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The cereal cyst nematode (Heterodera latipons) is becoming an economically important species in global cereal production as it is being identified in many new cereal cultivated areas and causes significant losses. Consequently, understanding its biology becomes crucial for researchers in identifying its vulnerabilities and implementing effective control measures. In the current study, different morphological and biochemical changes of H. latipons cysts containing eggs with infective juveniles from a barley field in Jordan were studied during the summer of 2021, at two sample dates. The first, at the harvest of the cereal crop (June 2021), when the infective second-stage juveniles (J2s) were initiating diapause, and the second, before planting the sequent cereal crop (late October 2021), when the J2s were ending diapause. The studied population was characterized morphologically and molecularly, showing 98.4% molecular similarity to both JOD from Jordan and Syrian "300" isolates of H. latipons. The obtained results and observations revealed that there were dramatic changes in all the investigated features of the cysts and eggs they contained. Morphological changes such as cyst color, sub-crystalline layer, and thickness of the rigid eggshell wall were observed. A slight change in the emergence time of J2s from cysts was observed without any difference in the number of emerged J2s. The results of biochemical changes showed that the total contents of carbohydrates, glycogen, trehalose, glycerol, and protein were higher in cysts collected in October when compared to those cysts collected in June. The SDS-PAGE pattern indicated the presence of a protein with the size of ca. 100 kDa in both sampling dates, whereas another protein (ca. 20 kDa) was present only in the cysts of October. Furthermore, the expression of trehalase (tre) gene was detected only in H. latipons collected in October. The outcomes of this study provide new helpful information that elucidates diapause in H. latipons and may be used for the implementation of new management strategies of cyst nematodes. [ABSTRACT FROM AUTHOR]

Coumarins are a specific type of secondary metabolite that can be found in many plants. These compounds are predominantly produced through the phenylpropanoid pathway. Coumarins have been proven to possess a range of biological activities, including antimicrobial properties and antioxidant functions that aid in plant disease resistance response. The antimicrobial effect of coumarins is achieved through various mechanisms. They disrupt the cell membranes of pathogens, inhibit enzymatic activity, and hinder nucleic acid synthesis. Additionally, coumarins stimulate plant defense responses by triggering the production of reactive oxygen species (ROS) and activating the expression of immunity-related genes and signaling pathways such as the salicylic acid-dependent pathway. Due to their crucial role in defense mechanisms, coumarins can be effectively used in sustainable agriculture practices that emphasize environmentally friendly integrated pest management strategies. By providing a comprehensive overview of the biosynthetic pathways, mode of action, and application of coumarins in plant defense, this review aims to highlight the potential importance of coumarins in developing safe and sustainable crop protection strategies. [Display omitted] • Coumarins, a class of aromatic organic compounds widely distributed across the plant kingdom. • They play essential roles in plant defense mechanisms, particularly against microbial pathogens. • Coumarins exert antifungal activity through various mechanisms, disrupting fungal cell processes and inhibiting growth. • Coumarins also possess antiviral properties, enhancing the plant's natural immune response against viral infections. • Coumarins exhibit their antiviral effects on plant cells by leveraging their antioxidant and anti-inflammatory properties. [ABSTRACT FROM AUTHOR]