Natural variation in expression of genes associated with carotenoid biosynthesis and accumulation in cassava (Manihot esculenta Crantz) storage root

Abstract

BackgroundCassava (Manihot esculenta Crantz) storage root provides a staple food source for millions of people worldwide. Increasing the carotenoid content in storage root of cassava could provide improved nutritional and health benefits. Because carotenoid accumulation has been associated with storage root color, this study characterized carotenoid profiles, and abundance of key transcripts associated with carotenoid biosynthesis, from 23 landraces of cassava storage root ranging in color from white-to-yellow-to-pink. This study provides important information to plant breeding programs aimed at improving cassava storage root nutritional quality.ResultsAmong the 23 landraces, five carotenoid types were detected in storage root with white color, while carotenoid types ranged from 1 to 21 in storage root with pink and yellow color. The majority of storage root in these landraces ranged in color from pale-to-intense yellow. In this color group, total β-carotene, containing all-E-, 9-Z-, and 13-Z-β-carotene isomers, was the major carotenoid type detected, varying from 26.13 to 76.72 %. Although no α-carotene was observed, variable amounts of a α-ring derived xanthophyll, lutein, was detected; with greater accumulation of α-ring xanthophylls than of β-ring xanthophyll. Lycopene was detected in a landrace (Cas51) with pink color storage root, but it was not detected in storage root with yellow color. Based on microarray and qRT-PCR analyses, abundance of transcripts coding for enzymes involved in carotenoid biosynthesis were consistent with carotenoid composition determined by contrasting HPLC-Diode Array profiles from storage root of landraces IAC12, Cas64, and Cas51. Abundance of transcripts encoding for proteins regulating plastid division were also consistent with the observed differences in total β-carotene accumulation.ConclusionsAmong the 23 cassava landraces with varying storage root color and diverse carotenoid types and profiles, landrace Cas51 (pink color storage root) had low LYCb transcript abundance, whereas landrace Cas64 (intense yellow storage root) had decreased HYb transcript abundance. These results may explain the increased amounts of lycopene and total β-carotene observed in landraces Cas51 and Cas64, respectively. Overall, total carotenoid content in cassava storage root of color class representatives were associated with spatial patterns of secondary growth, color, and abundance of transcripts linked to plastid division. Finally, a partial carotenoid biosynthesis pathway is proposed.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-016-0826-0) contains supplementary material, which is available to authorized users.

Storage Root of Cassava: Morphological Types, Anatomy, Formation, Growth, Development and Harvest Time

“…Tissue cell compositions are as described in Figure 5. The overall chemical composition of CSR has recently been reviewed [1]. The major conclusions indicate that fresh peeled cassava storage roots are rich in carbohydrates (30-35%), low in protein (1-2%), and fat (<1%).…”

“…Diversity in central cylinder of CSR ( Figure 2) for carotenoids ( Figure 2A), and carbohydrate and starch iodine staining pattern ( Figure 2B) indicate a large genetic [1] and are the most popular traits used for genetic breeding proposes [2][3][4].…”

“…carbohydrate (single sugar and starch) content [3], amylose percent variation [4], protein content variation [7], carotenoid content and type variation [1], and gene expression analysis [8][9][10].…”

Determination of Cu, Fe, Mn e Zn Using FAAS in Cassava (Manihot esculenta Crantz) Roots from Eastern Amazon

“…13 Neste contexto, torna-se importante o desenvolvimento de estudos focados na determinação de micronutrientes minerais em raízes de mandioca, cuja literatura ainda é escassa, principalmente envolvendo genótipos da região Amazônica brasileira. Apesar da Organização Mundial de Saúde reiterar a deficiência dos micronutrientes minerais e demais componentes como causa de morte de crianças no mundo, os estudos na literatura tem enfocado a determinação de outros componentes em mandiocas cultivadas em outras regiões do país, como carotenóides [14][15] , macronutrientes minerais 16 e como destaque para as variedades da região amazônica relatam-se estudos moleculares de produção de glicídios. 17 Para a quantificação dos micronutrientes minerais em diversas matrizes alimentares, destaca-se o uso da espectrometria de absorção atômica.…”

Comments on the special issue on tropical crops of FASE

“…The title examples authors listed and the ones added here strengthen the utilization of modern genomics [1,2] , proteomics [3] , new genetic resources [4][5][6] , and biotechnology (Maliwan NACONSIE and Peng ZHANG. Transgenic technologies in cassava for nutritional improvement and viral disease resistance: a key strategy for food security in Africa.…”