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Climate change (CC) conditions projected for many temperate areas of the world, expressed by way of excessive temperatures and low water availability, will impact forest health directly by means of abiotic stress but also by predisposing trees to pathogenic attack. However, we do not yet know how such environmental conditions alter the physiology and metabolism of trees to render them more susceptible to pathogens. To explore these mechanisms, we conditioned 3-year-old Austrian pine saplings to a simulated CC environment (combined drought and elevated temperatures), followed by pathogenic inoculation with two sister fungal species characterized by contrasting aggressiveness, Diplodia sapinea (aggressive) and D. scrobiculata (less aggressive). Lesion lengths resulting from infection were measured after 3 weeks to determine phenotypes, while dual transcriptomics analysis was conducted on tissues collected from the margins of developing lesions on separate branches 72 h post inoculation. As expected, climate change conditions enhanced host susceptibility to the less aggressive pathogen, D. scrobiculata, to a level that was not statistically different from the more aggressive D. sapinea. Under controlled climate conditions, D. sapinea induced suppression of critical pathways associated with host nitrogen and carbon metabolism, while enhancing its own carbon assimilation. This was accompanied by suppression of host defense-associated pathways. In contrast, D. scrobiculata infection induced host nitrogen and fatty acid metabolism as well as host defense response. The CC treatment, on the other hand, was associated with suppression of critical host carbon and nitrogen metabolic pathways, alongside defense associated pathways, in response to either pathogen. We propose a new working model integrating concurrent host and pathogen responses, connecting the weakened host phenotype under CC treatment with specific metabolic compartments. Our results contribute to a richer understanding of the mechanisms underlying the oft-observed increased susceptibility to fungal infection in trees under conditions of low water availability and open new areas of investigation to further integrate our knowledge in this critical aspect of tree physiology and ecology.

The World Health Organization (WHO) states that in developing nations, there are three million cases of agrochemical poisoning. The prolonged intensive and indiscriminate use of agrochemicals adversely affected the soil biodiversity, agricultural sustainability, and food safety, bringing in long-term harmful effects on nutritional security, human and animal health. Most of the agrochemicals negatively affect soil microbial functions and biochemical processes. The alteration in diversity and composition of the beneficial microbial community can be unfavorable to plant growth and development either by reducing nutrient availability or by increasing disease incidence. Currently, there is a need for qualitative, innovative, and demand-driven research in soil science, especially in developing countries for facilitating of high-quality eco-friendly research by creating a conducive and trustworthy work atmosphere, thereby rewarding productivity and merits. Hence, we reviewed (1) the impact of various agrochemicals on the soil microbial diversity and environment; (2) the importance of smallholder farmers for sustainable crop protection and enhancement solutions, and (3) management strategies that serve the scientific community, policymakers, and land managers in integrating soil enhancement and sustainability practices in smallholder farming households. The current review provides an improved understanding of agricultural soil management for food and nutritional security.

Endophytic fungi are an integral part and even seen as host organs of plant, influencing physiology, ecology, and development of host plants. However, little is known about micro-ecosystems and functional interactions of endophytic fungi in root-parasitic interactions of Cynomorium songaricum and its host Nitraria tangutorum. Here, distribution and dynamics of endophytic fungi were objectively investigated in their associations with C. songaricum and N. tangutorum based on mycobiome studies using high-throughput sequencing. Results suggest that endophytic fungi may be exchanged between C. songaricum and its host N. tangutorum probably through haustorium, connection of xylem and phloem in the vascular system. The similarity of endophytic fungal composition between C. songaricum and parasitized N. tangutorum was 3.88% which was significantly higher than the fungal similarity of 0.10% observed between C. songaricum and non-parasitized N. tangutorum. The similarities of fungal community in parasitized N. tangutorum were much closer to C. songaricum than to the non-parasitized N. tangutorum. The composition of endophytic fungi in these associations increased in progressive developmental stages of C. songaricum from sprouting to above ground emergence, and decreased subsequently probably due to host recognition and response by fungi. However, the shared fungal operational taxonomic units (OTUs) increased among interactions of C. songaricum with parasitized and non-parasitized N. tangutorum. Studies of bioactivity on culturable endophytic fungi showed that isolates such as Fusarium spp. possess the ability to promote seed germination of C. songaricum. Our study reports for the first time the special ecological system of endophytic fungi in C. songaricum and its host N. tangutorum. Overall, we hypothesize that a deeper understanding of the sharing, movement, and role of endophytic fungi between root-parasitic plant and its host may lead to finding alternative approaches to help increase the output of ethno-pharmacologically important medicinal plants.