Relationship between endodormancy, FLOWERING LOCUS T and cell cycle genes in Vitis vinifera

Abstract

In grapevines, the increased expression of VvFT , genes involved in the photoperiodic control of seasonal growth ( VvAP1, VvAIL2 ) and cell cycle genes ( VvCDKA, VvCDKB2, VvCYCA1, VvCYCB, VvCYCD3.2 ) in the shoot apex relative to the latent bud, suggests a high mitotic activity of the apex which could prevent them to enter into endodormancy. Additionally, the up-regulation of these genes by the dormancy-breaking compound hydrogen cyanamide (H 2 CN 2 ) strongly suggests that VvFT plays a key role in regulating transcriptionally cell cycle genes. At the end of the growing season, short-day (SD) photoperiod induces the transition of latent grapevine buds (Vitis vinifera L) from paradormancy (PD) to endodormancy (ED), which allows them to survive the cold temperatures of winter. Meanwhile, the shoot apex gradually decreases its growth without entering into ED, and as a result of the fall of temperatures at the beginning of autumn, dies. To understand developmental differences and contrasting responses to environmental cues between both organs, the expression of cell cycle genes, and of genes involved in photoperiodic control of seasonal growth in trees, such as FLOWERING LOCUS T (FT), APETALA1 (AP1) and AINTEGUMENTA-like (AIL) was analyzed at the shoot apex and latent buds of vines during the transition from PD to ED. After shift to SD photoperiod, increased expression of cell cycle genes in the shoot apex suggests a high mitotic activity in this organ which could prevent them from entering into ED. Additionally, the increased expression of VvFT, VvAP1and VvAIL2 in the shoot apex, and the up-regulation of VvFT, VvAP1and cell cycle genes VvCDKA, VvCDKB2, VvCYCA.1, by the dormancy-breaking compound hydrogen cyanamide (H2CN2), strongly suggests that VvFT plays a key role in regulating transcriptionally cell cycle genes, giving thus, more support to the model for photoperiodic control of seasonal growth in trees. Furthermore, downregulation of VvFT by the SD photoperiod detected in leaves and buds of grapevines highlights the importance of VvFT in the induction of growth cessation and in ED development, probably by regulating the expression of cell cycle genes.

Abscisic acid catabolism enhances dormancy release of grapevine buds

“…Such regulation of hybrid aspen bud dormancy by ABA signalling was recently confirmed, suggesting a role for ABA in plasmodesmata closure, which prevents growth‐promoting signals such as FT from accessing the meristem (Tylewicz et al, ). In light of (a) the role proposed in the current and former (Zheng et al, ) studies for ABA degradation in grapevine bud dormancy release and (b) the observation of decreased VvFT expression in grapevine buds exposed to SD, and its up‐regulation in response to HC and hypoxia and in parallel with cell cycle activity in active buds (Kühn, Ormeño‐Núñez, Jaque‐Zamora, & Pérez, ; Pérez, Kühn, & Vergara, ; Vergara et al, ; Vergara, Noriega, Parada, Dantas, & Pérez, ), an assumption can be made that the mechanism proposed for poplar may apply to grapevine buds as well.…”

“…In light of (a) the role proposed in the current and former studies for ABA degradation in grapevine bud dormancy release and (b) the observation of decreased VvFT expression in grapevine buds exposed to SD, and its up-regulation in response to HC and hypoxia and in parallel with cell cycle activity in active buds (Kühn, Ormeño-Núñez, Jaque-Zamora, & Pérez, 2009;Pérez, Kühn, & Vergara, 2011;Vergara et al, 2012;Vergara, Noriega, Parada, Dantas, & Pérez, 2016), an assumption can be made that the mechanism proposed for poplar may apply to grapevine buds as well.…”

The Multiple Signals That Control Tuber Formation

“…These include bud dormancy in Vitis vinifera (Vergara et al, 2016), seasonal control of growth in Populus spp. (Böhlenius et al, 2006;Tylewicz et al, 2015), bud dormancy in conifers (Gyllenstrand et al, 2007), meristem growth termination in tomato (Solanum lycopersicum; Shalit et al, 2009), and tuberization in potato (Navarro et al, 2011).…”

Isolation and Gene Expression Analysis of Flowering-related Genes in Lettuce (<i>Lactuca sativa</i> L.)

“…Grafting experiments demonstrated that floral stimuli travel long distances (Notaguchi et al, 2008), and that FT is a main trigger of floral initiation. Reports on FT genes isolated from several plants have shown that they are involved in flowering (Hayama et al, 2007;Lifschitz et al, 2006;Oda et al, 2012;Vergara et al, 2016;Xia et al, 2012). In a previous study, we isolated and characterized the L. sativa FT homolog (LsFT) (Fukuda et al, 2011).…”