Comparative transcriptome analysis during tuberous stem formation in Kohlrabi (B. oleracea var. gongylodes) at early growth periods (seedling stages)

Abstract

Tuberous stem of kohlrabi is an important agronomic trait, however, the molecular basis of tuberization is poorly understood. To elucidate the tuberization mechanism, we conducted a comparative transcriptomic analysis between kohlrabi and broccoli at 10 and 20 days after germination (DAG) as tuberous stem initiated between these time points. A total of 5580 and 2866 differentially expressed transcripts (DETs) were identified between genotypes (kohlrabi vs. broccoli) and growth stages (10 DAG vs. 20 DAG), respectively, and most of the DETs were down-regulated in kohlrabi. Gene ontology (GO) and KEGG pathway enrichment analyses showed that the DETs between genotypes are involved in cell wall loosening and expansion, cell cycle and division, carbohydrate metabolism, hormone transport, hormone signal transduction and in several transcription factors. The DETs identified in those categories may directly/indirectly relate to the initiation and development of tuberous stem in kohlrabi. In addition, the expression pattern of the hormone synthesis related DETs coincided with the endogenous IAA, IAAsp, GA, ABA, and tZ profiles in kohlrabi and broccoli seedlings, that were revealed in our phytohormone analysis. This is the first report on comparative transcriptome analysis for tuberous stem formation in kohlrabi at early growth periods. The resulting data could provide significant insights into the molecular mechanism underlying tuberous stem development in kohlrabi as well as in other tuberous organ forming crops.

Rhizosphere regulation with cerium oxide nanomaterials promoted carrot taproot thickening

“…Expansin (EXP), xyloglucan endotransglucosylase/ hydrolase (XTH), and cellulose synthase (CESA) gene families influence plant growth and development in various plant species by regulating cell wall plasticity and expansion to increase the cell number and cell size. 83 The expression of EXLA2, EXB15, XTH8, XTH15 and XTH23 was significantly upregulated by CeO 2 NMs. The up-regulation of EXPs and XTHs were reported during the expansion of storage organs in sweet potato, radish and potato.…”

In Vitro Growth and Regeneration of Brassica oleracea var. gongylodes: A Decade of Research

“…Being more favorable in taste than most other brassicas and comprising a large variety of functional compounds, it is not surprising that kohlrabi has been recently receiving more and more attention both as food and feed [3]. In this context, the number of studies on ex vitro grown kohlrabi has increased, including studies on the metabolism of phenolic compounds and glucosinolates [8,12], their antioxidant and antimicrobial potential [13], biosynthesis of anthocyanin [14,15], effects of plant growth regulators and various means of biofortification on growth, yield, and quality traits of kohlrabi [16][17][18], as well as reports on transcriptomic [19,20] and hormonomic [21] analysis of stem tuber formation.…”