Articles
The regulatory role of LcGA2oxs in litchi dwarfism
Article number
1447_18
Pages
147 – 154
Language
English
Abstract
Gibberellins (GAs) play a significant role in the growth and development of plants.
A previous study demonstrated a negative correlation between the expression levels of Litchi chinensis GA2-oxidases (LcGA2oxs), which are involved in GA metabolism, and tree vigor of various litchi cultivars.
GA2ox is a crucial enzyme in GA biosynthesis pathway, as it catalyzes the conversion of bioactive GAs into inactive forms.
In order to establish a correlation between GA biosynthesis and litchi growth vigor, the concentrations of various GAs were measured in the apical buds of two cultivars, namely ‘Feizixiao’ (FZX) and ‘Ziniangxi’ (ZNX). The results revealed the presence of 14 GAs in the samples, out of which 9 GAs (GA1, GA3, GA8, GA19, GA20, GA29, GA34, GA51 and GA53) exhibited significantly higher concentrations in FZX than in ZNX. Conversely, only GA4 content was found to be significantly higher in ZNX, while 4 GAs (GA7, GA9, GA12, GA24) showed no discernible difference between FZX and ZNX. Currently, GA1, GA3, GA4, and GA7 are recognized as the bioactive GAs, and three of these were higher in FZX. These findings provide support for the hypothesis that variations in GA levels contribute to the divergent growth vigor observed in FZX and ZNX. In order to examine the regulatory role of LcGA2ox genes in litchi dwarfism, we isolated and characterized three LcGA2oxs (LcGA2ox1, LcGA2ox2, and LcGA2ox3) and assessed their impact on plant growth through ectopic overexpression in Nicotiana tabacum. Overexpression of LcGA2ox1/2/3 genes in transgenic tobacco all resulted in a dominant dwarf phenotype, which indicates that LcGA2oxs indeed negatively regulated plant growth.
This study provides not only the basis for further investigating the function of GAs in litchi growth, but also valuable reference for litchi dwarfing breeding in the future.
A previous study demonstrated a negative correlation between the expression levels of Litchi chinensis GA2-oxidases (LcGA2oxs), which are involved in GA metabolism, and tree vigor of various litchi cultivars.
GA2ox is a crucial enzyme in GA biosynthesis pathway, as it catalyzes the conversion of bioactive GAs into inactive forms.
In order to establish a correlation between GA biosynthesis and litchi growth vigor, the concentrations of various GAs were measured in the apical buds of two cultivars, namely ‘Feizixiao’ (FZX) and ‘Ziniangxi’ (ZNX). The results revealed the presence of 14 GAs in the samples, out of which 9 GAs (GA1, GA3, GA8, GA19, GA20, GA29, GA34, GA51 and GA53) exhibited significantly higher concentrations in FZX than in ZNX. Conversely, only GA4 content was found to be significantly higher in ZNX, while 4 GAs (GA7, GA9, GA12, GA24) showed no discernible difference between FZX and ZNX. Currently, GA1, GA3, GA4, and GA7 are recognized as the bioactive GAs, and three of these were higher in FZX. These findings provide support for the hypothesis that variations in GA levels contribute to the divergent growth vigor observed in FZX and ZNX. In order to examine the regulatory role of LcGA2ox genes in litchi dwarfism, we isolated and characterized three LcGA2oxs (LcGA2ox1, LcGA2ox2, and LcGA2ox3) and assessed their impact on plant growth through ectopic overexpression in Nicotiana tabacum. Overexpression of LcGA2ox1/2/3 genes in transgenic tobacco all resulted in a dominant dwarf phenotype, which indicates that LcGA2oxs indeed negatively regulated plant growth.
This study provides not only the basis for further investigating the function of GAs in litchi growth, but also valuable reference for litchi dwarfing breeding in the future.
Authors
Z. Chen, T.T. Yan, X.H. Wang, F.Z. Wu, Y.S. Dong, W.J. Zhou, F.C. Hu
Keywords
tree vigor, gibberellins, gene expression
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