Changes in the chlorophyll content of grape leaves could provide a physiological index for responses and adaptation to UV‐C radiation

Abstract

Stilbenes are a group of phytoalexins that play an important role in grapevine (Vitis) basal immunity and can be induced by biotic and abiotic stresses. The levels of chlorophylls, the main pigments in plant cells, can also indicate the tolerance of plants to various stresses. Here, the response of different grapevine genotypes to UV‐C radiation treatment was tested and the abundance of chlorophyll in the Hoe29 and Ke53 genotypes was observed to increase significantly within 6 h of UV‐C treatment. Conversely, chlorophyll levels decreased markedly in the Augster Weiss and Müller–Thurgau genotypes. Furthermore, stilbene abundance increased substantially in the Hoe29, Ke53, Ke83 and Pinot Blanc genotypes, but increased only slightly in Augster Weiss and Müller–Thurgau. The expression of resveratrol synthase, which encodes a key enzyme in the stilbene synthesis pathway, increased in Hoe29, Ke53, Ke83 and Pinot Blanc following UV‐C treatment, in a manner consistent with stilbene accumulation. In addition, we observed that reactive oxygen species (ROS) provide a key trigger in physiological responses and changes in secondary metabolite contents. In summary, the results from this study support a link between ROS, chlorophyll levels and genetic diversity for stilbene abundance in different grape genotypes, providing insights into mechanisms for plant physiological and biochemical responses and adaptations to stress.

Extenuating role of lycopene against 254-nm UV-C radiation-mediated damages in Allium cepa L. roots

“…However, MDA amount of UV-C-treated G4 was about 3.5 times that of the control group indicating that an oxidative imbalance took place following UV exposure in A. cepa roots. Our results were in accordance with the data of Luo et al ( 2019 ) who revealed that UV-C administration triggered a remarkable induction in MDA levels in grape leaves. Another study on Nicotiana tabacum callus showed that 254-nm UV radiation caused a remarkable increase in MDA accumulation from the 6 th hour of application (Zacchini and de Agazio 2004 ).…”

A Comparison of Cytotoxic and Genotoxic Damages Induced by 254 Nm and 365 Nm Radiation: Allium Cepa L. Model

“…In our study, much greater increase in MDA content in the 254 nm UV-treated group compared to the 365 nm UV-treated group indicated that UV-C caused a more serious oxidative burst in Allium root cells. Similar to our results,Luo et al (2019) reported a remarkable increase in MDA levels in UV-C radiation-exposed grapes. In another study, UV-C pulses triggered signi cant increases in MDA contents of tobacco callus in a time-dependent manner(Zacchini and de Agazio 2004).…”

“…According toUrban et al (2016), lipid peroxidation is one of the direct effects of ionizing radiation in plants. As a cytotoxic material, MDA points out both the degree of lipid peroxidation in biological membranes caused by the over-production of reactive oxygen species (ROS) and the e ciency of the stress defense(Skórzyńska 2007;Luo et al 2019). In our study, much greater increase in MDA content in the 254 nm UV-treated group compared to the 365 nm UV-treated group indicated that UV-C caused a more serious oxidative burst in Allium root cells.…”

Implication of Row Orientation Changes on Fruit Parameters of Vitis vinifera L. cv. Riesling in Steep Slope Vineyards

“…However, excessive light conditions bare the risk of damaging proteins and the light harvesting pigments of the photosynthetic system [73]. High irradiation of leaf tissue results in significantly lower leaf chlorophyll content compared to shaded leaves [74,75], which was also confirmed for exposed canopies in this study (Figure 4). Suggested optimum values for leaf Chl i content were seldom reached by the different canopy sites of the examined steep slope management systems [31].…”