Genome-wide identification and expression analysis of the calmodulin-binding transcription activator (CAMTA) gene family in wheat (Triticum aestivum L.).

BACKGROUND: Plant calmodulin-binding transcription activator (CAMTA) proteins play important roles in hormone signal transduction, developmental regulation, and environmental stress tolerance. However, in wheat, the CAMTA gene family has not been systematically characterized. RESULTS: In this work, 15 wheat CAMTA genes were identified using a genome-wide search method. Their chromosome location, physicochemical properties, subcellular localization, gene structure, protein domain, and promoter cis-elements were systematically analyzed. Phylogenetic analysis classified the TaCAMTA genes into three groups (groups A, B, and C), numbered 7, 6, and 2, respectively. The results showed that most TaCAMTA genes contained stress-related cis-elements. Finally, to obtain tissue-specific and stress-responsive candidates, the expression profiles of the TaCAMTAs in various tissues and under biotic and abiotic stresses were investigated. Tissue-specific expression analysis showed that all of the 15 TaCAMTA genes were expressed in multiple tissues with different expression levels, as well as under abiotic stress, the expressions of each TaCAMTA gene could respond to at least one abiotic stress. It also found that 584 genes in wheat genome were predicted to be potential target genes by CAMTA, demonstrating that CAMTA can be widely involved in plant development and growth, as well as coping with stresses. CONCLUSIONS: This work systematically identified the CAMTA gene family in wheat at the whole-genome-wide level, providing important candidates for further functional analysis in developmental regulation and the stress response in wheat.

Transcriptome analysis of activated charcoal-induced growth promotion of wheat seedlings in tissue culture.

BACKGROUND: Activated charcoal (AC) is highly adsorbent and is often used to promote seedling growth in plant tissue culture; however, the underlying molecular mechanism remains unclear. In this study, root and leaf tissues of 10-day-old seedlings grown via immature embryo culture in the presence or absence of AC in the culture medium were subjected to global transcriptome analysis by RNA sequencing to provide insights into the effects of AC on seedling growth. RESULTS: In total, we identified 18,555 differentially expressed genes (DEGs). Of these, 11,182 were detected in the roots and 7373 in the leaves. In seedlings grown in the presence of AC, 9460 DEGs were upregulated and 7483 DEGs were downregulated in the presence of AC as compared to the control. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed 254 DEG-enriched pathways, 226 of which were common between roots and leaves. Further analysis of the major metabolic pathways revealed that AC stimulated the expression of nine genes in the phenylpropanoid biosynthesis pathway, including PLA, CYP73A, COMT, CYP84A, and 4CL, the protein products of which promote cell differentiation and seedling growth. Further, AC upregulated genes involved in plant hormone signaling related to stress resistance and disease resistance, including EIN3, BZR1, JAR1, JAZ, and PR1, and downregulated genes related to plant growth inhibition, including BKI1, ARR-B, DELLA, and ABF. CONCLUSIONS: Growth medium containing AC promotes seedling growth by increasing the expression of certain genes in the phenylpropanoid biosynthesis pathway, which are related to cell differentiation and seedling growth, as well as genes involved in plant hormone signaling, which is related to resistance.

Homoeologous cloning of omega-secalin gene family in a wheat 1BL/1RS translocation.

Wheat 1BL/1RS translocations are widely planted in China as well as in most of the wheat producing area in the world for their good qualities of disease resistance and high yield. 1BL/1RS translocations are however poor in bread making, partially caused by a family of small monomeric proteins, omega-secalins, which are encoded by genes on 1RS. Based on published sequence of a rye omega-secalin gene we designed a pair of primers to cover the whole mature protein coding sequence. A major band could be amplified from 1BL/1RS translocations but not from euploid wheat. Using this primer set we conducted PCR amplification by using high fidelity Pfu polymerase on the genomic DNAs and cDNAs purified from a 1BL/1RS translocation Lankao 906. Sequencing analysis indicated that this gene family contains several members of 1150 bp, 1076 bp, 1075 bp, 1052 bp and 1004 bp genes, including two pseudogenes and three active genes. The gene transcripts were differentially expressed in developing seeds.