Reinvention of hermaphroditism via activation of a RADIALIS-like gene in hexaploid persimmon
Reinvention of hermaphroditism via activation of a RADIALIS-like gene in hexaploid persimmon
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激活类放射状基因在六倍体柿中改造两性生殖
DOI：
10.1038/s41477-022-01107-z
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发表时间：
2022-03-17
期刊：
影响因子：
18
通讯作者：
Akagi, Takashi
中科院分区：
文献类型：
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作者：
Masuda, Kanae;Ikeda, Yoko;Akagi, Takashi
在开花植物中，不同的谱系已经独立地从祖先的雌雄同体状态过渡到各种性系统（1）。多倍体化通常与性系统的这种可塑性有关（2，3）。柿（柿属）通过谱系特异的古倍性化进化出了柿属。最近，六倍体D.柿树已经建立了单性花，并且还表现出响应于自然环境信号（自然雌雄同体，NH）或人工细胞分裂素处理（人工雌雄同体，AH）从雄花到雌雄同体花的回复。我们试图确定这些多倍体特异性回复为两性畸形的分子途径。共表达网络分析确定了特定于NH或AH转换的调控途径。令人惊讶的是，这两种途径似乎是拮抗性的，脱落酸和细胞分裂素信号分别为NH和AH。在导致两性花的两种途径共有的基因中，我们鉴定了一个小Myb RADIALIS样基因，命名为DkRAD，它在六倍体D. kaki。一致的是，DkRAD在两个模式植物中的异位过表达导致雌蕊群的过度生长。这些结果表明，通过多倍体化产生雌雄同体花取决于DkRAD激活，这与现有性别决定途径中的功能丧失无关，而是代表了一条通往（或重塑）雌雄同体的新途径。
In flowering plants, different lineages have independently transitioned from the ancestral hermaphroditic state into and out of various sexual systems(1). Polyploidizations are often associated with this plasticity in sexual systems(2,3). Persimmons (the genus Diospyros) have evolved dioecy via lineage-specific palaeoploidizations. More recently, hexaploid D. kaki has established monoecy and also exhibits reversions from male to hermaphrodite flowers in response to natural environmental signals (natural hermaphroditism, NH), or to artificial cytokinin treatment (artificial hermaphroditism, AH). We sought to identify the molecular pathways underlying these polyploid-specific reversions to hermaphroditism. Co-expression network analyses identified regulatory pathways specific to NH or AH transitions. Surprisingly, the two pathways appeared to be antagonistic, with abscisic acid and cytokinin signalling for NH and AH, respectively. Among the genes common to both pathways leading to hermaphroditic flowers, we identified a small-Myb RADIALIS-like gene, named DkRAD, which is specifically activated in hexaploid D. kaki. Consistently, ectopic overexpression of DkRAD in two model plants resulted in hypergrowth of the gynoecium. These results suggest that production of hermaphrodite flowers via polyploidization depends on DkRAD activation, which is not associated with a loss-of-function within the existing sex determination pathway, but rather represents a new path to (or reinvention of) hermaphroditism.