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Apis cerana cerana triosephosphate isomerase ( AccTPI), a key regulatory enzyme in glycolysis and gluconeogenesis pathway, catalyzes the interconversion of glyceraldehyde 3-phosphate to dihydroxyacetone phosphate. However, its role in A. cerana cerana has not been completely clarified. In this study, a TPI gene was cloned from A. cerana cerana and named AccTPI. The open reading frame (ORF) of AccTPI is 744 bp, which encodes 247 amino acids with a predicted molecular weight and an isoelectric point of 26.8 kDa and 8.42, respectively. The expression of AccTPI was up-regulated by some abiotic stresses, while it was down-regulated by HgCl, ultraviolet light (UV), and vitamin C (VC) treatment. Finally, a disc diffusion assay revealed that recombinant AccTPI proteins can protect cells from oxidative stresses. Taken together, all of the results indicate that AccTPI may play an important role in the metabolism, in antioxidant defense, and in many biological functions in the growth and development of A. cerana cerana. [ABSTRACT FROM AUTHOR]

Key message: Our results indicate that overexpression of the GhWRKY39 - 1 gene enhances resistance to pathogen infection and tolerance to high salt and oxidative stress in transgenic Nicotiana benthamiana. Abstract: WRKY transcription factor genes play significant roles in the response to biotic and abiotic stresses. Cotton ( Gossypium hirsutum) is an important fiber and oil crop worldwide. We isolated and characterized GhWRKY39- 1, which is a group IId WRKY gene that is present as a single copy in the cotton genome. Quantitative PCR analyses indicated that GhWRKY39- 1 was induced by pathogen infection, defense-related signaling molecules, and abiotic stresses, such as NaCl and methyl viologen. An analysis of the subcellular localization of the GhWRKY39-1 protein indicated that it localized to the nucleus. Furthermore, constitutive overexpression of GhWRKY39- 1 in Nicotiana benthamiana conferred a greater resistance to infection by both the bacterial pathogen Ralstonia solanacearum and the fungal pathogen Rhizoctonia solani. The transgenic plants also exhibited elevated mRNA levels of several pathogen-related ( PR) genes, including PR1c, PR2 and PR4. Moreover, transgenic plants displayed an enhanced tolerance to salt and oxidative stress and elevated expression of several oxidation-related genes, including APX, CAT, GST and SOD. Overall, these results indicate that GhWRKY39- 1 functions as a positive regulator of plant defense against pathogen infection and responses to salt stress and reactive oxygen species. [ABSTRACT FROM AUTHOR]

RNA-dependent RNA polymerases (RDRs) play key roles in RNA silencing, developmental regulation, antiviral defense and the maintenance of genome integrity. In this work, we isolated an RDR gene ( NtRDR6) from Nicotiana tabacum using reverse-transcription PCR (RT-PCR) and rapid amplification of cDNA ends PCR (RACE-PCR) technology. The full-length cDNA of NtRDR6 encodes a protein of 1,197 amino acids, which contains all of the five highly conserved regions in plant RDRs and the DxDGD signature motif. An amino acid sequence alignment revealed that NtRDR6 shares a high level of similarity with other known RDRs. The genomic sequence of NtRDR6 contains two introns and a group of putative cis-acting elements in the 5′-flanking region. Expression analysis performed using 6-week-old seedlings revealed that the transcript level of NtRDR6 is up-regulated by diverse signalling molecules, including jasmonate (JA), abscisic acid (ABA), gibberellin A (GA) and salicylic acid (SA). The expression of NtRDR6 is also elevated markedly by Cucumber mosaic virus (CMV) and Potato virus X (PVX) but not by Potato virus Y (PVY) and Tobacco mosaic virus (TMV). Notably, abiotic stresses have alternative effects on the transcription of NtRDR6, with heat (37°C) significantly increasing the expression of NtRDR6, whereas low temperature (15°C) does not affect expression. These results indicated that NtRDR6 may be involved in several signal transduction pathways to defend against plant virus attack and in the response to abiotic stresses. [ABSTRACT FROM AUTHOR]