因表达谱分析结果，筛选与ABA调控相关的糖代谢功能基因或调控因子，并作实时定量PCR分析，以验证其与草莓果实糖代谢相关组分之间的关系。本项目研究对于探讨和阐明ABA调控草莓果实糖代谢相关代谢网络及其分子机理，发掘与草莓果实糖代谢相关功能基因资源并用于果实品质改良，都将具有十分重要的意义。

糖酸代谢是果实发育成熟与品质形成的主要事件。因此，可以将脱落酸调控草莓果实发育成熟过程进一步归结为脱落酸调控果实的糖酸代谢过程。本项目运用代谢组学和转录组学技术分别对这这一过程进行分析，挖掘可能的调控因子和应答基因。项目以红颜草莓为试材，通过对果实激素及其抑制剂处理，发现ABA促进果实成熟，氟啶酮明显抑制果实着色并延缓果实发育，结果表明ABA是果实发育成熟的主要调控激素之一；对ABA合成关键基因NCED的表达分析表明外源ABA对其内源合成油反馈抑制；对独脚金内酯合成关键基因MAX1表达特性分析，明确独脚金内酯是调控草莓果实早期发育激素之一。对代谢组学数据分析，ABA处理后果实中烃、烯、醛、酮、醇等有机物和糖、有机酸、色素类等98种物质变化明显，其中主要糖酸类物质变化显著，结果初步探明了ABA扰动果实糖酸代谢的变化规律。整合代谢组和转录组数据分析，重点分析了在ABA信号转导和初级代谢产物应答两个方面的转录水平分析。初步筛选得到与糖酸代谢的相关的细胞色素代谢关键酶P450家族、糖代谢转运蛋白ABC家族、细胞膜感知激酶RK家族、代谢调节酶E3家族、糖基转移酶UDP家族及转录因子MYB、MYC、WRKY家族；并将这些基因家族在草莓果实发育过程进行了转录水平验证，进一步遴选可能在调控草莓果实发育过程的关键基因，这些结果解析ABA调控草莓果实发育成熟奠定了基础，并为进一步分子育种提供素材。