Compared Anatomy of Young Leaves of Prunus persica (L.) Batsch with Different Degrees of Susceptibility to Taphrina deformans (Berk.) Tul

Abstract

Anatomical observations of leaves infected by Taphrina deformans were studied in tolerant peach trees (TPT) and in very susceptible (VSPT) ones. Leaves from the first sampling (2nd April) showed hyphae penetrating through the stomata or into the cuticle of the host tissue; anatomical structures of leaf sections were similar for both TPT and VSPT. The ultrastructure of the leaves of TPT showed seemingly normal mesophyll cells. In contrast, mesophyll cells of the VSPT showed important signs of degradation. Cells were organelle‐free and the middle lamella was expanded and invaded by hyphae of T. deformans. In some samples, the leaves of TPT showed deformed epidermal cells, loss of some spongy cells and increase of the intercellular spaces and division of the palisade cells. The pathogen proliferation in the leaves of the VSPT was considerably superior. In this case, stimulation of cell division occurred in the abaxial epidermis. Cells showed periclinal and oblique divisions, with an increased number of plasmodesmata; palisade or spongy cells were not differentiable. Leaves from TPT collected on 26th April showed hyphae with a non‐cylindrical section and with a squashed aspect. The hyphae were very evident in the intercellular spaces, showing abundant endoplasmic reticulum of rough type (RER) in the cytoplasm. On the other hand, epidermis of the leaves of the VSPT had numerous hyphae under the cuticle, which were growing in a thick pectin matrix. Leaves from TPT and VSPT collected on 6th May showed relevant differences. The leaves of TPT had a palisade mesophyll with fewer cells but with active chloroplasts. In contrast, the leaves from VSPT showed empty mesophyll cells, the cytoplasm was collapsed and the adaxial epidermis was covered with the fungus fructification. The observed anatomical and ultrastructural differences of leaves from TPT and VSPT confirm a different behaviour in plant‐host reaction at early stages of infection.

Unravelling early events in the Taphrina deformans–Prunus persica interaction: an insight into the differential responses in resistant and susceptible genotypes

“…In susceptible plants, other ultrastructural differences become evident on pathogen proliferation (Giordani et al . ).…”

“…Although not tested, the dissolution of the middle lamella suggests the action of other lytic enzymes. In susceptible plants, other ultrastructural differences become evident on pathogen proliferation (Giordani et al 2013).…”

Correlation of trichome density and length and polyphenol fluorescence with susceptibility of five cucurbits to Didymella bryoniae

“…This is unexpected, as the fungitoxic effect of phenolic compounds is well documented in cucumber (Daayf et al, 1997a;Daayf et al, 1997b;Fawe et al, 1998;Daayf et al, 2000). Moreover, there are several reports of the general finding that plants that are more resistant to fungal pathogens display a substantially higher concentration of phenolic compounds in their tissues (Gradziel et al, 1998;Mayer, 2006;Giordani et al, 2013). In the five cucurbits examined in this study, the defense strategy of the more susceptible species might rely too strongly on the production of polyphenols, or the less susceptible species might produce other, more effective chemical compounds that enable them to defend themselves against D. bryoniae.…”

“…In hops, trichomes are 13 times larger than normal epidermal cells and show an increased susceptibility to powdery mildew, because they have a lower level of defense reactions and physiological activity than other cells (Oberhollenzer et al, 2013). A high polyphenol content in plant tissue has been shown to confer resistance to ascomycete pathogens (Treutter and Feucht, 1990;Gradziel et al, 1998;Mayer, 2006;Giordani et al, 2013). Beckman et al (1972) observed stored phenolics in bulbous trichomes and later pointed out that phenolicstoring cells play key roles in the defense strategy of plants (Beckman, 2000).…”

Current Status of Peach Leaf Curl Disease in Pakistan and Future Management Strategies

“…These changes indicate structural changes in the leaf, with the palisade layer becoming indistinguishable from the spongy mesophyll (Matuyama and Misawa 1962;Marte and Gargiulo 1972;Moscatello et al 2017). During the infection, alterations in the anatomy of the host cells have also been observed (Giordani et al 2013). Changes in the plant cell wall at its fungal interface, invaginations of plasmalemma and tonoplast, and an increase in the number of plasmodesmata are some of the modifications observed during infection.…”