Depth of dormancy in tomato (Lycopersicon esculentum Mill.) seeds is related to the progression of the cell cycle prior to the induction of dormancy

Abstract

Cell cycle activities are initiated following imbibition of non-dormant seeds. However, it is not known whether cell cycle related events other than DNA replication also remain suppressed in imbibed dormant seeds. The objective of this study was to demonstrate that the transitions between the non-dormant and dormant (both primary and secondary) states are reflected in cell cycle events, such as DNA replication and the changing patterns of the microtubular cytoskeleton involved in the processes of growth and development. The present studies were conducted on seeds from tomato (Lycopersicon esculentum cv. Moneymaker) that possessed primary dormancy or were manipulated to attain secondary dormancy. In addition, a non-dormant abscisic acid (ABA)-deficient mutant, sit w , was used. DNA replication, as measured by flow cytometry, and ␤-tubulin accumulation, analysed by immunoblotting, were compared with immunocytological studies of active DNA synthesis and microtubular cytoskeleton formation. It is shown that the depth of dormancy, which distinguishes primary and secondary dormancy, may depend on the progression of the cell cycle prior to the induction of dormancy.

Plant-derived smoke induced activity of amylases, DNA replication and β-tubulin accumulation before radicle protrusion of dormant Avena fatua L. caryopses

“…In dry and dormant A. fatua caryopses imbibed in water at 20°C, 93% of cells in the radicle with coleorhiza (RC) were arrested at the G 1 phase (Table 5; Cembrowska-Lech and Kępczyński 2016). Cells arrested at G 1 were also observed in dry dormant Lycopersicon esculentum seeds (de Castro et al 2001) and in H. vulgare caryopses (Gendreau et al 2012). Analysis of nuclear DNA content during imbibition of dormant caryopses in water may suggest that the dormancy in A. fatua caryopses is associated with inhibition of the cell cycle.…”

“…Thus, it can be concluded that induction of germination of dormant seeds by both SW and KAR 1 involves onset of the cell cycle at phase II, prior to the radicle protrusion. Likewise, dormancy release in seeds of L. esculentum (de Castro et al 2001) was associated with induction of DNA replication before the radicles started protruding through the covering structures. An experiment involving the detection and densitometry analysis indicates that b-tubulin, necessary in the cell cycle, appeared due to SW treatment after 24 h, i.e.…”

“…when the cell cycle was initiated. Earlier studies showed that releasing dormancy in L. esculentum seeds was associated with accumulation of b-tubulin (de Castro et al 2001).…”

The Role of the Cell Cycle Machinery in Resumption of Postembryonic Development

“…Microtubules (MTs) are heterodimeric polymers of a-and b-tubulins in association with other proteins known as MT-associated proteins (MAPs; Lloyd and Hussey, 2001). b-Tubulin accumulation has been extensively studied in relation to seed germination both with immunofluorescence microscopy and western-blot analysis (de Castro et al, 1995(de Castro et al, , 2000(de Castro et al, , 2001Gó rnik et al, 1997;Fujikura et al, 1999;Jing et al, 1999). A correlation between the rate of germination and the rate of b-tubulin accumulation in imbibed tomato (Lycopersicon esculentum) seeds has been demonstrated (de Castro et al, 1995).…”

Nuclear DNA replication and seed quality

“…In imbibed dormant tomato seeds, nuclear DNA replication is blocked (the proportion of the 4C nuclei does not increase above that observed in dry seeds) de Castro et al, 2001). In imbibed dormant tomato seeds, nuclear DNA replication is blocked (the proportion of the 4C nuclei does not increase above that observed in dry seeds) de Castro et al, 2001).…”