No abstract

Bovine mastitis is an important animal production disease that affects the dairy industry globally. Studies have estimated the prevalence of this disease in approximately 30% of African countries, with the highest prevalence found in Ethiopia. This is despite the wide cattle distribution in Africa, and the largest number of dairy farms and herds in countries such as South Africa, Kenya and Uganda. Furthermore, the estimated financial losses due to direct and indirect impacts of bovine mastitis are lacking in this continent. Therefore, intensive research efforts will help determine the continent-wide economic impacts and advance careful monitoring of disease prevalence and epidemiology. Here, published cases supporting the occurrence and importance of bovine mastitis in certain regions of Africa are outlined.

Nearly all microbes including fungi grow firmly attached to surfaces as a biofilm. Yet, attention towards fungal interactions with plants and the environment is dedicated to free-floating (planktonic) cells. Fungal biofilms are generally thought to configure interactions across and among plant populations. Despite this, plant fungal biofilm research lags far behind the research on biofilms of medically important fungi. The deficit in noticing and exploring this research avenue could limit disease management and plant improvement programs. Here we provide the current state of knowledge of fungal biofilms and the different pivotal ecological roles they impart in the context of disease, through leveraging evidence across medically important fungi, secondary metabolite production, plant beneficial functions and climate change. We also provide views on several important information gaps potentially hampering plant fungal biofilm research, and propose a way forward to address these gaps.

Phytopathogenic oomycetes are known to successfully infect their hosts due to their ability to secrete effector proteins. Of interest to many researchers are effectors with the N-terminal RxLR motif (Arginine-any amino acid-Leucine-Arginine). Owing to advances in genome sequencing, we can now comprehend the high level of diversity among oomycete effectors, and similarly, their conservation within and among species referred to here as "core" RxLR effectors (CREs). Currently, there is a considerable number of CREs that have been identified in oomycetes. Functional characterization of these CREs propose their virulence role with the potential of targeting central cellular processes that are conserved across diverse plant species. We reason that effectors that are highly conserved and recognized by the host, could be harnessed in engineering plants for durable as well as broad-spectrum resistance.

Plants are constantly challenged by various environmental stressors ranging from abiotic—sunlight, elevated temperatures, drought, and nutrient deficits, to biotic factors—microbial pathogens and insect pests. These not only affect the quality of harvest but also the yield, leading to substantial annual crop losses, worldwide. Although plants have a multi-layered immune system, phytopathogens such as species of the oomycete genus Phytophthora, can employ elaborate mechanisms to breach this defense. For the last two decades, researchers have focused on the co-evolution between Phytophthora and interacting hosts to decouple the mechanisms governing their molecular associations. This has provided a comprehensive understanding of the pathobiology of plants affected by oomycetes. Ultimately, this is important for the development of strategies to sustainably improve agricultural production. Therefore, this paper discusses the present-day state of knowledge of the strategic mode of operation employed by species of Phytophthora for successful infection. Specifically, we consider motility, attachment, and host cell wall degradation used by these pathogenic species to obtain nutrients from their host. Also discussed is an array of effector types from apoplastic (hydrolytic proteins, protease inhibitors, elicitins) to cytoplastic (RxLRs, named after Arginine-any amino acid-Leucine-Arginine consensus sequence and CRNs, for CRinkling and Necrosis), which upon liberation can subvert the immune response and promote diseases in plants.