Transcriptome and phytohormone changes associated with ethylene-induced onion bulb dormancy

Abstract

Highlights A de novo onion transcriptome was developed to investigate dormancy transition. Continuous ethylene induced a climacteric-like respiration peak in stored onions. Ethylene upregulated ethylene biosynthesis transcripts, ACO1 , in onion baseplates. The ABA biosynthesis gene NCED was upregulated under ethylene supplementation. t ZRP and IPRP are potential markers of onion dormancy status.

New insights into the effects of ethylene on ABA catabolism, sweetening and dormancy in stored potato tubers

“…7 B). Upregulation of ACO gene expression, or ACO enzyme activity, following exogenous ethylene has been described for other storage organs ( Cools et al, 2011 ; Alamar et al, 2020 ), but not for potato tubers. The transcriptomic profiles of ethylene receptors in this work showed that in potato cortex the expression of four receptor genes ( ethylene receptor_a , ethylene receptor_b , ethylene receptor_c and ethylene receptor homolog_b ) was induced by ethylene and inhibited by 1-MCP ( Fig.…”

ABA and Bud Dormancy in Perennials: Current Knowledge and Future Perspective

“…The application of competitive ET antagonist 2,5-Norbornadiene (NBD) leads to premature sprouting in potato tubers [167]. In onion, exogenous ET not only affects the expression of ACO and receptors (EIN4 and EIL3), but also increases the accumulation of ABA by up-regulating the expression of NCED [168]. The etr1-4 mutant in birch had relative low ABA content and fast growth under SD.…”

WRKY Gene Family Drives Dormancy Release in Onion Bulbs

“…At T 3 , ABA levels increased only in infected samples, showing an opposite ABA profiling in the uninfected bulbs. Plant growth hormones seemed to play a crucial role in maintaining bulb dormancy or its breakage, determining sprout elongation [ 5 , 8 , 9 , 10 , 17 ]. In particular, ABA plays a central role in all plants in biological processes related to senescence and dormancy regulation.…”

“…In onion, dormancy occurs between bulb maturity and internal sprouting ( Figure 1 A). Several studies described the role and the crosstalk between different hormones in dormancy release, fructans mobilization, and external sprouting [ 4 , 5 , 6 , 7 , 8 ]. Abscisic acid (ABA), a growth hormone known to be involved in maturation and dormancy, accumulates during bulb growth [ 9 ].…”

“…After harvest, ABA is gradually depleted and reaches the lowest level just before sprout elongation [ 10 ]. By contrast, cytokinin (CK) and gibberellin (GA), correlated to sprout elongation, show opposite behaviors [ 8 , 11 ]. During the shift from dormancy to sprouting, the bulb converts from a sink to a source organ, allowing for cell division in the shoot apical meristem, directly on the basal plate.…”