'Mexican' lime (Citrus aurantifolia Swingle) was transformed with constructs that contained chimeric promoter-gus gene fusions of phloem-specific rolC promoter of Agrobacterium rhizogenes, Arabidopsis thaliana sucrose-H(+) symporter (AtSUC2) gene promoter of Arabidopsis thaliana, rice tungro bacilliform virus (RTBV) promoter and sucrose synthase l (RSs1) gene promoter of Oryza sativa (rice). Histochemical β-glucuronidase (GUS) analysis revealed vascular-specific expression of the GUS protein in citrus. The RTBV promoter was the most efficient promoter in this study while the RSs1 promoter could drive low levels of gus gene expression in citrus. These results were further validated by reverse transcription real-time polymerase chain reaction and northern blotting. Southern blot analysis confirmed stable transgene integration, which ranged from a single insertion to four copies per genome. The use of phloem-specific promoters in citrus will allow targeted transgene expression of antibacterial constructs designed to battle huanglongbing disease (HLB or citrus greening disease), associated with a phloem-limited Gram-negative bacterium.

Honey is a natural sweetener composed mostly of sugars, but it contains also pollen grains, proteins, free amino acids, and minerals. The amounts and proportions of these components depend on the honey type and bee species. Despite the low content of honey protein, they are becoming a popular study object, and have recently been used as markers of the authenticity and quality of honey. Currently, the most popular methods of protein isolation from honey are dialysis against distilled water, lyophilization of dialysate, or various precipitation protocols. In this work, we propose a new method based on saturated phenol. We tested it on three popular polish honey types and we proved its compatibility with both 1D and 2D polyacrylamide gel electrophoresis (PAGE) and MS (mass spectrometry) techniques. The elaborated technique is also potentially less expensive and less time-consuming than other previously described methods, while being equally effective.

Simple Summary: Snake venom is mostly composed of proteins and peptides, which are of interest to many researchers due to their potential pharmacological properties. Due to their biochemical character, these components are analyzed using proteomic techniques such as electrophoresis, chromatography and mass spectrometry. A very important stage of such studies is the measurement of protein concentration in the sample, which is most often performed by colorimetric methods. In the presented article, we used five such techniques on venoms of two snake species, namely Agkistrodon contortrix and Naja ashei. In the case of A. contortrix venom, four methods provide similar concentration values, whereas, in the case of N. ashei, the differences between results are very significant. The source of these differences should probably be seen in the differences in amino acid composition of proteins of these two venoms. With this report, we would like to draw attention to the need to select an appropriate method for measuring the concentration of protein in the venom, especially in the case of Elapid species.Abstract: Snake venom is an extremely interesting natural mixture of proteins and peptides, characterized by both high diversity and high pharmacological potential. Much attention has been paid to the study of venom composition of different species and also detailed analysis of the properties of individual components. Since proteins and peptides are the active ingredients in venom, rapidly developing proteomic techniques are used to analyze them. During such analyses, one of the routine operations is to measure the protein concentration in the sample. The aim of this study was to compare five methods used to measure protein content in venoms of two snake species: the Viperids representative, Agkistrodon contortrix, and the Elapids representative, Naja ashei. The study showed that for A. contortrix venom, the concentration of venom protein measured by four methods is very similar and only the NanoDrop method clearly stands out from the rest. However, in the case of N. ashei venom, each technique yields significantly different results. We hope that this report will help to draw attention to the problem of measuring protein concentration, especially in such a complex mixture as animal venoms.

Main conclusion Changes in proteome level as a result of methyl jasmonate and cholesterol treatment were investigated. The identified proteins were often involved in response to stress caused by various treatments. Furthermore, 18 proteins were expressed in treatmentspecific manner. In this study, the fenugreek plants were treated with methyl jasmonate (as an elicitor) and cholesterol (as a precursor of steroids and steroidal saponins) to check reaction at the level of the proteome to stress and to investigate steroidal saponin (diosgenin) biosynthesis. Proteins were separated by two-dimensional electrophoresis (2-DE) and identified by MALDI-ToF/ToF followed by database searches using Mascot search engine. Totally, 63 and 41 protein spots were differentially expressed after methyl jasmonate and cholesterol treatment, respectively. These proteins were classified into seven groups: photosynthesis, energy, metabolism, protein metabolism, secondary metabolism, stress and defense, and other. We found that 9 proteins were responsive to all treatments, and 18 proteins expressed in treatment-specific manner. Higher level of photosynthetic proteins sensitive to both biotic and abiotic stimuli was detected. In addition, proteins related to the stress (especially oxidative) and defense, protein, and secondary metabolism were overexpressed. The results indicate that methyl jasmonate and cholesterol elicited a defense reaction at the proteome level as a response to stress. The usefulness of 2-DE method for identification of proteins related with species-specific metabolic pathways is restricted. Integration of transcriptome data with proteomic analysis improved annotation process.