Hydrogen Peroxide Increases during Endodormancy and Decreases during Budbreak in Grapevine (Vitis vinifera L.) Buds

Abstract

Changes in the level of hydrogen peroxide (H2O2) is a good indicator to monitor fluctuations in cellular metabolism and in the stress responses. In this study, the changes in H2O2 content during bud endodormancy (ED) and budbreak were analysed in grapevine (Vitis vinifera L.). The results showed a gradual increase in the H2O2 content during the development of bud ED, which was mainly due to an increase in the activity of peroxidases (PODs). The maximum H2O2 content reached in the grapevine buds coincided with the maximum depth of bud ED. In contrast, during budbreak, the H2O2 content decreased. As the plant hormones cytokinin (CK) and auxin play an important role in budbreak and growth resumption in grapevine, the effect of exogenous applications of H2O2 on the expression of genes involved in CK and auxin metabolism was analysed. The results showed that H2O2 represses the expression of the CK biosynthesis genes VvIPT3a and VvLOG1 and induces the expression of the CK-inactivating gene VvCKX3, thus reducing potentially the CK content in the grapevine bud. On the other hand, H2O2 induced the expression of the auxin biosynthesis genes VvAMI1 and VvYUC3 and of the auxin transporter gene VvPIN3, thus increasing potentially the auxin content and auxin transport in grapevine buds. In general, the results suggest that H2O2 in grapevine buds is associated with the depth of ED and negatively regulates its budbreak.

Ethephon-Mediated Bloom Delay in Peach Is Associated With Alterations in Reactive Oxygen Species, Antioxidants, and Carbohydrate Metabolism During Dormancy

“…Treatments with hydrogen cyanamide (HC), a dormancy-breaking agent, were also found to substitute chilling requirements in grapevine and Japanese pear by inducing H 2 O 2 accumulation in the buds ( Kuroda and Sugiura, 2002 ; Liang et al, 2019 ). In both species, the accumulation profile of H 2 O 2 during endodormancy was similar to what we observed in the present study ( Figure 2B ), where H 2 O 2 reaches its peak at endodormancy release and declines during ecodormancy ( Kuroda and Sugiura, 2002 ; Pérez et al, 2021 ). Such pattern was also observed with the ET treatment, except that ET maintained H 2 O 2 at higher levels for an extended period compared to control.…”

“…Maintaining elevated H 2 O 2 levels for a longer time could explain the previously reported ET effects on extending the dormancy period and delaying bloom in peach ( Liu et al, 2021 ). In fact, it was reported that bloom delay in grapevine could be achieved by treating the buds with aminotriazole, an irreversible inhibitor of H 2 O 2 detoxifying enzyme CAT, which consequently sustain a high level of H 2 O 2 for an extended period ( Pérez et al, 2021 ). In addition to H 2 O 2 , rapid accumulation of the O 2 •− was also detected in grapevine buds in response to HC application ( Sudawan et al, 2016 ).…”

“…Bud cells have the capacity to produce and scavenge different forms of ROS at various levels, as a result of a balance between their formation and detoxification, with a tight link to dormancy maintenance and release ( Beauvieux et al, 2018 ; Hernández et al, 2021a ). The ROS generation, including H 2 O 2 , may work as major signaling molecules for the endodormancy release ( Pérez et al, 2021 ). It has also been reported that exogenous H 2 O 2 may substitute for chilling requirements in Japanese pear ( Kuroda et al, 2005 ).…”

Changes in Reactive Oxygen Species, Antioxidants and Carbohydrate Metabolism in Relation to Dormancy Transition and Bud Break in Apple (Malus × domestica Borkh) Cultivars

“…Such divergent H 2 O 2 profile during ecodormancy may, at least partially, explains the differences in bloom dates between the two cultivars. Indeed, in grapevine floral buds, maintaining a high level of H 2 O 2 , by inhibiting H 2 O 2 degradation, leads to delayed budbreak [66]. Together, our data support the hypothesis that removal of H 2 O 2 from the buds through antioxidative mechanisms is required for growth resumption [66].…”

“…Indeed, in grapevine floral buds, maintaining a high level of H 2 O 2 , by inhibiting H 2 O 2 degradation, leads to delayed budbreak [66]. Together, our data support the hypothesis that removal of H 2 O 2 from the buds through antioxidative mechanisms is required for growth resumption [66]. Nevertheless, how H 2 O 2 differentially regulate the release of endodormancy and ecodormancy warrants further investigation.…”