Ornithine decarboxylase regulates putrescine-related metabolism and pollen development in Atropa belladonna

• Published in: Plant physiology and biochemistry Vol. 192; pp. 110 - 119
• Main Authors: Zhao, Tengfei, Zeng, Junlan, Yang, Mei, Qiu, Fei, Tang, Yueli, Zeng, Lingjiang, Yang, Chunxian, He, Ping, Lan, Xiaozhong, Chen, Min, Liao, Zhihua, Zhang, Fangyuan
• Format: Journal Article
• Language: English
• Published: Elsevier Masson SAS 01.12.2022
• Subjects: Atropa belladonna; Metabolism; Ornithine decarboxylase; Pollen development; Polyamines; Tropane alkaloids; Pollen development; Ornithine decarboxylase; Metabolism; Polyamines; Atropa belladonna; Tropane alkaloids
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2022.09.030

Polyamines, including putrescine, spermidine, and spermine, play critical roles in cell physiology by different forms. As a rate-limiting enzyme that converts ornithine to putrescine, ornithine decarboxylase (ODC, EC 1.1.1.37) has been studied in detail in animals and microorganisms, but its specific functions are poorly understood in plants. In this study, the metabolic and developmental roles of the ODC gene were studied through RNAi-mediated suppression of the ODC gene (AbODC) in A. belladonna. Suppression of AbODC reduced the production of precursors of medicinal tropane alkaloids, including putrescine and N-methylputrescine, as well as hyoscyamine and scopolamine. In AbODC-RNAi roots, the production of putrescine and spermidine in free form was reduced, but in the AbODC-RNAi leaves, the content of free polyamines was not altered. In the roots/leaves of AbODC-RNAi plants, the production of conjugated and bound polyamines was reduced. In addition, suppression of the ODC gene resulted in reduction of polyamines and pollen sterility in AbODC-RNAi flowers. In floral organs, GUS-staining results indicated that AbODC was domainantly expressed in pollen. In summary, ornithine decarboxylase not only plays a key role in regulating the biosynthesis of diverse forms of polyamines and medicinal tropane alkaloids, but also participates in pollen development. [Display omitted] •Suppression of AbODC reduced the yield of tropane alkaloids and its precursors.•Inhibition of AbODC expression suppressed the biosynthesis of various polyamines.•In flower, AbODC was dominantly expressed in pollen.•Suppression of the ODC gene resulted in pollen sterility in AbODC-RNAi plants.