Identification and characterization of the 14-3-3 gene family in switchgrass.

Members of the 14-3-3 family of proteins are conserved regulatory proteins that are widely found in eukaryotes and play crucial roles in diverse physiological processes, including responses to different stresses. Although genome-wide analysis of 14-3-3 proteins has been performed in a few plant species, it has not been performed in switchgrass. In this study, we identified 21 switchgrass 14-3-3 proteins (designated PvGF14a to PvGF14u) and examined genes for improved stress tolerance in this species. A phylogenetic tree was constructed to demonstrate that PvGF14 proteins can be divided into six groups, and that PvGF14 proteins belonging to each class exhibit similar gene structure. A phylogenetic analysis of PvGF14 proteins among switchgrass, Arabidopsis, and rice was conducted. Ten PvGF14 proteins were found to be orthologous to several abiotic stresses, and these were particularly responsive proteins in Arabidopsis and rice. Tissue-specific expression profiles showed that PvGF14a, PvGF14k, PvGF14l, and PvGF14m may play significant roles in the regulation of lignin metabolism, and that PvGF14r may participate in flower development. Taken together, these data suggest that PvGF14 proteins may be involved in various biosynthesis.

Orthogonal design in the optimization of a start codon targeted (SCoT) PCR system in Roegneria kamoji Ohwi.

Roegneria kamoji Ohwi is an excellent forage grass due to its high feeding value and high resistance to some biotic and abiotic stresses. However, the start codon targeted (SCoT) polymorphism has not been conducted on R. kamoji. In this study, an orthogonal L16 (45) design was employed to investigate the effects of five factors (Mg2+, dNTPs, Taq DNA polymerase, primer, and template DNA) on the polymerase chain reaction (PCR) to determine the optimal SCoT-PCR system for R. kamoji. The results showed that the most suitable conditions for SCoT-PCR in R. kamoji included 1.5 mM Mg2+, 0.15 mM dNTPs, 1.0 U Taq DNA polymerase, 0.4 pM primer, and 40 ng template DNA. SCoT primers 39 and 41 were used to verify the stability of the optimal reaction system, and amplification bands obtained from diverse samples were found to be clear, rich, and stable in polymorphisms, indicating that this reaction system can be used for SCoT-PCR analysis of R. kamoji. We have developed a simple and rapid way to study the mutual effects of factors and to obtain positive results through the use of an orthogonal design L16 (45) to optimize the SCoT-PCR system. This method may provide basic information for molecular marker-assisted breeding and analyses of genetic diversity in R. kamoji.