Comprehensive analyses of the annexin gene family in wheat

Abstract

BackgroundAnnexins are an evolutionarily conserved multigene family of calcium-dependent phospholipid binding proteins that play important roles in stress resistance and plant development. They have been relatively well characterized in model plants Arabidopsis (Arabidopsis thaliana) and rice (Oryza sativa), but nothing has been reported in hexaploid bread wheat (Triticum aestivum) and barely (Hordeum vulgare), which are the two most economically important plants.ResultsBased on available genomic and transcriptomic data, 25 and 11 putative annexin genes were found through in silico analysis in wheat and barley, respectively. Additionally, eight and 11 annexin genes were identified from the draft genome sequences of Triticum urartu and Aegilops tauschii, progenitor for the A and D genome of wheat, respectively. By phylogenetic analysis, annexins in these four species together with other monocots and eudicots were classified into six different orthologous groups. Pi values of each of Ann1–12 genes among T. aestivum, T. urartu, A. tauschii and H. vulgare species was very low, with the exception of Ann2 and Ann5 genes. Ann2 gene has been under positive selection, but Ann6 and Ann7 have been under purifying selection among the four species in their evolutionary histories. The nucleotide diversities of Ann1–12 genes in the four species were 0.52065, 0.59239, 0.60691 and 0.53421, respectively. No selective pressure was operated on annexin genes in the same species. Gene expression patterns obtained by real-time PCR and re-analyzing the public microarray data revealed differential temporal and spatial regulation of annexin genes in wheat under different abiotic stress conditions such as salinity, drought, cold and abscisic acid. Among those genes, TaAnn10 is specifically expressed in the anther but fails to be induced by low temperature in thermosensitive genic male sterile lines, suggesting that specific down-regulation of TaAnn10 is associated with conditional male sterility in wheat.ConclusionsThis study analyzed the size and composition of the annexin gene family in wheat and barley, and investigated differential tissue-specific and stress responsive expression profiles of the gene family in wheat. These results provided significant information for understanding the diverse roles of plant annexins and opened a new avenue for functional studies of cold induced male sterility in wheat.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-016-2750-y) contains supplementary material, which is available to authorized users.

Genome-Wide Identification and Expression Analysis of the HD-Zip Gene Family in Wheat (Triticum aestivum L.)

“…The availability of the complete genome sequence allowed the identification and analysis of gene family at the genome level in wheat. Increasing numbers of gene families such as MAPKKK, Aux/IAA and Annexin have been reported in wheat [ 34 , 62 , 63 ]. HD-Zip, as one of the plant-specific transcription factor gene families, is vital for regulating plant development and physiological processes as well as in response to abiotic stresses.…”

Calcium transport across plant membranes: mechanisms and functions

“…These are cytosolic proteins that are capable of Ca 2+ ‐dependent or Ca 2+ ‐independent association with membrane phospholipids (Lizarbe et al ., ; Konopka‐Postupolska & Clark, ) and are traditionally associated with the onset of Ca 2+ ‐dependent apoptosis in animal cells. Eight putative genes encoding annexins are found in Arabidopsis, and 25 and 11 genes were detected in wheat and barley, respectively (Xu et al ., ). Plant annexins differ structurally from their animal counterparts, consisting of repeated annexin domains with conserved endonexin fold binding Ca 2 + (Konopka‐Postupolska & Clark, ).…”

ROS-Activated Ion Channels in Plants: Biophysical Characteristics, Physiological Functions and Molecular Nature

“…However, in the presence of Ca 2+ , they are capable of association with membrane phospholipids and changing their characteristics of biomembranes. Eight putative genes encoding annexins have been identified in Arabidopsis thaliana , and 11 and 25 genes were found in barley and wheat, respectively [ 90 ]. Plant annexins consist of repeated annexin domains with a conserved endonexin fold binding Ca 2+ .…”