State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
PLoS Genet. 2010 Jan 22;6(1):e1000818. doi: 10.1371/journal.pgen.1000818.
Sexual reproduction is essential for the life cycle of most angiosperms. However, pseudovivipary is an important reproductive strategy in some grasses. In this mode of reproduction, asexual propagules are produced in place of sexual reproductive structures. However, the molecular mechanism of pseudovivipary still remains a mystery. In this work, we found three naturally occurring mutants in rice, namely, phoenix (pho), degenerative palea (dep), and abnormal floral organs (afo). Genetic analysis of them indicated that the stable pseudovivipary mutant pho was a double mutant containing both a Mendelian mutation in DEP and a non-Mendelian mutation in AFO. Further map-based cloning and microarray analysis revealed that dep mutant was caused by a genetic alteration in OsMADS15 while afo was caused by an epigenetic mutation in OsMADS1. Thus, OsMADS1 and OsMADS15 are both required to ensure sexual reproduction in rice and mutations of them lead to the switch of reproductive habit from sexual to asexual in rice. For the first time, our results reveal two regulators for sexual and asexual reproduction modes in flowering plants. In addition, our findings also make it possible to manipulate the reproductive strategy of plants, at least in rice.
有性生殖对于大多数被子植物的生命周期至关重要。然而,假胎生是某些禾本科植物的一种重要生殖策略。在这种生殖方式中,无性繁殖体代替有性生殖结构产生。然而,假胎生的分子机制仍然是个谜。在这项工作中,我们在水稻中发现了三个自然发生的突变体,即凤凰(pho)、退化内稃(dep)和异常花器官(afo)。它们的遗传分析表明,稳定的假胎生突变体 pho 是一个双突变体,既包含 DEP 的孟德尔突变,又包含 AFO 的非孟德尔突变。进一步的基于图谱的克隆和微阵列分析表明,dep 突变是由 OsMADS15 中的遗传改变引起的,而 afo 是由 OsMADS1 中的表观遗传突变引起的。因此,OsMADS1 和 OsMADS15 都需要确保水稻的有性生殖,它们的突变导致水稻生殖习性从有性到无性的转变。这是首次揭示开花植物有性和无性生殖模式的两个调控因子。此外,我们的发现还使得操纵植物的生殖策略成为可能,至少在水稻中是这样。