Interplay among Antioxidant System, Hormone Profile and Carbohydrate Metabolism during Bud Dormancy Breaking in a High-Chill Peach Variety

Abstract

(1) Background: Prunus species have the ability to suspend (induce dormancy) and restart growth, in an intricate process in which environmental and physiological factors interact. (2) Methods: In this work, we studied the evolution of sugars, antioxidant metabolism, and abscisic acid (ABA) and gibberellins (GAs) levels during bud dormancy evolution in a high-chill peach variety, grown for two seasons in two different geographical areas with different annual media temperature, a cold (CA) and a temperate area (TA). (3) Results: In both areas, starch content reached a peak at ecodormancy, and then decreased at dormancy release (DR). Sorbitol and sucrose declined at DR, mainly in the CA. In contrast, glucose and fructose levels progressively rose until DR. A decline in ascorbate peroxidase, dehydroascorbate reductase, superoxide dismutase and catalase activities occurred in both seasons at DR. Moreover, the H2O2-sensitive SOD isoenzymes, Fe-SOD and Cu,Zn-SOD, and two novel peroxidase isoenzymes, were detected. Overall, these results suggest the occurrence of a controlled oxidative stress during DR. GA7 was the major bioactive GA in both areas, the evolution of its levels being different between seasons and areas. In contrast, ABA content decreased during the dormancy period in both areas, resulting in a reduction in the ABA/total GAs ratio, being more evident in the CA. (4) Conclusion: A possible interaction sugars-hormones-ROS could take place in high-chill peach buds, favoring the DR process, suggesting that, in addition to sugar metabolism, redox interactions can govern bud DR, regardless of chilling requirements.

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

“…For instance, in the low-chill peach cultivar “Okinawa,” the glucose level remains unchanged during the endodormancy and increases significantly during the ecodormancy stage ( Hernández et al, 2021b ). In contrast, in a high-chill peach cultivar., “Yumyeong,” glucose level declines throughout the endodormancy and increases in ecodormancy, and similar accumulation pattern was observed in the fructose content ( Hernández et al, 2021a ). It has been also reported that starch accumulates gradually during endodormancy and hydrolyzes into soluble sugars by amylase at dormancy release and bud break ( Gholizadeh et al, 2017 ; Kaufman and Blanke, 2017 ), whereas others show starch degradation throughout the dormancy cycle ( Zhang et al, 2018 ).…”

“…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 ).…”

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

“…However, little is known about the role of NADPH oxidase during dormancy transition in deciduous fruit trees. Both non-enzymatic antioxidants such as glutathione and enzymatic antioxidants such as superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase play crucial roles in maintaining optimum levels of ROS during dormancy [25,[36][37][38][39][40]. Comparisons of several transcriptomic studies showed induction of the same set of genes after exposure to chilling, HC or H 2 O 2 .…”

“…Sugars also provide the carbon skeleton for metabolites necessary for bud differentiation, growth and development. Changes in sugar levels during dormancy and dormancy release have been demonstrated in several woody perennials including apple [21], apricot [22], grape [23], Japanese pear [24], peach [25], and sweet cherry [26].…”

Seed Science Research: Global Trends in Seed Biology and Technology

“…In addition, it has been reported that ROS can stimulate gibberellins (GA) biosynthesis [7,8]. Thus, ROS can favour the decline in the ABA/GAs ratio during seed germination [6,7] in a similar fashion to that reported in the dormancy release in floral buds [9,10].…”