茄科植物具有重要经济价值，且果实大小变异很大。果实大小的变异是适应性进化或人工选择的结果。阐明果实大小的遗传变异基础是进化发育生物学关注的重要内容。我们在酸浆属中发现的POS1（Physalis Organ Size 1）编码一个含有2个AP2和2个CRF结构域的AP2/ERF类转录因子。该基因第一个内含子中37-bp调控序列拷贝数的变异参与调节POS1的表达量，进而控制细胞大小影响浆果大小。初步研究表明POS1似乎是一个茄科特有的基因，且酸浆属中POS1调控果实大小自然变异的功能很可能代表了一个与番茄大小驯化遗传调控不同的新基因和新机制。因此，POS1类基因的起源及其在茄科中的功能分化机制值得深入研究。本项目拟开展分子进化分析，分子生物学特性分析和相关的功能研究等工作，比较研究贯穿始末，旨在阐明茄科POS1类基因的起源和功能进化等问题，并服务于茄科的遗传改良。

The Solanaceae family has important economic value, and their fruit sizes vary much. The fruit size variation is the result of adaptive evolution or artificial selection. The regulations of genetic variation in fruit size are important contents of evo-devo. The characterized gene POS1 (Physalis Organ Size 1) is an AP2/ERF transcription factor in Physalis, with two AP2 domains and two CRF domains. Copy variation of 37-bp repeats in the first intron of POS1 alleles result in differential expression of this gene, and the POS1 expression levels are positively associated with cell size and berry size. Preliminary study shows that POS1 seems to be a unique gene in Solanaceae. POS1 and its regulation function in physalis fruit size natural variation may represent a new gene and a new mechanism which is different from the genetic regulation of tomato fruit size domestication. Therefore, the origin of POS1 like gene and its functional differentiation mechanism in Solanaceae deserve further study. The project will do molecular evolution analysis, molecular biological characteristics study and functional study. With comparative analysis throughout the whole story, the project will try to elucidate the origin and functional evolution of POS1 like genes in Solanaceae, and help the breeding of Solanaceous crops.