Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Ñuñoa, Santiago 7800003, Chile.
Int J Mol Sci. 2021 Jan 26;22(3):1184. doi: 10.3390/ijms22031184.
Light is an important cue that stimulates both plastid development and biosynthesis of carotenoids in plants. During photomorphogenesis or de-etiolation, photoreceptors are activated and molecular factors for carotenoid and chlorophyll biosynthesis are induced thereof. In fruits, light is absorbed by in the early stages of ripening, which allows a gradual synthesis of carotenoids in the peel and pulp with the onset of chromoplasts' development. In roots, only a fraction of light reaches this tissue, which is not required for carotenoid synthesis, but it is essential for root development. When exposed to light, roots start greening due to chloroplast development. However, the colored taproot of carrot grown underground presents a high carotenoid accumulation together with chromoplast development, similar to citrus fruits during ripening. Interestingly, total carotenoid levels decrease in carrots roots when illuminated and develop chloroplasts, similar to normal roots exposed to light. The recent findings of the effect of light quality upon the induction of molecular factors involved in carotenoid synthesis in leaves, fruit, and roots are discussed, aiming to propose consensus mechanisms in order to contribute to the understanding of carotenoid synthesis regulation by light in plants.
光是一种重要的刺激物，它可以刺激植物的质体发育和类胡萝卜素的生物合成。在光形态建成或去黄化过程中，光受体被激活，从而诱导类胡萝卜素和叶绿素生物合成的分子因子。在果实中，在成熟的早期阶段，类胡萝卜素的合成在果皮和果肉中逐渐进行，伴随着质体的发育。在根中，只有一小部分光到达这个组织，这个组织不需要类胡萝卜素的合成，但对根的发育是必不可少的。当暴露在光下时，由于叶绿体的发育，根开始变绿。然而，在地下生长的胡萝卜的有色主根呈现出与成熟柑橘类水果相似的类胡萝卜素积累和质体发育。有趣的是，当胡萝卜根被光照时，总类胡萝卜素水平下降并发育出叶绿体，类似于暴露在光下的正常根。讨论了光质对叶片、果实和根中参与类胡萝卜素合成的分子因子诱导的影响的最新发现，旨在提出共识机制，以促进对植物中光对类胡萝卜素合成调控的理解。
