We studied a stimulatory effect of silver nitrate on callus formation and shoot regeneration of five oilseed rape commercial varieties Ability, Lagonda, Lancia, Menthal and Mirakel (Brassica napus L.). Hypocotyls were induced to organogenesis on the media supplemented with silver nitrate at concentration 5 mg.L1 and without silver nitrate as a control. After 2 weeks of cultivation, calli on the media with silver nitrate became deep green in colour. First shots appeared after 4 weeks of cultivation on the media with silver nitrate. Calli formed on the control media were pale green and did not form any shoots or at very low efficiency. Silver nitrate improved regeneration efficiency from 0- 0.8% to 8.3-10% in varieties Albina, Lancia and Menthal. Explants of Lagonda and Mirakel did not form any calli and these varieties appeared to be recalcitrant. Analyses of six weeks-old calli showed that silver nitrate increased concentration of photosynthetic pigments, which is a good prerequisite for cell regeneration. Silver nitrate increased malondialdehyde level and induced changes in enzyme activities of antioxidants ascorbate peroxidase and catalase; and in the accumulation of non-enzymatic antioxidant proline; in the genotype dependant manner. The results suggest that an activation of stress response was necessary to obtain shoots with higher frequency in the varieties Albina, Lancia and Menthal.

We conducted analyses on 253 protein sequences (Pfam00257) derived from 25 woody plant species, including trees, shrubs, and vines. Our goal was to gain insights into their architectural types, biochemical characteristics, and potential involvement in mitigating abiotic stresses, such as drought, cold, or salinity. The investigated protein sequences (253) comprised 221 angiosperms (85 trees/shrubs and 36 vines) and 32 gymnosperms. Our sequence analyses revealed the presence of seven architectural types: K_n, K_nS, SK_n, Y_nK_n, Y_nSK_n, FSK_n, and F_nK_n. The FSK_n type predominated in tree and shrub dehydrins of both gymnosperms and angiosperms, while the YnSKn type was more prevalent in vine dehydrins. The Y_nSK_n and Y_nK_n types were absent in gymnosperms. Gymnosperm dehydrins exhibited a shift towards more negative GRAVY scores and Fold Indexes. Additionally, they demonstrated a higher Lys content and lower His content. By analyzing promoter sequences in the angiosperm species, including trees, shrubs, and vines, we found that these dehydrins are induced by the ABA-dependent and light-responsive pathways. The presence of stress- and hormone-related cis-elements suggests a protective effect against dehydration, cold, or salinity. These findings could serve as a foundation for future studies on woody dehydrins, especially in the context of biotechnological applications.

Nearly 50 years has passed since brown spot of pear (BSP), caused by the fungus Stemphylium vesicarium, was detected in Europe. Despite significant progress in disease management and the identification of resistance targets in pear, BSP remains a major threat for European pear production. The extensive knowledge recently acquired on the biology, genomics and epidemiology of S. vesicarium , together with the increasing importance of this pathogen in Europe, prompted the preparation of this review to provide a comprehensive overview of its current geographic distribution, as well as newly discovered aspects of its biology, infection strategies and host specificity. This review also examines the symptoms and epidemiology of BSP, highlighting key factors influencing disease development, including spore dispersal and environmental conditions. The susceptibility of different pear cultivars is discussed, together with recent advances in genetic studies related to resistance breeding, providing guidance for future breeding programmes. In addition, publicly available genomic data for S. vesicarium are summarized to provide a foundation for identifying pathogenicity‐related characteristics. Finally, potential disease control strategies are outlined to offer new perspectives for the effective management of BSP.

The fungal genus Colletotrichum includes numerous important plant pathogenic species, some of which causes fruit bitter rot as well as leaf lesions (leaf black spot) on major crops, leading to yield losses (Fu et al. 2019; Talhinhas & Baroncelli, 2023). C. acutatum was reported associated with black spot on fallen, immature fruit of pear (Pyrus pyrifolia) in New Zealand (Damm et al. 2012); however, to our knowledge, this species has not been reported in Italy or nowhere else. In 2022, a significant increase of anthracnose symptoms was observed on pears in Emilia-Romagna region, Italy. Symptoms, such as round brown lesions of 1 to 4 cm, appeared on more than 50% of refrigerated stored fruit. These symptoms were undetectable at the end of September 2022 and appeared after a five-month period of storage (February 2023) at 4°C (e-Xtra 1A and B). Fungal isolates were obtained from symptomatic pears after surfaces sterilization with 96% ethanol by culturing necrotic tissue pieces on Potato Dextrose Agar at 25°C in the dark (e-Xtra 1C and D). Cultures were shades of coral color, from opalescent to sunkist coral, with slight aerial mycelium becoming grey and darker with age. When observed from the reverse side, the color was pink and, with age, became coral orange to dark amaranth. Conidia observed with a light microscope appeared hyaline and fusiform, 8 to 16 × 2.5 to 4 μm, with two pointed ends or one rounded end. (e-Xtra 1E) One reference isolate, named L51, was used for molecular characterization. Total genomic DNA was extracted, and the ITS region of rDNA amplified using the universal primers ITS1 and ITS4, then sequenced. The resulting sequences were 100% identical to those of C. acutatum (NR_144794.1: strain CBS 112996 ITS region; from TYPE material). Based on Damm et al. (2012), partial ACT, GAPDH, CHS and TUB2 gene sequences were also amplified and sequenced (GenBank Accession numbers: ITS: OR882016, ACT: OR882013, GAPDH: OR882011, CHS: OR882012, TUB2: OR882010), to characterize the isolates. Additionally, the multilocus phylogenetic analysis carried out with the obtained and reference sequences (Damm et al. 2012) revealed the species of analyzed isolates and confirmed the BLAST results, identifying the strain as C. acutatum (e-Xtra 1F). Koch's postulates were performed on 10 'Kaiser' pears. Surfaces sterilized fruits with 96% ethanol were subjected to wound inoculation with a conidial suspension (106 conidia ml-1) while 10 fruit were used as negative control and inoculated with sterile water. Following an incubation period of 8-14 days at 15-20°C, symptoms around the inoculation site resembled those initially observed, while the negative control showed no symptoms. Fungal colonies re-isolated from the lesions exhibited the same morphological characteristics as the original isolates. To our knowledge, this is the first report of pear bitter rot caused by C. acutatum in Italy and in Europe (Talhinhas & Baroncelli, 2023). Yet, bitter rot had not been recognized as a notable issue in pear cultivation. Nevertheless, given that pears rank as the 8th most cultivated fruit globally and economically very significant for the Emilia Romagna region in Italy the emergence of pear bitter rot caused by Colletotrichum species has the potential to evolve into a significant worldwide problem, warranting further investigation.