Carotenoid biosynthesis profiling unveils the variance of flower coloration in Tagetes erecta and enhances fruit pigmentation in tomato
Yaqiong Qiu, Ruipeng Wang, Enqi Zhang, Ya‐Fang Shang, Guodong Feng, Wenjing Wang, Yilong Ma, Wenbo Bai, Wan Zhang, Zhiqiang Xu, Wei Shi, Xiangli Niu
Abstract
Carotenoids play a pivotal role in plant. Tagetes erecta , commonly called marigold, has increasing nutritional and economic value due to its high level of carotenoids in flower. However, the functional genes in the carotenoid biosynthesis of T. erecta have not been studied. In this work, three T. erecta varieties with flowers of yellow, yellow-orange and orange color, respectively, were examined for carotenoids composition and corresponding expression profiling of biosynthetic genes at four developmental stages. The results indicated that the varieties with higher lutein content, orange-flower ‘Juwang’ and yellow-orange ‘Taishan’, exhibited significant upregulation of genes in the upstream biosynthesis pathway, especially PDS ( phytoene desaturase ), PSY ( phytoene synthase ) and ZDS ( zeta-carotene desaturase ), whereas downstream carotenoid cleavage genes CCD ( carotenoid cleavage dioxygenase ) were markedly downregulated throughout flower development in the highest lutein containing variety ‘Juwang’. Furthermore, marigold TePDS , TePSYS3 and TeZDS were isolated and transformed into tomato. Overexpression of TePDS or TeZDS resulted in the promotion of fruit ripening and accumulation of carotenoids in the transgenic lines. On the other hand, marigold TePSYS3 showed multiple effects, not only on fruit carotenogenesis but also on pigmentation patterns in vegetative tissues and plant growth. Taken together, the variations in expression profiles of the biosynthetic genes contribute to dynamic change in carotenoid levels and diversity of flower coloration in T. erecta. These functional genes of T. erecta were verified in tomato and provide targets for genetic improvement of fruit carotenoids accumulation. • Carotenoids composition indicate carotenogenesis variances among different color flowers of T. erecta . • Differentially expressed TePSYs , TePDS TeZDS and TeCCDs contribute to carotenoids accumulation in T. erecta . • TePDS and TeZDS improve fruit ripening and carotenoids accumulation in tomato. • TePSY3 effects pigmentation pattern in fruit and vegetative tissues.