The purpose of this work was to assess the impact of zearalenone (ZEN) and selected hormone regulators on the effectiveness of microspore embryogenesis in anther culture of wheat. The plant material comprised F1 hybrids of winter and spring wheat. Six combinations of media inducing microspore proliferation and formation of embryogenic structures were investigated: two combinations of growth regulators (D - 2,4-D + dicamba, K - 2,4-D + kinetin), each with three ZEN concentrations (0 mL/L, 0.1 mL/L, 0.2 mL/L). A significant increase in microspore embryogenesis effectiveness on media with the addition of ZEN was observed both at the stages of its induction and the formation of green plants in some genotypes. In case of both combinations of growth regulators, an increased concentration of ZEN resulted in more effective induction of microspore embryogenesis. The most effective induction medium was the D medium supplemented with 0.2 mL/L ZEN. As a result of the use of zearalenone together with two combinations of growth regulators, all genotypes tested produced androgenic structures, which indicates the breakdown of genotypic recalcitrant in the analysed hybrids. In addition, green plants were obtained from 18 out of 19 tested hybrids. The addition of ZEN to the medium did not affect the number of regenerated albino plants nor the number of spontaneous genome doublings proportion.

Plants have developed a variety of mechanisms and regulatory pathways to change their gene expression profiles in response to abiotic stress conditions and plant–microbe interactions. The plant–microbe interaction can be pathogenic or beneficial. Stress conditions, both abiotic and pathogenic, negatively affect the growth, development, yield and quality of plants, which is very important for crops. In contrast, the plant–microbe interaction could be growth-promoting. One of the proteins involved in plant response to stress conditions and plant–microbe interactions is cyclophilin. Cyclophilins (CyPs), together with FK506-binding proteins (FKBPs) and parvulins, belong to a big family of proteins with peptidyl-prolyl cis-trans isomerase activity (Enzyme Commission (EC) number 5.2.1.8). Genes coding for proteins with the CyP domain are widely expressed in all organisms examined, including bacteria, fungi, animals, and plants. Their different forms can be found in the cytoplasm, endoplasmic reticulum, nucleus, chloroplast, mitochondrion and in the phloem space. They are involved in numerous processes, such as protein folding, cellular signaling, mRNA processing, protein degradation and apoptosis. In the past few years, many new functions, and molecular mechanisms for cyclophilins have been discovered. In this review, we aim to summarize recent advances in cyclophilin research to improve our understanding of their biological functions in plant defense and symbiotic plant–microbe interactions.

Aktywne formy białek powstają w wyniku translacji oraz zmian zachodzących w trakcie, bądź po tym procesie (fałdowanie, potranslacyjne modyfikacje, kierowanie do odpowiedniego przedziału komórkowego). Struktura przestrzenna białka uzależniona jest od jego sekwencji aminokwasowej co udowodnił Christian Anfinsen, który badając fałdowanie rybonukleazy A, skupił się na odzyskiwaniu aktywności zdenaturowanego enzymu w wyniku prowadzonego procesu renaturacji (nagroda Nobla w dziedzinie chemii w 1972 r. razem z Stanfordem Moore’em i Williamem H. Steinem). Fałdowanie polipeptydów stabilizowane jest i wspomagane przez dwie grupy białek, są to czaperony (nazywane również białkami opiekuńczymi) oraz izomerazy: disulfidoizomerazy (PDI, ang. protein disulfide isomerase, EC 5.3.4.1) i izomerazy peptydyloprolilowe (PPI, ang. peptidylprolyl isomerase EC 5.2.1.8). Czaperony asystują podczas fałdowania białek utrzymując ich stany przejściowe i zapobiegają tworzeniu nieprawidłowych struktur, natomiast izomerazy prowadzą izomeryzację wiązań dwusiarczkowych (PDI) i peptydyloprolilowych (PPI). Praca ta w całościpoświęcona jest charakterystyce cyklofilin, należących do rodziny PPI ze szczególnym uwzględnieniem ich funkcji w procesach związanych z regulacją i patogenezą.

Functional analysis of promoter sequences is important to understand the regulation of gene expression. This study aimed to investigate the promoter region of the Lupinus luteus cytoplasmic cyclophilin gene (LlCyP; AF178458). After bioinformatic analysis, four promoter deletion fragments were fused to the β-glucuronidase reporter gene. We used Lotus japonicus as a model plant. After Agrobacterium rhizogenes transformation of L. japonicus, only the longest promoter region (−1055 bp to ATG) supported the β-glucuronidase expression in root nodule parenchyma. Putative cis-elements located between −1055 and −846 bp were subjected to site-directed mutagenesis. Mutations incorporated in the TGATT and AGATT motifs (cytokinin response) abolished GUS expression in nodules, but the mutated AAAGAT motif (OSE, organ-specific element) still activated the GUS expression in root nodules, mainly in cells surrounding the vascular bundle. Promoter deletion and mutation experiments suggest that cis-elements responsible for gene expression in the nodule are located in the region spanning from −1055 to −846 bp. We constructed a deletion fragment, in which the DNA sequence located between −822 and −198 bp was removed (pCYPMG). The promoter region arranged in the pCYPMG supports the expression in the parenchyma of L. japonicus nodules, but it is lower than the whole promoter region. The obtained results may be useful for transgene expression in determinate and indeterminate root nodules.

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