Xenia, the phenomenon in which the pollen genotype directly affects the phenotypic characteristics of maternal tissues (i.e., fruit ripening), has applications in crop production and breeding. However, the underlying molecular mechanism has yet to be elucidated. Here, we investigated whether mobile mRNAs from the pollen affect the ripening and quality-related characteristics of the fruit using cross-pollination between distinct (apple) cultivars. We demonstrated that hundreds of mobile mRNAs originating from the seeds are delivered to the fruit. We found that the movement of one of these mRNAs, (), is coordinated with fruit ripening. Salicylic acid treatment, which can cause plasmodesmal closure, blocks movement, indicating that transcripts may move through the plasmodesmata. To assess the role of mobile transcripts in apple fruit, we created -GFP-expressing apple seeds using GFP-overexpressing pollen for pollination and showed that transcripts in the transgenic seeds move to the flesh, where they promote fruit ripening. Furthermore, we demonstrated that can be transported from the seeds to fruit in the fleshy-fruited species tomato and strawberry. These results underscore the potential of mobile mRNAs from seeds to influence fruit characteristics, providing an explanation for the xenia phenomenon. Notably, our findings highlight the feasibility of leveraging diverse pollen genomic resources, without resorting to genome editing, to improve fruit quality.

中文翻译：

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ACC 氧化酶 3 mRNA 从种子到果肉的移动促进苹果果实成熟


Xenia是花粉基因型直接影响母体组织表型特征（即果实成熟）的现象，在作物生产和育种中具有应用。然而，潜在的分子机制尚未阐明。在这里，我们利用不同（苹果）品种之间的异花授粉，研究了来自花粉的移动 mRNA 是否影响果实的成熟和质量相关特性。我们证明了数百个源自种子的移动 mRNA 被传递到了果实。我们发现这些 mRNA 之一 () 的运动与果实成熟相协调。水杨酸处理可导致胞间连丝闭合，并阻止运动，表明转录本可能穿过胞间连丝移动。为了评估移动转录本在苹果果实中的作用，我们使用 GFP 过表达的花粉创建了表达 GFP 的苹果种子进行授粉，并表明转基因种子中的转录本移动到果肉，促进果实成熟。此外，我们还证明，在肉质水果品种番茄和草莓中，它可以从种子转运到果实。这些结果强调了种子中可移动 mRNA 影响果实特性的潜力，为 xenia 现象提供了解释。值得注意的是，我们的研究结果强调了利用不同花粉基因组资源而不诉诸基因组编辑来提高果实质量的可行性。