Carotenoids in plants play several key functions such as acting as light-harvesters, antioxidants (Lado et al., 2016) or being precursors of strigolactones, abscisic acid, volatiles and other signaling compounds (Arbona et al., 2013). Although those functions are well-known in light-exposed tissues, information in belowground organs is limited because of reduced abundance of these pigments. In order to better understand the role of carotenoids in roots, we developed a methodology to increase the abundance of these pigments in underground tissues. We took advantage of the fact that citrus roots exposed to light develop pigmentation in order to increase the carotenoid content. Therefore, here we describe a simple method to increase carotenoids in citrus roots.
Carotenoid abundance in roots is quite limited and, therefore, understanding the role of these compounds becomes difficult. Exposure of roots to light is a simple, fast and useful tool to increase carotenoid levels in these tissues, especially when compared to other genomic approaches such as overexpressing some key genes of the carotenoid biosynthetic pathway (Cao et al., 2015).
Materials and Reagents
Pirex® culture tubes 25 x 150 mm
Disposable syringes (25 ml)
1.5 ml Eppendorf tubes
Citrus seeds (e.g., from a commercial rootstock)
Murashige and Skoog (MS) medium (4,302.09 mg L−1) (Duchefa Biochemie, catalog number: M0221 )
Sucrose (30 g L−1) (any supplier)
Sterile MiliQ-water
Agar (European Bacteriological Agar) (Conda, Pronadisa, catalog number: 1800 )
Manzi, M., Pitarch-Bielsa, M., Arbona, V. and Gómez-Cadenas, A. (2016). Protocol for Increasing Carotenoid Levels in the Roots of Citrus Plants. Bio-protocol 6(24): e2077. DOI: 10.21769/BioProtoc.2077.