Changes in melatonin levels in transgenic 'Micro‐Tom' tomato overexpressing ovine AANAT and ovine HIOMT genes. Issue 2 (25th November 2013)

• Record Type: Journal Article
• Authors: Wang, Lin; Zhao, Yu; Reiter, Russel J.; He, Changjiu; Liu, Guoshi; Lei, Qiong; Zuo, Bixiao; Zheng, Xiao Dong; Li, Qingtian; Kong, Jin
• Is Part Of: Journal of pineal research. Volume 56:Issue 2(2014)
• Page Start: 134
• Page End: 142
• Publication Date: 2013-11-25
• Subjects: Pineal gland -- Periodicals; Pineal Gland -- Periodicals; Épiphyse (Glande); Périodique électronique (Descripteur de forme); Ressource Internet (Descripteur de forme); 612.492
• DOI: 10.1111/jpi.12105
• Languages: English
• ISSNs: 0742-3098

Abstract

<abstract abstract-type="main" id="jpi12105-abs-0001"> <title>Abstract</title> <p>In animals, the melatonin biosynthesis pathway has been well defined after the isolation and identification of the four key genes that are involved in the conversion of tryptophan to melatonin. In plants, there are special alternative catalyzing steps, and plant genes share very low homology with the animal genes. It was of interest to examine the phenotype of transgenic Micro‐Tom tomato plants overexpressing the homologous sheep <italic>oAANAT</italic> and <italic>oHIOMT</italic> genes responsible for the last two steps of melatonin synthesis. The <italic>oAANAT</italic> transgenic plants have higher melatonin levels and lower indoleacetic acid (IAA) contents than control due to the competition for tryptophan, the same precursor for both melatonin and IAA. Therefore, the <italic>oAANAT</italic> lines lose the 'apical dominance' inferring that melatonin likely lacks auxin activity. The significantly higher melatonin content in <italic>oHIOMT</italic> lines than <italic>oAANAT</italic> lines provides new proof for the important role of <italic>ASMT</italic> in plant melatonin synthesis. In addition, the enhanced drought tolerance of <italic>oHIOMT</italic> lines will also be an important contribution for plant engineering.</p> </abstract>