Plants of Nicotiana benthamiana (Gray) (60 d old) were mechanically inoculated by a spreading of the fourth and fifth leaves with inoculum with or without plum pox potyvirus (PPV). Changes in growth parameters and selected photosynthetic characteristics were followed in control and inoculated plants in the locally affected leaves (LA) during 11 d after inoculation (DAI), in systemically affected leaves immature at time of inoculation (SAI) during 14-25 DAI, and in systemically affected leaves developed after the inoculation (SAD) during 28-39 DAI. The pure mechanical damage caused by inoculation induced a decrease in the net photosynthetic rate (PN) in LA and SAD leaves, and an increase in the steady-state value of the non-photochemical chlorophyll (Chl) fluorescence quenching qN. The qN increase appeared in certain time intervals in all measured leaves on plants, so it could be regarded as indication of a systemic reaction of plant to the local mechanical injury. The viral infection developed in LA leaves and spread to SAI and SAD leaves was documented by the ELISA-DASI method. The plant height and area of SAI and SAD leaves were lower in infected plants. The combined effect of mechanical damage and viral infection caused a decrease in PN only in LA and SAD leaves. In SAD leaves, an increased relative height of the J step (VJ) in the O-J-I-P Chl fluorescence transient together with a lower B/A band ratio of thermoluminescence glow curves reflected a damage to the acceptor side of photosystem 2 (PS2) caused by the viral infection, and a faster kinetics of the induction of the photochemical quenching coefficient qP of Chl fluorescence indicated a faster QA- re-oxidation in the remaining undamaged centres of PS2. and V. Hlaváčková ... [et al.].
Histological, immunohistochemical and molecular examination of bioptic samples of 30 normal adult auricular cartilages and small samples from 6 ear cartilages from aborted foetuses was performed. The adult cartilage was the tissue with minimal proliferative activity, which we were able to confirm with antibodies against Ki67 in contrast to a high proliferative activity in the auricular cartilage of foetal tissues. It may therefore be presumed that the process of foetal tissue maturation is undoubtedly associated with a significant reduction in proliferative activity. The mature lamella of the adult auricular cartilage has a histological tri-lamellar structure. There are a great number of elastic fibres in the intercellular matrix of the central zone, which are conversely present in only small amounts in both peripheral layers. While the external layer of the concave surface of the cartilage contains a fewer number of oval elements, the external layer of the convex side is composed of numerous fusiform chondrocytes. and Antibodies against various subtypes of S-100 protein showed that auricular chondrocyte activity is modified depending on the configuration of individual distinct zones (isoforms A1, A6, B2 and P were positive in all layers, isoforms A2 and A2 in peripheral zones). The most active cells metabolically are most likely chondrocytes in both external layers adjacent to the perichondrium. We have also demonstrated α-smooth muscle actin (SMA)-positive chondrocytes in both peripheral layers of the auricular cartilage adjacent to the perichondrium. In addition, we found definite differences in the distribution of actin-positive cells depending on the external shape of the pinna. The majority of these fusiform cells were localised primarily in the areas of great curvature of the pinna, especially the convex side, as mentioned above. On the basis of these unique structural features we assume that the ear cartilage may embody an example of the socalled intelligent biological material, which has its internal structure made in such a way as to more easily develop and yet still maintain all the shape characteristics of the human auricle. The knowledge of these specific structural characteristics is important especially for use of auricular cartilage in auricular reconstruction.