Fusarium oxysporum f. sp. lycopersici causal agent of vascular wilt disease of tomato: Biology to diversity– A review

Abstract

Tomato (Lycopersicon esculentum) is one of the widely grown vegetables worldwide. Fusarium oxysporum f. sp. lycopersici (FOL) is the significant contributory pathogen of tomato vascular wilt. The initial symptoms of the disease appear in the lower leaves gradually, trail by wilting of the plants. It has been reported that FOL penetrates the tomato plant, colonizing and leaving the vascular tissue dark brown, and this discoloration extends to the apex, leading to the plants wilting, collapsing and dying. Therefore, it has been widely accepted that wilting caused by this fungus is the result of a combination of various physiological activities, including the accumulation of fungal mycelia in and around xylem, mycotoxin production, inactivation of host defense, and the production of tyloses; however, wilting symptoms are variable. Therefore, the selection of molecular markers may be a more effective means of screening tomato races. Several studies on the detection of FOL have been carried out and have suggested the potency of the technique for diagnosing FOL. This review focuses on biology and variability of FOL, understanding and presenting a holistic picture of the vascular wilt disease of tomato in relation to disease model, biology, virulence. We conclude that genomic and proteomic approachesare greater tools for identification of informative candidates involved in pathogenicity, which can be considered as one of the approaches in managing the disease.

Boosting photosynthetic machinery and defense priming with chitosan application on tomato plants infected with Fusarium oxysporum f. sp. lycopersici

“…Vascular pathogens such as Fol disturb water and nutrient absorption processes in plants, decrease plant growth, and affect transpiration, respiration, and photosynthesis (Yadeta and Thomma, 2013). Fol colonizes the elements of the xylem and causes the formation of gums and tylose, obstructing and increasing resistance in rising water, and decreasing the xylem and leaf water potential (Srinivas et al, 2019;Chekali et al, 2011;Lushchak, 2011;Duniway, 1971). Consequently, stomatal closure increases and CO2 absorption is reduced in detriment of photosynthetic activity, generating decreases in the quantum efficiency of photosystem II (PSII).…”

Evaluating the tradeoffs of a generalist parasitoid fungus, Ophiocordyceps unilateralis, on different sympatric ant hosts

“…Here, we observed that the locations of host ants on the leaf undersides were highly stable and were always on a major primary vein. Many fungal species are not only opportunistic pathogens in animals but also plant-pathogenic fungi [33][34][35] . We hypothesize that the vascularized tissue of leaves may provide a nutritional supplement for the developing fungus, because leaf biting may create an opening where fungi gain ready access to plant nutrients.…”

The Role of Saccharides in the Mechanisms of Pathogenicity of Fusarium oxysporum f. sp. lupini in Yellow Lupine (Lupinus luteus L.)

“…Therefore, it was important in this study to compare the plant’s biomass, especially the fresh weight of the embryo axes cultured under different trophic conditions, with high sugar levels and with sugar deficiency. Colonization and clogging of vessels, in addition to the secretion of several toxins by the fungus (fusaric acid, lycomarasmin, and dehydrofusaric acid), play a major role in wilt symptom development and progression [ 20 ]. As reported by Perincherry et al [ 21 ], among the Fusarium mycotoxins, the primarily concerned ones are the trichothecenes, fumonisins, and zearalenones.…”