Structure and expression profile of the sucrose synthase gene family in the rubber tree: indicative of roles in stress response and sucrose utilization in the laticifers. (26th November 2013)

• Record Type: Journal Article
• Authors: Xiao, Xiaohu; Tang, Chaorong; Fang, Yongjun; Yang, Meng; Zhou, Binhui; Qi, Jiyan; Zhang, Yi
• Is Part Of: FEBS journal. Volume 281:Number 1(2014)
• Page Start: 291
• Page End: 305
• Publication Date: 2013-11-26
• Subjects: Biochemistry -- Periodicals; Molecular biology -- Periodicals; Pathology, Molecular -- Periodicals; 572
• DOI: 10.1111/febs.12595
• Languages: English
• ISSNs: 1742-464X

Abstract

<abstract abstract-type="main" id="febs12595-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Sucrose synthase (Sus, EC 2.4.1.13) is widely recognized as a key enzyme in sucrose metabolism in plants. However, nothing is known about this gene family in <italic>Hevea</italic> <italic>brasiliensis</italic> (para rubber tree). Here, we identified six <italic>Sus</italic> genes in <italic>H. brasiliensis</italic> that comprise the entire Sus family in this species. Analysis of the gene structure and phylogeny of the <italic>Sus</italic> genes demonstrates evolutionary conservation in the Sus families across <italic>Hevea</italic> and other plant species. The expression of <italic>Sus</italic> genes was investigated via Solexa sequencing and quantitative PCR in various tissues, at various phases of leaf development, and under abiotic stresses and ethylene treatment. The <italic>Sus</italic> genes exhibited distinct but partially redundant expression profiles. Each tissue has one abundant <italic>Sus</italic> isoform, with <italic>HbSus3</italic>, <italic> 4</italic> and <italic>5</italic> being the predominant isoforms in latex (cytoplasm of rubber‐producing laticifers), bark and root, respectively. <italic>HbSus1</italic> and <italic>6</italic> were barely expressed in any tissue examined. In mature leaves (source), all <italic>HbSus</italic> genes were expressed at low levels, but <italic>HbSus3</italic> and <italic>4</italic> were abundantly expressed in immature leaves (sink). Low temperature and drought treatments conspicuously induced <italic>HbSus5</italic> expression in root and leaf, suggesting a role in stress responses. <italic>HbSus2</italic> and <italic>3</italic> transcripts were decreased by ethylene treatment, consistent with the reduced sucrose‐synthesizing activity of Sus enzymes in the latex in response to ethylene stimulation. Our results are beneficial to further determination of functions for the <italic>Sus</italic> genes in <italic>Hevea</italic> trees, especially roles in regulating latex regeneration.</p> </abstract>