Integrative transcriptomics reveals genotypic impact on sugar beet storability

Abstract

Key message An integrative comparative transcriptomic approach on six sugar beet varieties showing different amount of sucrose loss during storage revealed genotype-specific main driver genes and pathways characterizing storability. Abstract Sugar beet is next to sugar cane one of the most important sugar crops accounting for about 15% of the sucrose produced worldwide. Since its processing is increasingly centralized, storage of beet roots over an extended time has become necessary. Sucrose loss during storage is a major concern for the sugar industry because the accumulation of invert sugar and byproducts severely affect sucrose manufacturing. This loss is mainly due to ongoing respiration, but changes in cell wall composition and pathogen infestation also contribute. While some varieties can cope better during storage, the underlying molecular mechanisms are currently undiscovered. We applied integrative transcriptomics on six varieties exhibiting different levels of sucrose loss during storage. Already prior to storage, well storable varieties were characterized by a higher number of parenchyma cells, a smaller cell area, and a thinner periderm. Supporting these findings, transcriptomics identified changes in genes involved in cell wall modifications. After 13 weeks of storage, over 900 differentially expressed genes were detected between well and badly storable varieties, mainly in the category of defense response but also in carbohydrate metabolism and the phenylpropanoid pathway. These findings were confirmed by gene co-expression network analysis where hub genes were identified as main drivers of invert sugar accumulation and sucrose loss. Our data provide insight into transcriptional changes in sugar beet roots during storage resulting in the characterization of key pathways and hub genes that might be further used as markers to improve pathogen resistance and storage properties.

Workflow for Phenotyping Sugar Beet Roots by Automated Evaluation of Cell Characteristics and Tissue Arrangement Using Digital Image Processing

“…For vascular cells, there is no size reference yet. The cell sizes measured in the storage parenchyma were on the lower end of the range reported in other studies [9,26,27]. This was mainly in uenced by the fact that in the presented work ow, only the rst 6 mm from the periphery to the center were considered.…”

“…So far, the underlying shape and the real cell size distribution is unknown for sugar beet roots. We have refrained from correcting the measured cell size, as in other published studies of sugar beet roots, no adjustment was made either for real cell size [5,9,10,12,26,27]. But as the possible error is the same for all genotypes (or other treatments) a comparison of those will always be correct…”

Holomics - a user-friendly R shiny application for multi-omics data integration and analysis

“…Therefore, deciphering key factors associated with good storability is crucial because these factors can be used as biomarkers, e.g., to screen available varieties or to optimize breeding programs by including marker-assisted selection (MAS) targeting prolonged storability. Several single-omics studies have already been performed to address the above described problems [ 51 – 53 ]. However, a multi-omics analysis targeting this research question has not yet been performed.…”

Effect of size, storage, age at harvest, and juice season on physicochemical and technological characteristics of sugar beetroot

“…Although changes in the composition of the cell wall and pathogen invasion also contribute to this loss, respiration is the predominant cause. Numerous studies have been conducted to look into how delivery delays affect the characteristics of sugar beets (Tsialtas & Maslaris, 2013;Al-Jbawi et al, 2015;El-Syiad, 2016, Hoffmann & Schnepel, 2016Madritsch et al, 2020). Abd El-Rahman & El-Geddawy, 2019) showed that sugar beet manufacturing at 210 days gives the lowest percentage of nitrogen substance, thus sugar percentage increased in comparison with early periods.This study was carried out to evaluate chemical and quality parameters of different size of sugar beet roots storage at different days and harvest age with different time of working or processing juice season.…”