Oilseed‐based metabolic engineering of astaxanthin and related ketocarotenoids using a plant‐derived pathway: Lab‐to‐field‐to‐application

作者：Hyojin Kim, Lingyi Liu, Lihua Han, Kiyoul Park, Hae Jin Kim, Tam Nguyen, Tara J. Nazarenus, Rebecca E. Cahoon, Richard P. Haslam, Ozan N. Ciftci, Johnathan A. Napier, Edgar B. Cahoon · 发表于：Plant Biotechnology Journal · 年份：2025 · DOI：10.1111/pbi.70148 · 被引用次数：9 · 研究领域：Photosynthetic Processes and Mechanisms、Antioxidant Activity and Oxidative Stress、Algal biology and biofuel production

Ketocarotenoids, including astaxanthin, are red lipophilic pigments derived from the oxygenation of β-carotene ionone rings. These carotenoids have exceptional antioxidant capacity and high commercial value as natural pigments, especially for aquaculture feedstocks to confer red flesh colour to salmon and shrimp. Ketocarotenoid biosynthetic pathways occur only in selected bacterial, algal, fungal and plant species, which provide genetic resources for biotechnological ketocarotenoid production. Toward pathway optimization, we developed a transient platform for ketocarotenoid production using Agrobacterium infiltration of Nicotiana benthamiana leaves with plant (Adonis aestivalis) genes, carotenoid β-ring 4-dehydrogenase 2 (CBFD2) and carotenoid 4-hydroxy-β-ring 4-dehydrogenase (HBFD1), or bacterial (Brevundimonas) genes, β-carotene ketolase (crtW) and β-carotene hydroxylase (crtZ). In this test system, heterologous expression of the plant-derived astaxanthin pathway conferred higher astaxanthin production with fewer ketocarotenoid intermediates than the bacterial pathway. We evaluated the plant-derived pathway for ketocarotenoid production using the oilseed camelina (Camelina sativa) as a production platform. Genes for CBFD2 and HBFD1 and maize phytoene synthase were introduced under the control of seed-specific promoters. In contrast to prior research with bacterial pathways, our strategy resulted in nearly complete conversion of β-carotene to ketocarotenoids, including prima...