@conference{
author = "Ćosić, Tatjana and Anđela, Tomić and Uzelac, Branka and Raspor, Martin and Pokimica, Nina and Devrnja, Nina and Ninković, Slavica",
year = "2023",
abstract = "Deposition of carbohydrates in the lower part of the stem represents a unique feature of kohlrabi (Brassica
oleracea var. gongylodes), a member of Brassicaceae family grown for its high nutritional value. Over the
past decade our team intensely investigated in vitro development and regeneration of this significant crop,
determining, among other specific characteristics, an intricate relation between sucrose, serving as a carbon
source for in vitro growth, and cytokinins (CKs), utilized for the induction of indirect de novo shoot
organogenesis (DNSO). Even though the formation of kohlrabi stem tuber in vitro has not yet been
successfully attained, development of an efficient in vitro system for kohlrabi growth and DNSO opened the
possibility to study sugar metabolism in young kohlrabi plants, including the effects of elevated sucrose
application (6% and 9%) and CKs (trans-zeatin, transZ; thidiazuron, TDZ). Expression analysis of ten
selected genes involved in sugar partitioning in plants, indicated that both sucrose and CKs had similar
influence in the sense of downregulating these genes compared to control grown on plant growth
regulator-free medium with 3% sucrose. TDZ application had the highest effect on relative expression of all
three sucrose synthase genes (SUS1/3/6), particularly in three week-old plantlets (S1), the developmental
stage characterized by callus formation in the CK-treated kohlrabi. This trend was also observed for the
CWINV1, coding for β-fructofuranosidase and UGP1, coding for UTP--glucose-1-phosphate uridylyltransferase
1. On the other hand, high concentration of sucrose induced stronger downregulation of CINV1 (alkaline/
neutral invertase1), HXK1 (hexokinase1), GPI (glucose-6-phosphate isomerase) and SPS1 (sucrose-phosphate
synthase 1). TransZ led to small changes in gene expression, and even led to upregulation of SUS1 and
CINV1. Older plantlets (S2, four week-old, forming de novo shoots on CK treatment) were generally less
affected by applied treatments. In addition, histological sections of treated kohlrabi hypocotyls revealed
distinct changes at morpho-anatomical level. Our results, for the first time, depict effects of sucrose and CK
on activity of soluble sugars-related gene in young kohlrabi, suggesting an altered metabolism and transport
of soluble sugars, providing a starting point to the elucidation of stem tuber development and sugar
partitioning in kohlrabi.",
publisher = "Daejeon: International Association For Plant Biotechnology",
journal = "Proceedings Book: The 15th International Association For Plant Biotechnology Congress: Celebrating 50th Anniversary of the Korean Society for Plant Biotechnology; 2023 Aug 6-11; Daejeon, Korea",
title = "Sucrose and cytokinins alter sugar metabolism in young in vitro grown kohlrabi",
pages = "345-345",
url = "https://hdl.handle.net/21.15107/rcub_ibiss_6111"
}
