Dynamics of abscisic acid and indole-3-acetic acid during the early-middle stage of seed development in Rosa hybrida

Abstract

Concentrations of endogenous abscisic acid (ABA) and indole-3-acetic acid (IAA) in Rosa hybrida seed coat and embryos were determined at 28, 35, 42, and 49 days after pollination (DAP), a period encompassing the early-middle stages of seed development. No studies on rose have ever documented simultaneous change in ABA and IAA during these developmental phases in both seed coat and embryo. Plant growth regulators were extracted and then quantified by using high performance liquid chromatography based on solid phase extraction purification. In both the seed coat and embryo, ABA content decreased from 28 DAP (4.39 and 1.36 pmol mg -1 , respectively) and onward. Endogenous IAA in seed coat followed the same trend. In contrast, IAA in embryo began to increase at 28 DAP (2.06 pmol mg -1 ), peaked at 42 DAP (5.06 pmol mg -1 ), and then declined dramatically at 49 DAP (1.17 pmol mg -1 ). In embryo, the IAA/ABA ratio was always [1.0 and showed a tendency to increase from 28 DAP to the maximum significant rate at 42 DAP (9.20).The ABA decrease associated with increased IAA levels in embryo could be a result of crosstalk between these two phytohormones. Such a change in the IAA/ABA ratio may signal the end of endodormancy caused by ABA at the precotyledonary stage and the start of increased embryo cell division during the cotyledonary stage, which also results in increased hip weight.

Abscisic Acid Inhibits Asymbiotic Germination of Immature Seeds of Paphiopedilum armeniacum

“…Our results revealed that the ABA content increased as the seed approach maturation, peaking at 14.6 ng/g. The dynamic change of ABA content in P. armeniacum seed was similar to that of Rosa hybrida , Pinus taeda , and other species [ 33 , 34 ]. There is the possibility that the high level of ABA in the early stage can inhibit the premature germination of seeds [ 35 ].…”

Effects of Cultivar and Ethanol Disinfection on Aseptic Germination of Loquat (Eriobotrya japonica) Seeds

“…2, the ABA content in loquat seeds on the day of harvest ranged greatly between cultivars from 42.76 ng • g -1 FW ('Ninghaibai') to 81.61 ng • g -1 FW ('Oobusa'). The content is lower than those reported for some other Rosaceae plant seeds, e.g., 0.55 pmol • mg -1 (equals to 145.20 ng • g -1 FW) for rose (Rosa hybrida) (Bosco et al, 2015) and 354.65 ng • g -1 FW for 'Cuiguan' sand pear (Pyrus pyrifolia) (Wang et al, 2013). The relatively low content of ABA in loquat seeds might be related to the lack of obvious dormancy in contrast to the obvious seed dormancy in rose and sand pear (Pipino et al, 2013;Wang et al, 2013).…”

In vitro culture to improve breeding activities inRosa hybrida

“…Seeds are mainly used for propagation of rose species, for the production of rootstocks, and in plant breeding to obtain new cultivars (Horn 1992, Pipino et al 2011, Pipino et al 2013, Bosco et al 2015. Ornamental roses are usually propagated by budding or bench-grafting onto rootstocks (Short and Roberts 1991).…”