Cellular regulation of pollen compatibility and fertility in the Brassicaceae

十字花科花粉相容性和育性的细胞调节

• 批准号: RGPIN-2018-04348
• 负责人: Goring, Daphne
• 金额: $ 4.74万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=712921
• 关键词: Cellular; regulation; pollen; compatibility; fertility

In the Brassicaceae (mustard family), sexual plant reproduction is initiated when pollen grains (male) are deposited on top of the pistil (female). Compatible pollen grains are recognized by the pistil and provided resources so that the pollen grains can germinate and produce pollen tubes to deliver sperm cells for fertilization. These pollen-pistil interactions are tightly-regulated and critical as fertilization initiates seed production. The Goring research group examines the first stage of these interactions: when the pollen comes in contact with stigmatic papillar cells at the top of pistil. These papillae can differentiate between different pollen to accept, reject or ignore the pollen grains. Compatible pollen is accepted as it is recognized as being closely-related. In contrast, self'-pollen is rejected in many species as this self-recognition system is used to prevent inbreeding (self-incompatibility). Finally, pollen that is ignored is simply too distantly-related to be recognized. Thus, these initial interactions carefully regulate and conserve the sharing of resources from the female pistil to the male pollen for successful fertilization. For this grant proposal, the Goring research group will investigate the cell-cell communication events that regulate the initial pollen-stigmatic papillae interactions and examine how these processes are conserved in different Brassicaceae species. Specifically, three objectives are proposed for this research: (1) Identify and characterize the signaling proteins in the stigmatic papillae (pistil) that are responsible for recognizing and responding to compatible pollen (e.g. receptors). The mechanism by which stigmatic papillae recognize compatible pollen is currently unknown. (2) Investigate the mechanism of regulated secretion in the basal compatible pollen response pathway. This is the cellular system in the stigmatic papillae that is hypothesized to be responsible for allocating resources to the compatible pollen grains. (3) Define the role and mechanism of autophagy in self-incompatible pollen rejection. This is a cellular response in the stigmatic papillae that is hypothesized to play an important role in rejecting self'-pollen to prevent inbreeding. Through these three objectives, the proposed research is expected to lead to significant new discoveries on the mechanisms regulating early post-pollination processes in the Brassicaceae. Ultimately, successful compatible pollen acceptance has a positive impact on fertilization and seed production, and self-incompatible pollen rejection prevents inbreeding to produce healthier offspring. Hence, this research has important implications for developing new strategies to improve seed productivity in Brassicaceae oilseed crops such as canola.

在十字花科(芥菜科)中，当花粉粒(雄性)沉积在雌蕊顶部(雌性)时，植物开始有性繁殖。相容的花粉粒被雌蕊识别并提供资源，以便花粉粒能够萌发并产生花粉管，以输送精子进行受精。这些花粉-雌蕊的相互作用受到严格的调控，在受精开始种子生产时是至关重要的。戈林研究小组研究了这些相互作用的第一阶段：当花粉与雌蕊顶部的柱头乳头细胞接触时。这些乳突可以区分不同的花粉，以接受、拒绝或忽略花粉粒。亲和的花粉被接受，因为它被认为是密切相关的。相反，自体花粉在许多物种中被排斥，因为这种自我识别系统被用来防止近亲交配(自交不亲和)。最后，被忽视的花粉只是亲缘关系太远而无法辨认。因此，这些最初的相互作用仔细地调节和保存了从雌性雌蕊到雄性花粉的资源共享，以实现成功受精。 对于这项拨款提案，戈林研究小组将调查调节初始花粉-柱头乳突相互作用的细胞-细胞通讯事件，并研究这些过程如何在不同的十字花科物种中保存。具体地说，本研究提出了三个目标： (1)鉴定和鉴定柱头乳突(雌蕊)中负责识别和响应亲和花粉的信号蛋白(如受体)。柱头乳突识别亲和花粉的机制目前尚不清楚。 (2)探讨基本亲和花粉反应途径的分泌调控机制。这是柱头乳突中的细胞系统，被认为负责将资源分配给相容的花粉粒。 (3)明确自噬在自交不亲和花粉排斥中的作用和机制。这是柱头乳突中的一种细胞反应，被认为在拒绝自体花粉以防止近亲交配方面发挥重要作用。 通过这三个目标，这项拟议的研究有望在调节十字花科植物授粉后早期过程的机制方面取得重大的新发现。最终，成功的亲和花粉接受对受精和种子生产有积极影响，自交不亲和花粉排斥阻止近亲交配产生更健康的后代。因此，本研究对于开发油菜科油菜等油料作物种子生产力的新策略具有重要意义。