Changes in the activities of catalase, peroxidase, and polyphenol oxidase in apple buds during bud break induced by thidiazuron

Abstract

Abstract. The breaking of dormancy in apple buds (Malus domestica Borkh cv. York Imperial) by thidiazuron (N-phenyl-N'-1,2,3,-thidiazol-5-ylurea) was investigated in relation to catalase, peroxidase, and polyphenol oxidase activities and their isoenzyme patterns. The activity and number of isoenzymic components of catalase increased progressively during bud break, then decreased after buds started to grow. Peroxidase activity was highest during dormancy and declined during bud swell, increased at bud break, and decreased after bud expansion. Several isoperoxidases were observed in gel electrophoresis. Similar patterns were found at different growth stages of apple buds except for one peroxidase isoenzyme, P3, which disappeared 12 days after thidiazuron treatment. There was an inverse relationship between the activities of polyphenol oxidase and peroxidase during the development of apple buds. Apple buds have a very similar polyphenol oxidase isoenzyme pattern throughout bud development. However, the appearance and disappearance of minor isoenzymes were also observed. Phloridzin, rutin, p-coumaric, epicatechin, naringin, chlorogenic acid, and catechol were found in apple buds. Among them, phloridzin, rutin, and p-coumaric were the dominant phenolic compounds. Dormant buds contained a high amount of phenolic substances which decreased after bud break (4 days after thidiazuron treatment) then increased until the start of bud expansion. Phenolic compounds are found to be potent modifiers of catalase, peroxidase, and polyphenol oxidase activity, as both inhibitors and stimulators in apple buds.

Study on the expression of dehydrin genes and activities of antioxidativeenzymes in floral buds of two sand pear (Pyrus pyrifolia Nakai) cultivarsrequiring different chilling hours for bud break

“…After cold temperatures and the bud break stage, reactive O 2 -is overproduced; therefore, SOD and POD activities increase to protect the cells from damage. Our results confirm the findings of Wang et al (1991b) and Shao and Ma (2004); they stated that SOD and POD activities rise during the breaking of dormancy. The increasing activities of SOD and POD at the bud break stage (Figures 4A and 4B) confirm Wang et al 's (1991a) suggestion that the SOD and POD enzymes are involved in breaking bud dormancy by detoxifying the tissue of free radicals.…”

Atividade da peroxidase durante o período hibernal de plantas de pessegueiro (Prunus persica (L.) Batsch.) cv. jubileu com e sem sintomas da morte precoce

“…De acordo com Boller et al (1979), o aumento na atividade desta enzima em ramos de pessegueiro estaria relacionado ao processo de conversão do ácido 1-aminociclopropano-1-carboxílico (ACC) em etileno, por meio de reações oxidativas que consomem H 2 O 2 . Wang et al (1991) sugeriram que o H 2 O 2 presente em gemas de macieira seria proveniente de reações catalisadas pelas peroxidases, cujas atividades seriam induzidas pelo frio e/ou pela aplicação de indutores de brotação. A baixa atividade da catalase durante a dormência também contribuiria para o aumento da concentração de H 2 O 2 nestes tecidos.…”

Characteristics of Growth and Physiological Changes during Cold Treatment in Dormant Hanabusaya asiatica

“…It has been proposed that the physiological responses to low temperature during dormancy is detectable by the decrease in abscisic acid (ABA) levels (Xu et al, 2006), and changes in the carbohydrate content (Cappiello and Kling, 1994) and the activities of related enzymes (Wang et al 1991). The Activity in dormancy breaking was accompanied by noticeable changes in the activities of antioxidant enzymes, e.g., peroxidase (Szecsko et al, 2002), catalase (Nir et al, 1993;Scalabrelli et al, 1991) and polyphenoleoxidase (PPO) (Wang et al, …”