The molecular and genetic bases of S-RNase-based self-incompatibility
The molecular and genetic bases of S-RNase-based self-incompatibility
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DOI：
10.1105/tpc.016154
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发表时间：
2004-01-01
期刊：
影响因子：
11.6
通讯作者：
Tsukamoto, T
中科院分区：
文献类型：
--
作者：
Kao, TH;Tsukamoto, T
大多数开花植物都会产生完美的花朵，其中雄性和雌性生殖器官都非常接近。因此，如果没有机制阻止它们，它们就会有强烈的自体受精倾向。由于近交会导致后代的适应性下降，因此雌雄同体植物采取了多种繁殖策略，包括自交不亲和（SI），通过这种策略可以防止近交并促进异交。 SI 允许花朵的雌蕊区分遗传相关（自体）和不相关（非自体）花粉。这种自体/非自体识别导致柱头表面自体花粉萌发的抑制或花柱内自体花粉管生长的抑制。因此，SI是一种合子前的生殖屏障，通过它阻止不相容的花粉/花粉管将精子细胞输送到卵巢以实现双受精。根据是否与花多态性相关，SI可以分为同型和异型类型。在表现出同态 SI 的物种中，所有个体都会产生相同类型的花，并且授粉的结果仅取决于雄性和雌性伴侣的遗传特性。相反，表现出异形SI的物种产生两种或三种不同的花形态（例如，具有短花药和长花柱的花或具有长花药和短花柱的花）。为了成功授粉，花粉必须来自于遗传无关的个体，其花药与被授粉的花的花柱高度相同。迄今为止，我们对 SI 分子基础的了解大部分都是从同态 SI 的研究中推导出来的，这将是本次综述的重点。 de Nettancourt (2001) 的专着提供了关于 SI 的全面论述，包括对异态类型的讨论。
The majority of flowering plants produce perfect flowers that contain both the male and female reproductive organs in close proximity; consequently, they would have a strong tendency to self-fertilize if there were no mechanisms to prevent them from doing so. Because inbreeding can result in reduced fitness in the progeny, hermaphroditic plants have adopted a variety of reproductive strategies, including self-incompatibility (SI), by which inbreeding is prevented and outcrosses are promoted. SI allows the pistil of a flower to distinguish between genetically related (self) and unrelated (non-self) pollen. This self/non-self recognition results in the inhibition of germination of self-pollen on the stigmatic surface or the inhibition of growth of self-pollen tubes in the style. Thus, SI is a prezygotic reproductive barrier by which incompatible pollen/pollen tubes are prevented from delivering the sperm cells to the ovary to effect double fertilization.SI can be classified into homomorphic and heteromorphic types based on whether it is associated with floral polymorphism. In species that exhibit homomorphic SI, all individuals produce the same type of flower and the outcome of pollination depends only on the genetic identity of the male and female partners. In contrast, species that exhibit heteromorphic SI produce two or three different flower morphologies (eg, a flower with short anthers and long style or a flower with long anthers and short style). For successful pollination, pollen must come from genetically unrelated individuals whose anthers are of the same height as the style of the flower being pollinated. To date, much of what we know about the molecular basis of SI has been deduced from studies of homomorphic SI, which will be the focus of this review. A monograph by de Nettancourt (2001) provides a comprehensive treatise on SI, including a discussion of the heteromorphic type.