Analysis of the sucrose synthase gene family in tobacco: structure, phylogeny, and expression patterns

Abstract

Main conclusionProvide an evolutionary and an empirical molecular genetic foundation of the Sus gene family in tobacco and will be beneficial for further investigations of Sus gene functionsSucrose synthase (Sus) has been well characterized as the key enzyme participating in sucrose metabolism, and the gene family encoding different Sus isozymes has been cloned and characterized in several plant species. However, scant information about this gene family is available to date in tobacco. Here, we identified 14, 6, and 7 Sus genes in the genomes of Nicotiana tabacum, N.sylvestris and N.tomentosiformis, respectively. These tobacco Sus family members shared high levels of similarity in their nucleotide and amino acid sequences. Phylogenetic analysis revealed distinct evolutionary paths for the tobacco Sus genes. Sus1–4, Sus5, and Sus6–7 originated from three Sus precursors, respectively, which were generated by duplication before the split of monocots and eudicots. There were two additional duplications, before and after the differentiation of the Solanaceae, which separately gave rise to Sus3/4 and Sus1/2. Gene exon/intron structure analysis showed that the tobacco Sus genes contain varying numbers of conserved introns, resulting from intron loss under different selection pressures during the course of evolution. The expression patterns of the NtSus genes differed from each other in various tobacco tissues. Transcripts of Ntab0259170 and Ntab0259180 were detected in leaves at all tested developmental stages, suggesting that these two genes play a predominant role in sucrose metabolism during leaf development. Expression of Ntab0288750 and Ntab0234340 were conspicuously induced by low temperature and virus treatment, indicating that these two isozymes are important in meeting the increased glycolytic demand that occurs during abiotic stress. Our results provide an evolutionary and an empirical molecular genetic foundation of the Sus gene family in tobacco, and will be beneficial for further investigations of Sus gene functions in the processes of tobacco leaf development and tobacco resistance to environmental stresses.Electronic supplementary materialThe online version of this article (doi:10.1007/s00425-015-2297-1) contains supplementary material, which is available to authorized users.

Genome-Wide Analysis of the Sucrose Synthase Gene Family in Grape (Vitis vinifera): Structure, Evolution, and Expression Profiles

“…In general, three pivotal mechanisms contribute to gene family evolution and expansion: exon/intron gain or loss, exonization/pseudo-exonization, and insertion/deletion [17]. For the three groups in Figure 2, according to the phylogenetic relationships of five VvSS genes in the present study (see the contents below) and previous work in other plants [49,50], Group III ( VvSS1/VvSS5 ) was the earliest one that expanded from the evolutionary branch. As a result, VvSS1/VvSS5 has the longest evolutionary history, leading to the complex of intron/exon structure.…”

The involvement of wheat U‐box E3 ubiquitin ligase TaPUB1 in salt stress tolerance

“…The accumulation of compatible solutes could maintain intracellular stability and decrease oxidative damage, but also enhance the tolerance of plants to salt stress (Kishor et al 1995; Ashraf and Foolad, 2007). Soluble sugars contribute to osmotic adjustments and the regulation of ROS signaling, and the synthesis of soluble sugars is a critical process under salt stress (Chen et al 2005; Seki et al 2007; Wang et al 2015c). Proline serves as an osmoprotectant when plants are exposed to salt stress (Bartels and Sunkar 2005; Wang et al 2017).…”

Guard cell‐specific upregulation of sucrose synthase 3 reveals that the role of sucrose in stomatal function is primarily energetic

“…SUS is a key enzyme in sugar metabolism and catalyzes the reversible conversion of sucrose and (A)UDP to fructose and (A)UDP-glucose ( Baroja-Fern andez et al, 2009). Six isoforms (SUS1-6 ) have been documented in the genomes of Arabidopsis, rice and rubber tree (Baud et al, 2004;Hirose et al, 2008;Xiao et al, 2014), whereas seven (SUS1-7 ) are present in cotton (Chen et al, 2012) and tobacco (Wang et al, 2015). Although little information is available concerning SUS3, in Arabidopsis, this isoform is highly expressed in guard cells (Bieniawska et al, 2007) in comparison with whole leaves (Bates et al, 2012), whereas, in potato, SUS3 expression is upregulated in guard cell-enriched epidermal fragments under drought conditions (Kopka et al, 1997).…”