Physiological and Biochemical Characteristics of Prunus sibirica during Flowering

Prunus sibirica, an ecologically and economically important early-flowering tree species, is susceptible to late frost damage, which can cause yield decline. Recognizing the mechanisms behind physiologic and biochemical processes changes during flowering in P. sibirica is important for regulating its flowering time. In this study, we examined the nutrient levels, reactive oxygen species levels, endogenous hormone levels, and antioxidant enzyme activity during flowering in two P. sibirica clones with different flowering times. We found that high indole-3-acetic acid (IAA) (88.05 μg/L) and low zeatin riboside (ZR) (8.26 μg/L) levels favoured P. sibirica flowering. Low gibberellic acid (GA) (472.17 pg/mL) levels; high abscisic acid (ABA) (325.23 μg/L), jasmonic acid (JA) (1116.62 pmol/L), fructose (11.70 mg/g), and sucrose (8.42 mg/g) levels; and high peroxidase (POD) (197.40 U/g), superoxide dismutase (SOD) (290.29 U/g), and catalase (CAT) (420.37 U/g) activities delayed flowering in P. sibirica. This study revealed the role of nutrients, reactive oxygen species, antioxidant enzymes, and endogenous hormones in P. sibirica flowering.