Tomato is an economically important vegetable crop which is attacked heavily by insect pests leading to reduction of yield and quality of the fruits. Field experiments were carried out to investigate the dissipation of methomyl (a common insecticide) used mainly on tomato fruits. LC-MS/MS coupled with the QuEChERS method were used for the determination of methomyl. The results showed that the recovery using matrix-matched standards ranged from 87.8 to 101.3%, with relative standard deviation of 2.5 to 7.5%. Kinetics equation, Log R = log R0 – 0.434 Kt, was used to calculate the rate of degradation in tomato, soil and water. Residue half-life calculated using kinetic rate ranged from 1.95 to 1.63 days in tomato and soil, respectively. From the results it was concluded that tomato fruits can be safely harvested for consumption after 15 days of application based on estimated preharvest interval (PHI). It is advisable to re-estimate the PHI regularly owing to data from the EU and Codex.
To keep genetic diversity, flowering plants have developed a self-incompatibility system, which can prevent self-pollination.
It has been reported that calcium concentration in pistil papilla cells was increased after self-pollination
in transformed self-incompatible Arabidopsis thaliana. In this study, we found that CML27 changed its expression
level for both mRNA and protein when compared to transcriptome and proteome. At the same time, CML27 was
expressed in the anther and pistil at a high level and reached up to 5-fold up-regulated expression in the pistil
at 1 h post-pollination when compared to 0 min. In order to find out potential proteins that may interact with
BoCML27, BoCML27 was expressed in and isolated from E. coli. After its co-incubation with Brassica oleracea
pistil proteins, the products were separated on SDS-PAGE gels. We found a specific band at the position between
130–180 kDa. Through LC-MS-MS (Q-TOF) analysis, eight proteins were identified from the band. The proteins
include 26S proteasome non-ATPase regulatory (26S), Phospholipase D, alpha 2 (PLDα2) involved in Ca2+ binding
and Coatomer subunit alpha-2-like (Coatomer) involved in vesicle mediated transport. All of these identified
proteins provide new insights for the self-incompatibility response in B. oleracea, specific for increasing Ca2+
concentration in pistil papilla cells.
This work presents a comparative analysis of the phenolic composition (UHPLC-PDA-ESI-MS3, HPLC-PDAfingerprint, UV-spectrophotometric methods) and antioxidant activity (DPPH, FRAP) of leaf samples from two vegetation seasons of a medicinal and dietary plant Sorbus domestica growing in its natural habitat (Croatia, C) and cultivated in Poland (P). The samples from both sources were rich in structurally diverse polyphenols (44 analytes; P: 73.4–76.6 and C: 98.3–106.7 mg GAE/g dry leaves) including the dominating flavan-3-ols and flavonoids. The greatest qualitative and quantitative differences were observed for flavonoids (P: 14.3–20.3%; C: 27.5–34.1% of polyphenols) – in the Polish samples flavonoid diglycosides predominated, in the Croatian samples the contents of both monoglycosides and diglycosides were similar. In the case of dry methanolic extracts, despite the higher extraction efficiency obtained for the Croatian samples (32–36% vs 23–24%), the quality of the extracts was comparable, both in terms of the total phenolic content (P: 269.4–280.0; C: 297.6–304.4; mg GAE/g dry extract) and antioxidant activity parameters (DPPH, EC50, μg/mL. P: 10.5–10.9, C: 10.0–10.3; and FRAP, mmol Fe2+/g, P: 6.64–7.13, C: 7.06–7.11). As a result, the study confirmed the influence of environmental conditions on the phenolic profile and antioxidant capacity of S. domestica leaves, as well as showed that despite some differences, plant materials from both Poland and Croatia might be suitable for production of natural health products.