Latex, a sticky emulsion produced by specialized cells called laticifers, is a crucial part of a plant’s defense system against herbivory and pathogens. It consists of a broad spectrum of active compounds, which are beneficial not only for plants, but for human health as well, enough to mention the use of morphine or codeine from poppy latex. Here, we reviewed latex’s general role in plant physiology and the significance of particular compounds (alkaloids and proteins) to its defense system with the example of Chelidonium majus L. from the poppy family. We further attempt to present latex chemicals used so far in medicine and then focus on functional studies of proteins and other compounds with potential pharmacological activities using modern techniques such as CRISPR/Cas9 gene editing. Despite the centuries-old tradition of using latex-bearing plants in therapies, there are still a lot of promising molecules waiting to be explored.

To study genetic variations between genomes of plants that are naturally tolerant and sensitive to glyphosate, we used two Zea mays L. lines traditionally bred in Poland. To overcome the complexity of the maize genome, two sequencing technologies were employed: Illumina and Single Molecule Real-Time (SMRT) PacBio. Eleven thousand structural variants, 4 million SNPs and approximately 800 thousand indels differentiating the two genomes were identified. Detailed analyses allowed to identify 20 variations within the EPSPS gene, but all of them were predicted to have moderate or unknown effects on gene expression. Other genes of the shikimate pathway encoding bifunctional 3-dehydroquinate dehydratase/shikimate dehydrogenase and chorismate synthase were altered by variants predicted to have a high impact on gene expression. Additionally, high-impact variants located within the genes involved in the active transport of glyphosate through the cell membrane encoding phosphate transporters as well as multidrug and toxic compound extrusion have been identified.

DNA methylation plays a crucial role in the regulation of gene expression, activity of transposable elements, defense against foreign DNA, and inheritance of specific gene expression patterns. The link between stress exposure and sequence-specific changes in DNA methylation was hypothetical until it was shown that stresses can induce changes in the gene expression through hypomethylation or hypermethylation of DNA. To detect changes in DNA methylation under herbicide stress in two local Zea mays inbred lines exhibiting differential susceptibility to Roundup®, the methylation-sensitive amplified polymorphism (MSAP) technique was used. The overall DNA methylation levels were determined at approximately 60% for both tested lines. The most significant changes were observed for the more sensitive Z. mays line, where 6 h after the herbicide application, a large increase in the level of DNA methylation (attributed to the increase in fully methylated bands (18.65%)) was noted. DNA sequencing revealed that changes in DNA methylation profiles occurred in genes encoding heat shock proteins, membrane proteins, transporters, kinases, lipases, methyltransferases, zinc-finger proteins, cytochromes, and transposons. Herbicide stress-induced changes depended on the Z. mays variety, and the large increase in DNA methylation level in the sensitive line resulted in a lower ability to cope with stress conditions.

Soya bean [Glycine max (L.) Merr.] is an important legume crop with a significant worldwide production (Govindasamy et al., 2017), accounting for 340 million metric tons (mmt) in 2017. Exceptionally high protein (40%) and oil (20%) content make soya bean an outstanding source of nutrition that is used in a number of food products for humans, as well as in animal feeds. In addition, oil extracted from soya bean seeds can be used in the production of biofuels (Zhang, Pan, & Stellwag, 2008). All these benefits can be attributed to the symbiotic interaction of soya bean with Bradyrhizobium japonicum occurring in root nodules, which results in the fixation of atmospheric nitrogen (Zhang, Wang, et al., 2014). This cooperation benefits the environment by decreasing the need for the application of fertilizers and improving soil quality for subsequent crops, such as wheat or maize. In 2017, the production of soya bean in the European Union accounted for 2.74 mmt, which represented ~8% of the EU demand for soya bean seed, oil and meal. Simultaneously, the thriving animal production industry required the European Union to import over 33 mmt of soya bean products, mainly from Argentina and Brazil (https://www. idhsu stain ablet rade.com/uploa ded/2019/04/Europ ean-Soy-Monit or.pdf). The high demand for soya bean-derived products and difficult environmental conditions in temperate climates of the Northern and Central Europe, due to cold springs and early summer droughts,

Chilling stress is one of the most important factors limiting soybean yield in the temperate climate. It significantly constraints the spatial distribution and agricultural productivity of plants, thereby affecting their growth and development. In this study, to determine the involvement of microRNAs (miRNAs) and their target genes in the chilling resistance of four soybean cultivars (Augusta, Fiskeby V, Toyomusume and Glycine soja) with varying stress susceptibility, 72 small RNA libraries and 24 degradome libraries for high‐throughput sequencing were constructed. A total of 321 known miRNAs were identified, and 348 novel miRNAs were predicted in three analysed tissues. Moreover, under stress conditions, the differential expression of 162 known miRNAs, including well‐conserved, legume‐ and soybean‐specific miRNAs and 18 novel miRNAs, was found in the four tested cultivars. Degradome analysis allowed to assign the differentially expressed miRNAs to their potential target genes. They were found to be related to plant abiotic stress response mechanisms such as reactive oxygen species scavenging, flavonoid biosynthesis and regulation of osmotic potential based on GO and KEGG annotations. The findings of this study constitute a valuable insight into the function of miRNAs in the chilling resistance of soybean and may provide crucial knowledge in the development of new cultivars.