Analyses of the sucrose synthase gene family in cotton: structure, phylogeny and expression patterns

Abstract

BackgroundIn plants, sucrose synthase (Sus) is widely considered as a key enzyme involved in sucrose metabolism. Several paralogous genes encoding different isozymes of Sus have been identified and characterized in multiple plant genomes, while limited information of Sus genes is available to date for cotton.ResultsHere, we report the molecular cloning, structural organization, phylogenetic evolution and expression profiles of seven Sus genes (GaSus1 to 7) identified from diploid fiber cotton (Gossypium arboreum). Comparisons between cDNA and genomic sequences revealed that the cotton GaSus genes were interrupted by multiple introns. Comparative screening of introns in homologous genes demonstrated that the number and position of Sus introns are highly conserved among Sus genes in cotton and other more distantly related plant species. Phylogenetic analysis showed that GaSus1, GaSus2, GaSus3, GaSus4 and GaSus5 could be clustered together into a dicot Sus group, while GaSus6 and GaSus7 were separated evenly into other two groups, with members from both dicot and monocot species. Expression profiles analyses of the seven Sus genes indicated that except GaSus2, of which the transcripts was undetectable in all tissues examined, and GaSus7, which was only expressed in stem and petal, the other five paralogues were differentially expressed in a wide ranges of tissues, and showed development-dependent expression profiles in cotton fiber cells.ConclusionsThis is a comprehensive study of the Sus gene family in cotton plant. The results presented in this work provide new insights into the evolutionary conservation and sub-functional divergence of the cotton Sus gene family in response to cotton fiber growth and development.

Genome-Wide Identification and Expression Profile Analysis of Citrus Sucrose Synthase Genes: Investigation of Possible Roles in the Regulation of Sugar Accumulation

“…In the structural evolutionary history of gene families, exon/intron insertion or deletion or both events between the paralogs may be happening to some extent and represent attribution features [28]. In the present study, the number and position of introns of six putative Sus genes were different in size but showed parallel positions and were flanked by GT-AG boundaries, highly consistent with rubber [8], poplar [15] and cotton [13]. In addition, we also found that the six putative CitSus isozymes were evenly distributed into the three plant Sus groups (SusI, SusII and SusIII) (Figure 2), similar with other plant Sus gene distribution [8], [11], [13], [15], [19].…”

“…In the present study, the number and position of introns of six putative Sus genes were different in size but showed parallel positions and were flanked by GT-AG boundaries, highly consistent with rubber [8], poplar [15] and cotton [13]. In addition, we also found that the six putative CitSus isozymes were evenly distributed into the three plant Sus groups (SusI, SusII and SusIII) (Figure 2), similar with other plant Sus gene distribution [8], [11], [13], [15], [19]. Moreover, the three C. unshiu Sus genes identified by Komatsu et al [20] were clustered into two Sus dicot sub-groups in the present study, similar to a previously constructed phylogenetic tree [20].…”

Transcriptome Analysis of Ten-DPA Fiber in an Upland Cotton (<i>Gossypium hirsutum</i>) Line with Improved Fiber Traits from Phytochrome A1 RNAi Plants

“…It was reported that the expression level of Sus 1 was low in 10 DPA fiber [43], which was perfectly consistent with the finding in this study. Although GhSus3 (U73588) has been demonstrated to play an important role in ovule development and fiber cell initiation, the functional characterization of Sus genes however was limited [43]. The development of fiber is a complex process, and there are some overlapping processes among each developmental stage.…”

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

“…This classification was corroborated a number of subsequent studies, and three groups were respectively named as the Class I, Class II, and Class III groups [2,28,56]. Later, the Class I group can be further divided into a monocot subgroup and a eudicot subgroup, as these two subgroups were obviously distinct from each other in phylogenetic trees constructed by dozens of plant SS gene families.…”