Integrated Metabolomic and Transcriptomic Analyses Reveals Sugar Transport and Starch Accumulation in Two Specific Germplasms of Manihot esculenta Crantz

Abstract

As a starchy and edible tropical plant, cassava (Manihot esculenta Crantz) has been widely used as an industrial raw material and a dietary source. However, the metabolomic and genetic differences in specific germplasms of cassava storage root were unclear. In this study, two specific germplasms, M. esculenta Crantz cv. sugar cassava GPMS0991L and M. esculenta Crantz cv. pink cassava BRA117315, were used as research materials. Results showed that sugar cassava GPMS0991L was rich in glucose and fructose, whereas pink cassava BRA117315 was rich in starch and sucrose. Metabolomic and transcriptomic analysis indicated that sucrose and starch metabolism had significantly changing metabolites enrichment and the highest degree of differential expression genes, respectively. Sugar transport in storage roots may contribute to the activities of sugar, which will eventually be exported to transporters (SWEETs), such as (MeSWEET1a, MeSWEET2b, MeSWEET4, MeSWEET5, MeSWEET10b, and MeSWEET17c), which transport hexose to plant cells. The expression level of genes involved in starch biosynthesis and metabolism were altered, which may result in starch accumulation. These results provide a theoretical basis for sugar transport and starch accumulation and may be useful in improving the quality of tuberous crops and increasing yield.

Carbon usage in yellow-fleshedManihot esculentastorage roots shifts from starch biosynthesis to cell wall and raffinose biosynthesis via themyo-inositol pathway

“…Several studies examined expression or metabolite patterns in high-starch or highcarotenoid genotypes (Wilson et al (2017), Beyene et al (2018), Ogbonna et al (2021), Xiao et al (2021), Cai et al (2023), Luo et al (2023), Olayide et al (2023)). Beyene et al (2018) for example performed carotenoid enrichment research and successfully increased β-carotene content in cassava roots by coexpression of transgenes for DEOXY-D-XYLULOSE-5-PHOSPHATE SYNTHASE (DXS) and bacterial PHYTOENE SYNTHASE (crtB), both known to play pivotal roles in carotenoid biosynthesis.…”