番茄SlFUS3-like转录因子在叶片发育中的功能及作用机理研究

B3 proteins are plant-specific transcription factors, its family members are widely involved in many physiological processes such as plant meristem maintenance, root-irradiation, light signal and hormone signal transduction, stress response, etc. However, the functions of B3 proteins in tomato is rarely reported. In the previous study, we overexpressed and silenced the tomato B3 family SlFUS3-like gene. Overexpression of SlFUS3-like make tomato leaves smaller, smoother surface, lower chlorophyll content and slower plant growth speed; In order to further study the mechanism of SlFUS3-like in tomato, this project will use RNA-seq, qPCR to screen differentially expressed key genes, and clarify the regulation of downstream genes by SlFUS3-like. Yeast two-hybrid and BiFC technology will be used to study the interaction between SlFUS3-like and other factors, which obtains the relationship between SlFUS3-like and upstream regulatory factors. Treatment of transgenic tomato plants with hormones and their inhibitors will be used to reveal the relationship between SlFUS3-like and hormones, examination of endogenous hormonal changes and gene alterations in the synthesis and signaling pathway will be used as well. This topic not only helps to clarify the role and molecular mechanism of SlFUS3-like in tomato, but also provides experimental evidence and theoretical basis for the improvement of traits of Solanaceae crops.

B3蛋白是植物特有的转录因子，其家族成员广泛参与植物分生能力维持、根辐建成、光信号和激素转导、逆境胁迫响应等众多生理过程，然而B3蛋白在番茄中的功能却鲜有报道。本课题通过超表达及沉默番茄B3家族SlFUS3-like基因，发现超表达该基因使番茄叶片变小、表面和边缘更光滑，叶绿素含量降低且植株生长缓慢；为进一步研究SlFUS3-like在番茄中的作用机理，本课题拟利用RNA-seq、qPCR筛选差异表达关键基因，明确SlFUS3-like对下游基因的调控；利用酵母双杂交和BiFC技术研究SlFUS3-like与其他因子间的互作，获得其与上游调控因子间的关系；激素及其抑制剂处理转基因植株，检测内源激素变化和其合成及信号通路基因表达变化，揭示SlFUS3-like与激素间的关系。本课题不仅有助于明确SlFUS3-like在番茄中的功能及分子机理，也将为茄科作物的性状改良提供实验证据与理论依据。

B3蛋白是植物特有的转录因子，其家族成员广泛参与植物分生能力维持、根辐建成、光信号和激素转导、逆境胁迫响应等众多生理过程。然而B3蛋白在番茄中的功能却鲜有报道。本项目通过超表达及沉默番茄B3家族SlFUS3-like基因，研究该基因在番茄中的生物学功能及其分子调控机制。表型观察发现，超表达该基因使番茄叶片变小、表面和边缘更光滑，叶绿素含量降低且植株生长缓慢，叶片表面VI型表皮毛增多；叶片中的叶绿体数量减少，叶绿体基粒堆积密度增加。为进一步研究SlFUS3-like在番茄中的作用机理，通过RNA-seq、qPCR、酵母单杂交和GUS报告基因筛选，发现SlFUS3-like转录因子可直接调控SlARF5、SlABI5和SlGH3的转录表达；通过转录组共表达分析、PPI预测、酵母双杂交和BiFC实验发现SlFUS3-like蛋白可与SlWRKY、SlSNF、SlMPK3、SlWRI1和SlABI5相互作用。激素含量检测发现，GA和IAA的含量降低而ABA含量上调，说明SlFUS3-like转录因子蛋白可以与SlWRKY、SlSNF、SlABI5、SlMAPK3和SlWRI1蛋白相互作用，调控SlABI5、SlARF5和SlGH3的转录，进而参与到GA、 ABA和IAA三种激素的调控网络中，最终调控番茄叶片叶绿素合成、叶绿体数量和表皮毛发育，导致叶片表型的变化。本项目的研究成果不仅揭示了SlFUS3-like在番茄中的生物学功能及作用机理，而且为建立番茄叶片发育的调控网络，为茄科作物性状改良提供了重要的实验证据与理论依据。