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Calmodulin (CaM) and calmodulin-like (CML) genes are widely involved in plant growth and development and mediating plant stress tolerance. However, the whole genome scale studies about CaM and CML gene families have not been done in wheat, and the possible functions of most wheat CaM/CML gene members are still unknown. In this study, a total of 18 TaCaM and 230 TaCML gene members were identified in wheat genome. Among these genes, 28 TaCaM/CML gene members have 74 duplicated copies, while 21 genes have 48 transcript variants, resulting in 321 putative TaCaM/CML transcripts totally. Phylogenetic tree analysis showed that they can be classified into 7 subfamilies. Similar gene structures and protein domains can be found in members of the same gene cluster. The TaCaM/CML genes were spread among all 21 chromosomes with unbalanced distributions, while most of the gene clusters contained 3 homoeologous genes located in the same homoeologous chromosome group. Synteny analysis showed that most of TaCaM/CMLs gene members can be found with 1–4 paralogous genes in T. turgidum and Ae. Tauschii. High numbers of cis-acting elements related to plant hormones and stress responses can be observed in the promoters of TaCaM/CMLs. The spatiotemporal expression patterns showed that most of the TaCaM/TaCML genes can be detected in at least one tissue. The expression levels of TaCML17, 21, 30, 50, 59 and 75 in the root or shoot can be up-regulated by abiotic stresses, suggesting that TaCML17, 21, 30, 50, 59 and 75 may be related with responses to abiotic stresses in wheat. The spatiotemporal expression patterns of TaCaM/CML genes indicated they may be involved widely in wheat growth and development. Our results provide important clues for exploring functions of TaCaMs/CMLs in growth and development as well as responses to abiotic stresses in wheat in the future.

Wheat-rye T1BL·1RS translocation lines are widely used, especially in China, but their processing quality is generally poor. An interfering expression vector targeting the ω-secalin genes was constructed with the 1Bx7 seed-specific promoter. Biolistic-mediated genetic transformation of the wheat cultivar KN199 carrying the T1BL·1RS translocation generated 10 transgenic lines. Two representative transgenic lines, 8-2 and 13-7, were selected for analysis. Compared with the control, the two transformants showed an up to 4.5-fold decrease in total ω-secalins and various levels of decrease in ω-gliadins, γ-gliadins, and low-molecular-weight glutenins. A decrease in high molecular weight (HMW) glutenin 1Bx7 was detected only in 8-2, owing possibly to promoter methylation. Increased levels of α-gliadins were observed in both transformants, but increased levels of HMW glutenins were observed only in 13-7. Line 13-7 showed increases in gluten index, Zeleny sedimentation value, stabilization time, and maximum resistance. Its bread volume was 849.6 mL, an 11.9% increase over that of the control. Line 8-2 showed decreases in these parameters, but its total cake-making quality score was 88, an 17.3% increase over that of the control. The study demonstrates that the same RNAi construct may produce different effects on wheat processing quality and highlights the influence of the vector promoter in RNA interference.

Numerous CCT genes are known to regulate various biological processes, such as circadian rhythm regulation, flowering, light signaling, plant development, and stress resistance. The CCT gene family has been characterized in many plants but remains unknown in the major cereal wheat (Triticum aestivum L.). Extended exposure to low temperature (vernalization) is necessary for winter wheat to flower successfully. VERNALIZATION2 (VRN2), a specific CCT-containing gene, has been proved to be strongly associated with vernalization in winter wheat. Mutation of all VRN2 copies in three subgenomes results in the eliminated demands of low temperature in flowering. However, no other CCT genes have been reported to be associated with vernalization to date. The present study screened CCT genes in the whole wheat genome, and preliminarily identified the vernalization related CCT genes through expression analysis. 127 CCT genes were identified in three subgenomes of common wheat through a hidden Markov model-based method. Based on multiple alignment, these genes were grouped into 40 gene clusters, including the duplicated gene clusters TaCMF6 and TaCMF8, each tandemly arranged near the telomere. The phylogenetic analysis classified these genes into eight groups. The transcriptome analysis using leaf tissues collected before, during, and after vernalization revealed 49 upregulated and 31 downregulated CCT genes during vernalization, further validated by quantitative real-time PCR. Among the differentially expressed and well-investigated CCT gene clusters analyzed in this study, TaCMF11, TaCO18, TaPRR95, TaCMF6, and TaCO16 were induced during vernalization but decreased immediately after vernalization, while TaCO1, TaCO15, TaCO2, TaCMF8, and TaPPD1 were stably suppressed during and after vernalization. These data imply that some vernalization related CCT genes other than VRN2 may exist in wheat. This study improves our understanding of CCT genes and provides a foundation for further research on CCT genes related to vernalization in wheat.

