Overexpression of the Wild Soybean R2R3-MYB Transcription Factor GsMYB15 Enhances Resistance to Salt Stress and Helicoverpa Armigera in Transgenic Arabidopsis

Plant R2R3-MYB transcription factors (TFs) have been suggested to play crucial roles in the response to diverse abiotic and biotic stress factors but there is little molecular evidence of this role in soybean plants. In this work, we identified and functionally characterized an R2R3-MYB TF, namely, GsMYB15, from the wild soybean ED059. Protein and promoter sequence analysis indicated that GsMYB15 is a typical R2R3-MYB TF and contains multiple stress-related cis-elements in the promoter region. GsMYB15 is located in the nucleus and exhibits transcriptional activation activity. QPCR assays suggested that the expression of GsMYB15 could be induced by NaCl, insect attacks and defense-related hormones (MeJA and SA). Furthermore, GsMYB15 exhibited highest expression in pods compared to other tissues. Functional analysis of GsMYB15 demonstrated that overexpression of GsMYB15 could increase salt tolerance and enhance the resistance to H. armigera larvae in transgenic Arabidopsis plants. Moreover, overexpression of GsMYB15 also affected the expression levels of salt stress- and defense-related genes in the transgenic plants. Feeding with transgenic Arabidopsis plant leaves could significantly suppress the expression levels of immunity-related genes in H. armigera larvae. Overexpression of GsMYB15 also increased mesophyll cell levels in transgenic plants. Taken together, these results provide evidence that GsMYB15 is a positive regulator of salt stress tolerance and insect resistance in transformed Arabidopsis plants.

Genome-Wide Identification and Characterization of the GmSnRK2 Family in Soybean

Sucrose non-fermenting-1 (SNF1)-related protein kinase 2s (SnRK2s) that were reported to be involved in the transduction of abscisic acid (ABA) signaling, play important roles in response to biotic and abiotic stresses in plants. Compared to the systemic investigation of SnRK2s in Arabidopsisthaliana and Oryza sativa, little is known regarding SnRK2s in soybean, which is one of the most important oil and protein crops. In the present study, we performed genome-wide identification and characterization of GmSnRK2s in soybean. In summary, 22 GmSnRK2s were identified and clustered into four groups. Phylogenetic analysis indicated the expansion of SnRK2 gene family during the evolution of soybean. Various cis-acting elements such as ABA Response Elements (ABREs) were identified and analyzed in the promoter regions of GmSnRK2s. The results of RNA sequencing (RNA-Seq) data for different soybean tissues showed that GmSnRK2s exhibited spatio-temporally specific expression patterns during soybean growth and development. Certain GmSnRK2s could respond to the treatments including salinity, ABA and strigolactones. Our results provide a foundation for the further elucidation of the function of GmSnRK2 genes in soybean.

Neuronal nicotinic acetylcholine receptors in rat trigeminal ganglia

The application of nicotine to the various epithelia served by the trigeminal nerve produces irritation and/or pain by activating neuronal nicotinic acetylcholine receptors (NnAChRS) in sensory neurons. In this study the NnAChRs were identified in rat trigeminal ganglia (TG) using RT-PCR and immunocytochemistry. With RT-PCR the subunits of NnAChRs in rat TG were determined, and with immunocytochemistry the localization of three prominent subunits (alpha 7, alpha 4 and beta 2) were localized in intact TG neurons. The relative abundance of the alpha and beta subunits were: alpha 7 approximately alpha 3 > alpha 6 > alpha 4 approximately alpha 5 > alpha 9 > or = alpha 2, and beta 2 approximately beta 3 > beta 4. This is the first report of the alpha 9 subunit in TG. Immunohistochemical studies revealed that almost all TG neurons contained alpha 7-LI and alpha 4-LI, and that 85% had beta 2-LI. For these three subunits much of the label was internalized. Immunocytochemical studies using antibodies raised against chick alpha 8 subunits did not specifically label rat TG. These data reveal that rat TG neurons contain the entire spectrum of mammalian NnAChR subunits.