The role of abscisic acid in regulating cucumber fruit development and ripening and its transcriptional regulation

• Published in: Plant physiology and biochemistry Vol. 64; pp. 70 - 79
• Main Authors: Wang, Yanping, Wang, Ya, Ji, Kai, Dai, Shengjie, Hu, Ying, Sun, Liang, Li, Qian, Chen, Pei, Sun, Yufei, Duan, Chaorui, Wu, Yan, Luo, Hao, Zhang, Dian, Guo, Yangdong, Leng, Ping
• Format: Journal Article
• Language: English
• Published: Paris Elsevier Masson SAS 01.03.2013; Elsevier
• Subjects: ABA; ABA metabolism; Abscisic Acid - genetics; Abscisic Acid - metabolism; Abscisic Acid - pharmacology; Amino Acid Sequence; Base Sequence; Biological and medical sciences; Cloning, Molecular; Cucumber; Cucumis - enzymology; Cucumis - genetics; Cucumis - growth & development; Cucumis - metabolism; Dehydration; DNA, Complementary; DNA, Plant; Fruit - enzymology; Fruit - growth & development; Fruit - metabolism; Fruit development and ripening; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Plant; Genes, Plant; Molecular Sequence Data; Plant Growth Regulators - genetics; Plant Growth Regulators - metabolism; Plant Growth Regulators - pharmacology; Plant physiology and development; Plant Proteins - genetics; Plant Proteins - metabolism; Pollination; Sequence Homology; Transcription, Genetic; Transcriptional regulation; ABA; BG; DAF; Transcriptional regulation; Fruit development and ripening; NCED; FW; PA; DPA; ABA metabolism; DAT; CYP; Cucumber; Fruit; Transcription; Cucurbitaceae; Cucumis sativus; Metabolism; Ripening; Vegetable crop; Plant physiology; Dicotyledones; Sesquiterpenes; Angiospermae; Abscisic acid; Plant growth substance; Spermatophyta; Transcription factor; Fructification
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2012.12.015

Cucumber (Cucumis sativus L.), a kind of fruit usually harvested at the immature green stage, belongs to non-climacteric fruit. To investigate the contribution of abscisic acid (ABA) to cucumber fruit development and ripening, variation in ABA level was investigated and a peak in ABA level was found in pulp before fruit get fully ripe. To clarify this point further, exogenous ABA was applied to cucumber fruits at two different development stages. Results showed that ABA application at the turning stage promotes cucumber fruit ripening, while application at the immature green stage had inconspicuous effects. In addition, with the purpose of understanding the transcriptional regulation of ABA, two partial cDNAs of CsNCED1 and CsNCED2 encoding 9-cis-epoxycarotenoid dioxygenase (NCED), a key enzyme in ABA biosynthetic pathway; one partial cDNA of CsCYP707A1 for 8′-hydroxylase, a key enzyme in the oxidative catabolism of ABA and two partial cDNAs of CsBG1 and CsBG2 for β-glucosidase (BG) that hydrolyzes ABA glucose ester (ABA-GE) to release active ABA were cloned from cucumber. The DNA and deduced amino acid sequences of these obtained genes respectively showed high similarities to their homologous genes in other plants. Real-time PCR analysis revealed that ABA content may be regulated by its biosynthesis (CsNCEDs), catabolism (CsCYP707A1) and reactivation genes (CsBGs) at the transcriptional level during cucumber fruit development and ripening, in response to ABA application, dehydration and pollination, among which CsNCED1, CsCYP707A1 and CsBG1 were highly expressed in pulp and may play more important roles in regulating ABA metabolism. ► ABA variation was in accordance with cucumber fruit development and ripening. ► ABA application at the turning stage promotes cucumber fruit ripening. ► ABA application at immature green stage had inconspicuous effects. ► ABA content is under precise transcriptional regulation. ► ABA may play important roles in regulating cucumber fruit ripening.