AUTHOR=Zhang Chunmei , Huang Jian , Li Xingang 

TITLE=Transcriptomic Analysis Reveals the Metabolic Mechanism of L-Ascorbic Acid in Ziziphus jujuba Mill.

JOURNAL=Frontiers in Plant Science

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2016.00122

DOI=10.3389/fpls.2016.00122

ISSN=1664-462X

ABSTRACT=<p>Chinese jujube (<italic>Ziziphus jujuba</italic> Mill.) is the most economically important member of the Rhamnaceae family and contains a high concentration of ascorbic acid (AsA). To explore the metabolic mechanism of AsA accumulation, we investigated the abundance of AsA in the fruit development stages, the leaf and flower of <italic>Z. jujuba</italic> cv Junzao, and the mature fruit of one type of wild jujube (<italic>Z. jujuba</italic> var. <italic>spinosa</italic> Hu, Yanchuan sour jujube). And the expression patterns of genes involved in AsA biosynthesis, degradation, and recycling were analyzed. The result showed that AsA biosynthesis during early fruit development (the enlargement stage) is the main reason for jujube high accumulation. The L-galactose pathway plays a predominant role in the biosynthesis of AsA during jujube fruit development, and the genes <italic>GMP1, GME1, GGP</italic>, and <italic>GaLDH</italic> involved in the determination of AsA concentration during fruit development and in different genotypes; the myo-inositol pathway along with the genes <italic>GME</italic>2 and <italic>GMP</italic>2 in the L-galactose pathway play a compensatory role in maintaining AsA accumulation during the ripening stage. These findings enhance our understanding of the molecular mechanism in regulating AsA accumulation for jujube.</p>