Plant carotenoids are essential for photosynthesis and photoprotection and provide colors in the yellow to red range to non-photosynthetic organs such as petals and ripe fruits. They are also the precursors of biologically active molecules not only in plants (including hormones and retrograde signals) but also in animals (including retinoids such as vitamin A). A carotenoid-rich diet has been associated with improved health and cognitive capacity in humans, whereas the use of carotenoids as natural pigments is widespread in the agrofood and cosmetic industries. The nutritional and economic relevance of carotenoids has spurred a large number of biotechnological strategies to enrich plant tissues with carotenoids. Most of such approaches to alter carotenoid contents in plants have been focused on manipulating their biosynthesis or degradation, whereas improving carotenoid sink capacity in plant tissues has received much less attention. Our knowledge on the molecular mechanisms influencing carotenoid storage in plants has substantially grown in the last years, opening new opportunities for carotenoid biofortification. Here we will review these advances with a particular focus on those creating extra room for carotenoids in plant cells either by promoting the differentiation of carotenoid-sequestering structures within plastids or by transferring carotenoid production to the cytosol.

植物类胡萝卜素对光合作用和光保护至关重要，并为花瓣和成熟果实等非光合作用器官提供黄色至红色范围内的颜色。它们也是生物活性分子的前体，不仅在植物（包括激素和逆行信号）中，而且在动物（包括维甲酸，如维生素 A）中。富含类胡萝卜素的饮食与改善人类健康和认知能力有关，而类胡萝卜素作为天然色素的使用在农业食品和化妆品行业中很普遍。类胡萝卜素的营养和经济相关性激发了大量的生物技术策略来用类胡萝卜素丰富植物组织。大多数改变植物中类胡萝卜素含量的方法都集中在操纵它们的生物合成或降解，而提高植物组织中类胡萝卜素的吸收能力受到的关注却少得多。我们对影响植物类胡萝卜素储存的分子机制的了解在过去几年中大幅增长，为类胡萝卜素生物强化开辟了新的机会。在这里，我们将回顾这些进展，特别关注那些通过促进质体内类胡萝卜素螯合结构的分化或通过将类胡萝卜素的产生转移到细胞质中为植物细胞中的类胡萝卜素创造额外空间的进展。