High-molecular-weight glutenin subunits (HMW-GSs) encoded by alleles at the Glu-A1, Glu-B1, and Glu-D1 loci confer unique end-use quality properties of common wheat (Triticum aestivum L.). Wheat accessions with the high-quality HMW-GSs combination of Ax2*/Bx7OE/Dx5 usually exhibit strong gluten characteristics. In order to stack these three high-quality subunit genes by molecular markers in strong gluten wheat breeding, an agarose gel-based multiplex PCR marker for these high-quality HMW-GSs and two agarose gel-based multiplex PCR markers detecting the homozygosity of Ax2* and Bx7OE subunits were developed. These markers were verified in an F2 segregating population from a cross between a medium-gluten winter wheat cultivar with the HMW-GSs combination of Ax null/Bx7 + By8/Dx4 + Dy12 and a strong-gluten spring wheat cultivar with the HMW-GSs combination of Ax2*/Bx7OE + By8*/Dx5 + Dy10. By integrating the newly established multiplex PCR markers and a published co-dominant PCR marker of the Dx5 subunit, a complete molecular marker selection system was established. After multiple rounds of molecular marker-assisted selection with the system, 17 homozygous winter wheat lines that stacked the three high-quality HMW-GSs were generated. The gluten strength of these homozygous lines was comparable to their strong-gluten parent, but significantly higher than that of their medium-gluten parent by measuring their lactic acid-sodium dodecyl sulfate solvent retention capacities of whole wheat meal. The multiplex PCR systems established in the present study can be used for molecular marker-assisted selection of strong gluten wheats.

[Objectives] The effect of acetosyringone seed soaking on the transformation of maize seed buds was analyzed, so as to improve the genetic transformation efficiency of maize and to provide technical support for transgenic breeding of maize. [Methods] The seeds of the "Zheng 58" maize inbred line were used as experimental materials. When the seeds were germinated, AS was added to the water at concentrations of 70, 140, 210, and 280 µ mol/L, respectively, and the seeds germinated without the addition of AS served as the CK. The Agrobacterium-mediated method was used to transform bud growth points of maize seeds, and green fluorescent protein detection was performed on the young shoots transformed with EGFP (enhanced green fluorescent protein) gene. The effect of soaking seeds with acetosyringone solution on the transformation of maize bud growth points by Agrobacterium was studied according to the detection results. [Results] Soaking seeds in acetosyringone solutions for germination had the effect of inhibiting the germination of maize seeds and inhibiting sprout elongation, and the higher the concentration of acetosyringone, the stronger the inhibition. When the concentration of acetosyringone solution was 280 µ mol/L, the germination rate of seeds was only 36.2% of the CK, while soaking seeds with 70-140 µ mol/L acetosyringone solution for germination could not only ensure a higher germination rate of maize seeds, but also significantly increased the transformation efficiency of maize bud growth points. When the seeds were soaked with 70 µ mol/L acetosyringone solution for germination, the positive rate of transformed maize buds was the highest, reaching 32.1%. [Conclusions] When maize bud growth points were used as the receptor of Agrobacterium transformation, soaking seeds with 70-140 µ mol/L acetosyringone for germination basically did not affect the germination of seeds, and was beneficial to the activation of Agrobacterium, thereby promoting the transformation. [ABSTRACT FROM AUTHOR]

[Objectives] This study was conducted to improve the efficiency of genetic transformation using growing points of com sprouts. [Methods] A mixed liquid of plant hormones 6-BA and KT at a suitable concentration and ratio was added dropwise to the growing points of corn sprouts, followed by culture under appropriate conditions. [Results] Com sprouts could be induced to form multiple plants, thereby improving the transformation efficiency of glowing points in corn sprouts. [Conclusions J This study provides a breeding method using growing points of corn sprouts as transformation receptors for direct plantlet formation without tissue culture by the Agrobacterium transgenic technology. [ABSTRACT FROM AUTHOR]

[ Objectives] This study was conducted to improve the genetic transformation rate of maize. [ Methods] The seeds of maize " Zheng 58" as the experimental material were germinated and treated under freezing temperature of -18 °C for 30 and 35 min. The EGFP gene was transformed into the growth points of these seed buds by Agrobacterium tumefaciens EHA105. The transformation effect was determined by fluorescence protein detection on transformed buds. [Results] After a certain period of treatment at --18 °Ct following germination and transformation of maize bud growth points with A. tumefaciens, although the survival rate of maize buds was reduced, the percentage of transformed cells significantly increased. [ Conclusions] Low temperature treatment can improve the transformation efficiency of A. tumefaciens to the growth point of maize bud. [ABSTRACT FROM AUTHOR]