Characterization of Squamosa Promoter Binding Protein-LIKE genes in wheat

Abstract

Common wheat (Triticum aestivum) is an allohexaploid (AABBDD), with Triticum urartu (AA) and Aegilops tauschii (DD) as its A and D genome donors. Squamosa Promoter Binding Protein-Like (SPL) genes play important roles in plant development; however, a systematic study of this gene family in wheat is still lacking. Here, we mined the wheat genomes for SPLs and found 19 SPL genes each from the T. urartu and Ae. tauschii genomes. We also identified 58 SPL genes from the hexaploid wheat genome. We then compared the conservation and divergence of SPLs between the two diploid species in gene structures, tissuespecific expression patterns and responses to salt stress, drought and low temperature. For functional studies, two hexaploid wheat SPLs, TaSPL3 (with miR156 site mutated) and TaSPL6, were overexpressed in Arabidopsis and found to be involved in flowering time and biomass accumulation. In addition, a mutant allele (TaSPL6-D R ) with a 47 bp duplication upstream of the SBP domain was found to be associated with maturity date and grain number per spike among landraces from a Chinese wheat mini-core collection. Collectively, our work provides useful knowledge on the sequences and functions of wheat SPL genes that may help future functional studies and molecular breeding.

Identification and positional distribution analysis of transcription factor binding sites for genes from the wheat fl-cDNA sequences

“…46) The SBP domain can combine with the cis-element TNCGTACAA, for which GTAC is the essential core sequence. 47) In wheat, 1365 TFBSs were detected in the non-coding regions of fl-cDNAs (Table 1), and the cis-element containing TNCGTA-CAA was confirmed in wheat (S2 File).…”

Genome-Wide Characterization and Expression Profiling of Squamosa Promoter Binding Protein-Like (SBP) Transcription Factors in Wheat (Triticum aestivum L.)

“…However, even though a little characterization of wheat SBP (TaSBP) family has been done, more is needed [37,38]. In 2015, Wang et al, using common wheat and the genome database of its A and D subgenome donors Triticum urartu L. (AA) and Aegilops tauschii L. (DD), conducted a whole-genome analysis of the wheat SBP family [39]. Compared with the 19 SPL genes present in rice, Wang et al found 13 and 7 complete open reading frames (ORFs) from wheat diploid progenitors Aegilops tauschii L. (DD) and Triticum urartu L. (AA), respectively.…”

Functional Conservation and Divergence among Homoeologs of TaSPL20 and TaSPL21, Two SBP-Box Genes Governing Yield-Related Traits in Hexaploid Wheat

“…In rice, OsSPL13 positively regulates cell size in the grain hull resulting in enhanced grain length and yield (Si et al, 2016); OsSPL14 regulates plant architecture by controlling shoot branching during vegetative growth and panicle development (Jiao et al, 2010;Miura et al, 2010); and overexpression of OsSPL16 promoted cell proliferation and grain filling, resulting in increased grain width and yield (Wang et al, 2012). However, apart from bioinformatics and gene expression information (Zhang et al, 2014a;Wang et al, 2015), very little is known about the biological functions of SBP-box family members in common wheat. Ten wheat TaSPL genes have been cloned and classified into five groups (G1-G5; Zhang et al, 2014a).…”