Raman Spectroscopy Applications in Grapevine: Metabolic Analysis of Plants Infected by Two Different Viruses

Abstract

Grapevine is one of the most cultivated fruit plant among economically relevant species in the world. It is vegetatively propagated and can be attacked by more than 80 viruses with possible detrimental effects on crop yield and wine quality. Preventive measures relying on extensive and robust diagnosis are fundamental to guarantee the use of virus-free grapevine plants and to manage its diseases. New phenotyping techniques for non-invasive identification of biochemical changes occurring during virus infection can be used for rapid diagnostic purposes. Here, we have investigated the potential of Raman spectroscopy (RS) to identify the presence of two different viruses, grapevine fan leaf virus (GFLV) and grapevine rupestris stem pitting-associated virus (GRSPaV) in Vitis vinifera cv. Chardonnay. We showed that RS can discriminate healthy plants from those infected by each of the two viruses, even in the absence of visible symptoms, with accuracy up to 100% and 80% for GFLV and GRSPaV, respectively. Chemometric analyses of the Raman spectra followed by chemical measurements showed that RS could probe a decrease in the carotenoid content in infected leaves, more profoundly altered by GFLV infection. Transcriptional analysis of genes involved in the carotenoid pathway confirmed that this biosynthetic process is altered during infection. These results indicate that RS is a cutting-edge alternative for a real-time dynamic monitoring of pathogens in grapevine plants and can be useful for studying the metabolic changes ensuing from plant stresses.

D3.2 - Raman Spectroscopy applied to detection of grapevine’s disease: the case of Esca detection

“…The spectra of grapevine leaves (Fig. 1) showed vibrational bands assigned to carotenoids, polyphenols and chlorophylls [9] [10]. The typical spectra are similar for different classes with only minimal changes, thus indicating that a data analysis is necessary to extract information from the data.…”

Using Raman spectroscopy for early detection of resistance-breaking strains of tomato spotted wilt orthotospovirus in tomatoes

“…Carotenoids act as quenchers for singlet oxygen and free radicals in a process that leads to their degradation ( Mordi et al., 2020 ). Furthermore, chlorophyll concentration is well known to decrease during viral infection ( González et al., 1997 ; Kapinga et al., 2009 ; Mandrile et al., 2022 ). This provides strong evidence that RS is capable of detecting minute biomolecular changes in content early in TSWV infection.…”

Early Detection of Esca Disease in Asymptomatic Vines by Raman Spectroscopy

“…Finally, carotenoids are at the base of the synthesis of important plant hormones such as abscisic acid and strigolactones. No specific study has looked at alterations in specific carotenoid and apocarotenoid contents upon esca-disease development, but the association to asymptomatic grapevine virus infection was recently shown [13]. Nevertheless, the concentration of carotenoids provides information about plant stress, and its capacity to endure it [26].…”

“…RS allows for confirmatory diagnosis of biotic [8] and abiotic stresses [9] on plants. For example, RS was used for diagnostics of Huanglongbing (HLB) disease on both orange and grapefruit trees [10], as well as the detection and identification of various fungal and viral infections [11,12,13]. The Raman technique shows distinct advantages over established in vivo plant stress sensing techniques, such as reflectance spectroscopy [14], hyperspectral band remote sensing [15], chlorophyll fluorescence spectroscopy [16], IR thermal imaging, terahertz time-domain spectroscopy.…”