TY - JOUR

T1 - Early-stage sugar beet taproot development is characterized by three distinct physiological phases

AU - Jammer, Alexandra

AU - Albacete, Alfonso

AU - Schulz, Britta

AU - Koch, Wolfgang

AU - Weltmeier, Fridtjof

AU - van der Graaff, Eric

AU - Pfeifhofer, Hartwig W.

AU - Roitsch, Thomas G.

PY - 2020

Y1 - 2020

N2 - Despite the agronomic importance of sugar beet (Beta vulgarisL.), the early-stage development of its taproot has only been poorly investigated. Thus, the mechanisms that determine growth and sugar accumulation in sugar beet are largely unknown. In the presented study, a physiological characterization of early-stage sugar beet taproot development was conducted. Activities were analyzed for fourteen key enzymes of carbohydrate metabolism in developing taproots over the first 80 days after sowing. In addition, we performed in situ localizations of selected carbohydrate-metabolic enzyme activities, anatomical investigations, and quantifications of soluble carbohydrates, hexose phosphates, and phytohormones. Based on the accumulation dynamics of biomass and sucrose, as well as on anatomical parameters, the early phase of taproot development could be subdivided into three stages-prestorage, transition, secondary growth and sucrose accumulation stage-each of which was characterized by distinct metabolic and phytohormonal signatures. The enzyme activity signatures corresponding to these stages were also shown to be robustly reproducible in experiments conducted in two additional locations. The results from this physiological phenotyping approach contribute to the identification of the key regulators of sugar beet taproot development and open up new perspectives for sugar beet crop improvement concerning both physiological marker-based breeding and biotechnological approaches.

AB - Despite the agronomic importance of sugar beet (Beta vulgarisL.), the early-stage development of its taproot has only been poorly investigated. Thus, the mechanisms that determine growth and sugar accumulation in sugar beet are largely unknown. In the presented study, a physiological characterization of early-stage sugar beet taproot development was conducted. Activities were analyzed for fourteen key enzymes of carbohydrate metabolism in developing taproots over the first 80 days after sowing. In addition, we performed in situ localizations of selected carbohydrate-metabolic enzyme activities, anatomical investigations, and quantifications of soluble carbohydrates, hexose phosphates, and phytohormones. Based on the accumulation dynamics of biomass and sucrose, as well as on anatomical parameters, the early phase of taproot development could be subdivided into three stages-prestorage, transition, secondary growth and sucrose accumulation stage-each of which was characterized by distinct metabolic and phytohormonal signatures. The enzyme activity signatures corresponding to these stages were also shown to be robustly reproducible in experiments conducted in two additional locations. The results from this physiological phenotyping approach contribute to the identification of the key regulators of sugar beet taproot development and open up new perspectives for sugar beet crop improvement concerning both physiological marker-based breeding and biotechnological approaches.

KW - assimilate partitioning

KW - carbohydrate metabolism

KW - developmental regulation

KW - physiological phenotyping

KW - sucrose accumulation

KW - taproot development

KW - SUCROSE-PHOSPHATE SYNTHASE

KW - CELL-WALL INVERTASE

KW - UDP-GLUCOSE PYROPHOSPHORYLASE

KW - COAT-ASSOCIATED INVERTASES

KW - ORGAN-SPECIFIC EXPRESSION

KW - YEAST-DERIVED INVERTASE

KW - EARLY FRUIT-DEVELOPMENT

KW - BETA-VULGARIS L

KW - STORAGE ROOT

KW - CARBOHYDRATE-METABOLISM

U2 - 10.1002/pld3.221

DO - 10.1002/pld3.221

M3 - Journal article

C2 - 32766510

VL - 4

JO - Plant Direct

JF - Plant Direct

SN - 2475-4455

IS - 7

M1 - 00221

ER -