Cloning and functional analysis of NADP-ME,a key gene in malic acid metabolism in watermelon
DONG Wei
YANG Congji
XU Shouming
ZHANG Zhou
WU Defeng
LI Junhua
Abstract：Organic acids in watermelon fruits are critical components influencing flavor quality,and elucidating the mo-lecular mechanism of malic acid synthesis and metabolism is of great significance.Through homologous sequence align-ment,two watermelon NADP-malic enzyme genes,designated as ClaNADP-ME3 and ClaNADP-ME4,were cloned.Quantitative real-time PCR(qRT-PCR)and high-performance liquid chromatography(HPLC)analysis revealed that the ex-pression level of ClaNADP-ME4 was negatively correlated the the malic acid content in watermelon.Subcellular localiza-tion analysis using GFP fusion proteins demonstrated that the ClaNADP-ME4 gene was distributed in both the cytoplasm and nucleus.Genetic transformation and overexpression of the ClaNADP-ME4 gene further conformed its function,dem-onstrating that this gene significantly reduced the malic acid content in watermelon fruits.In conclusion,the NADP-ME4 gene plays a role in promoting malic acid metabolism.These findings provide a new target for molecular breeding aimed at improving watermelon quality.
Keywords：WatermelonMalic acidNADP-malic enzymeOverexpression
Publication Date：2025-09-05
Online Publishing Date：2025-09-29(First online date of this platform, not the publication date of the document)
Pages：8( 40-47 )