茄科酸浆属的一些物种的果实药食同源，其生殖器官（包括花部器官、浆果和种子）的大小协同变化，可分为大、中和小3个组。但这一器官大小自然变异现象的分子遗传调控基础尚不清楚。中科院植物研究所贺超英研究组7月1日在线发表在《自然—通讯》杂志上的研究成果发现了植物果实大小自然变异遗传调控的新机制。

科研人员发现，POS1基因在一种酸浆属植物的生殖器官大小的自然变异中起重要作用。POS1编码一个AP2类的转录因子，它的第一内含子存在一段长度为37bp的调控序列。这一序列拷贝数在大、中、小组中分别为1个、2个和3个串联重复序列。该调控序列拷贝数的变异与POS1基因在生殖器官中的表达量呈显著负相关，而基因的表达量与器官大小呈显著正相关。

研究揭示了由于内含子调控区变异导致调控基因自身表达量改变在器官大小自然变异中的重要作用，发现了一个与番茄大小驯化遗传调控不同的新基因与新机制，对于理解器官形态多样性的进化机制具有重大意义。POS1基因及其调控机制在酸浆属高产新品种培育中具有重要应用前景。（来源：中国科学报 丁佳）

Regulatory change at Physalis Organ Size 1 correlates to natural variation in tomatillo reproductive organ size

Abstract  The genetic basis of size variation in the reproductive organs of tomatillo (Physalis philadelphica) is unknown. Here we report that the expression levels of the gene Physalis Organ Size 1 (POS1) are positively associated with size variation in P. philadelphica reproductive organs such flowers, berries and seeds. POS1 knockdown results in smaller flowers and berries with smaller cells as compared with their wild-type counterparts. Conversely, POS1 overexpression promotes organ size without increasing the cell number. The first introns of the POS1 alleles from the large, intermediate and small tomatillo groups contain one, two and three 37-bp repeats, respectively. Furthermore, our results show that copy variation of repeats in the first intron of POS1 alleles results in differential expression of this gene. Thus, co-variation in tomatillo reproductive organ sizes can be attributed to the novel regulatory variation in POS1.

原文链接： http://www.nature.com/ncomms/2014/140701/ncomms5271/full/ncomms5271.html