Articles
Carbohydrate and hormone levels and related gene expression during flower bud dormancy in an evergreen Rhododendron
Article number
1467_21
Pages
179 – 190
Language
English
Abstract
Global climate change has reduced winter chilling accumulation, leading to insufficient chilling requirements (CR) for dormancy release in plants, particularly for perennial woody species in tropical and subtropical regions.
This disruption severely impairs natural flowering processes.
In the developmental process of bud dormancy, it is often accompanied by adversities such as decreasing temperatures.
Consequently, plants typically respond to changes in the external environment by altering the levels of substances like carbon sources and endogenous hormones.
In this study, to reveal the mechanisms of the flower bud dormancy process, five physiological indicators including soluble sugars, starch, soluble proteins, proline, and the free water to bound water ratio (F/B) were investigated in flower buds of the evergreen Rhododendron ‘KSCH’ at ten sampling dates with three biological replicates throughout the whole dormancy process Principal component analysis (PCA) identified soluble sugars and starch as the most critical regulatory factors during dormancy.
Path analysis further elucidated the regulatory relationships between carbohydrates and other variables (hormones, proline, and F/B) throughout dormancy.
Transcriptome analysis of flower buds at different dormancy stages revealed that the expression patterns of carbohydrate- and hormone-related genes were correlated with their dynamic physiological changes, and 20 functional genes were predicted to be involved in the dormancy induction, maintenance, and release.
This study provides significant insights into the physiological mechanisms underlying bud dormancy in perennial plants, establishing a crucial theoretical foundation for molecular breeding of flowering time regulation and practical cultivation of evergreen Rhododendron in the context of global climate change.
This disruption severely impairs natural flowering processes.
In the developmental process of bud dormancy, it is often accompanied by adversities such as decreasing temperatures.
Consequently, plants typically respond to changes in the external environment by altering the levels of substances like carbon sources and endogenous hormones.
In this study, to reveal the mechanisms of the flower bud dormancy process, five physiological indicators including soluble sugars, starch, soluble proteins, proline, and the free water to bound water ratio (F/B) were investigated in flower buds of the evergreen Rhododendron ‘KSCH’ at ten sampling dates with three biological replicates throughout the whole dormancy process Principal component analysis (PCA) identified soluble sugars and starch as the most critical regulatory factors during dormancy.
Path analysis further elucidated the regulatory relationships between carbohydrates and other variables (hormones, proline, and F/B) throughout dormancy.
Transcriptome analysis of flower buds at different dormancy stages revealed that the expression patterns of carbohydrate- and hormone-related genes were correlated with their dynamic physiological changes, and 20 functional genes were predicted to be involved in the dormancy induction, maintenance, and release.
This study provides significant insights into the physiological mechanisms underlying bud dormancy in perennial plants, establishing a crucial theoretical foundation for molecular breeding of flowering time regulation and practical cultivation of evergreen Rhododendron in the context of global climate change.
Authors
P.P. Zhang, J. Song, L.C. Peng, W.J. Xie, S.F. Li, J.H. Wang, G.H. Du, L. Zhang
Keywords
evergreen Rhododendron, bud dormancy, carbohydrate, endogenous hormones, transcriptional expression
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