Newly developed sugarbeet lines with altered postharvest respiration rates differ in transcription factor and glycolytic enzyme expression

Authors: Fugate, Karen; CAMPBELL, LARRY - Former ARS Employee; LAFTA, ABBAS - North Dakota State University; Eide, John; KHAN, MOHAMED - North Dakota State University; Chu, Chenggen; FINGER, FERNANDO - Universidade Federal De Vicosa

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/4/2022
Publication Date: 2/12/2022
Citation: Fugate, K.K., Campbell, L.G., Lafta, A.M., Eide, J.D., Khan, M.F., Chu, C.N., Finger, F.L. 2022. Newly developed sugarbeet lines with altered postharvest respiration rates differ in transcription factor and glycolytic enzyme expression. Crop Science. 62(3):1251-1263. https://doi.org/10.1002/csc2.20729.
DOI: https://doi.org/10.1002/csc2.20729

Interpretive Summary: Respiration is the principal cause for sugar loss in stored sugarbeet roots. Although reducing root respiration rate could mitigate these losses, the development of sugarbeet varieties and storage procedures that reduce respiration are hindered by a lack of knowledge of the internal factors in the sugarbeet root that control storage respiration rate. In this research, we used breeding methods to create two sugarbeet lines that differed in respiration rate and we characterized the genetic differences between these lines. The two new lines will be useful tools for studying root respiration rate during storage and to provide clues to the genetic basis and the internal mechanisms that control storage respiration rate in sugarbeet roots.

Technical Abstract: Respiration is the principal cause for postharvest sucrose loss in sugarbeet (Beta vulgaris L.) roots. Although reductions in respiration rate could mitigate these losses, developing sugarbeet varieties and storage procedures that reduce respiration are hindered by a lack of knowledge of the genetic and metabolic factors that control storage respiration rate. Research was conducted to identify genes and gene products that affect storage respiration rate by creating two sugarbeet lines that differ in respiration rate and characterizing gene expression differences between these lines. Sugarbeet lines F1056 and F1057, that differ by up to 42% in respiration rate, were created by divergent selection of a sugarbeet population using root respiration rate after 30 d in storage as the principal selection criterion. RNA sequencing identified 287 differentially expressed genes (DEGs) between these lines at harvest and after 28 d storage. Of these DEGs, nine encoded transcription factors and five encoded enzymes involved in the respiratory pathway. Other DEGs contributed to a variety of biological and molecular functions based on gene ontology classifications. Of respiratory pathway DEGS, genes for NAD+-dependent and NADP+-dependent forms of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were of note due to their high upregulation in the high respiring line and for their established role in glycolysis, a pathway previously identified as a likely bottleneck in respiratory substrate production. Overall, lines F1056 and F1057 provide new tools for investigating genetic and physiological differences in storage respiration rate and their DEGs identify candidates for genes affecting sugarbeet root respiration rate.